Cheap Laptop PCs Desktops

1) Expired Domain Finder Script:
This PHP script has become a very hot item within the last 6 months! This Script will look up domains that have expired, or are about to expire in both the Yahoo! Directory, AND Dmoz Directory! This script will also allow your customers to monitor domains that they are interested in; it has a domain digger, and has PayPal IPN functionality built right into the script! There are many websites selling memberships using this script for up to as much as $29.99 per month! The script comes with an administrator section where you can manage the look, and feel of your website, as well as manage your members, set up different membership packages and more! The fact that this script uses MySQL means that it is extremely fast, and can look up expired or soon to expire domains in an instant!

2) PHP Auto Hits Script:
With this new PHP Auto Hits script, you can set up a profitable traffic exchange service, complete with an auto-surfer and everything else.

The Following Scripts ALL come with Royalty-Free License!

3) PHP Link Listing Script:
The Script Is Unique from Other Link Listing Scripts In That It Creates Different “Rooms” For Different Links! Making This Powerful Script its Own Little Web Surfing Tool For The Visitor Of The Site! It Is More Or Less A Nice Little Search Engine! Once A Visitor Signs Up For The Website they are placed on a mailing list, and the script automatically sends out an email to each visitor every time a new link is added! You Can Make Money Selling Advertising To Other Webmasters! The Automatic Email Will Guarantee Your advertisers that their link will be seen! The Visitor will have a choice on whether to receive an email for each link OR one email with all new links listed! There is a top ten list for the most popular links! When you add a new wing, you choose a name and also who can get there. You may have rooms that are off-limits to the public. These private rooms will never be shown to the public or appear in the Top 10, Last 10 and Random lists! A very nice script!

4) PHP MySQL Yahoo Style Link Directory/Search Engine:
This Script is a PHP and MySQL powered links database which allows You to run a database driven categorized links section on a web site – similar in structure to Yahoo or any other categorized links collection. Features include:
* Fully database driven utilizing MySQL.
* Full template system allowing you to control the HTML output of the script without needing to alter any of the PHP code.
* Easily customizable if you wish to alter the script in any way.
* Very easy to admin via the web – log in and add / edit categories and links.
* Visitors to your site can recommend new links, which you can then validate.
* Allows visitors to rate your links from 1-10, and displays average rating.
* Rating a link more than once is discouraged using cookies.
* Number of hits each link has received is recorded and displayed.
* Very easy to set up and use, thanks to an installation script and config file.
* Built in Search Feature.
* Most popular, top rated and newest links pages.

5) PHP MySQL Website Stats Business:
This script is simply awesome! It is a new PHP script, and will allow you to set up your own link tracking business! There are two different memberships you can sell with this script, and both are beneficial to you! The lite membership costs less, but requires your customer’s to keep a banner to your website on theirs in order to track their stats! The pro membership of course costs more (Whatever price you set!) and does not require the customer to link to your site! The script automatically takes payments via the PayPal subscription method so you are insured to receive your fees every month! It also keeps track of your customer’s statistics daily, weekly, and monthly! This is a VERY nice script!

6) Automated Form Submission Prevention Script
Did you ever sign up for a website that makes you enter a combination of distorted letters and numbers to prevent automated signup and wish you could add that script to your site? Well now you can. This script generates distorted images of random sequences that most humans can read, but computers cannot, therefore to prevent automated robots from submitting forms and signing up for your service.

7) A Sophisticated PHP Ecommerce Site
This script will allow you to run a very nice, and very secure ecommerce area or store front from your website! It is very easy to install and comes with an installer script so that all you need to do to set it up is point and click! This in-depth script will keep your customer’s entire records safe in a database, and will allow you to update orders and more! Highly Recommended!

The Well Known osCommerce PHP Shopping Cart!
osCommerce is quickly becoming the shopping cart of choice for many online merchants! This script is simply AWESOME! You can literally have a store set up and ready to take orders within an hour! The script comes with a VERY easy to use admin section where you add all of the products, manage customers, shipping, tax, payment process, inventory, and just so much more to mention! You can use MANY, MANY different payment gateways with osCommerce including PayPal, 2Checkout, authorize.net, and many more! This version of the script is NOT simply the snapshot version THIS IS THE MILESTONE RELEASE!

9) Your Own FTP Program Written In PHP:
This is another truly GREAT PHP script! This script actually allows you to set-up and run YOUR OWN FTP SERVER! The best thing about having your own FTP server is You know who is using your FTP and if there is someone trying to retrieve your password for your server (which is impossible to do with this script I might add)! You will be able to set up and use your own FTP program with ALL of the benefits of the expensive FTP software! If you are a web host, or have any anonymous FTP users this script will also let your customers use it for their uploading purposes as well!

10) A FAQ Generator PHP Script:
Have you ever wanted to find an easier way to add your customer’s frequently asked questions to your website? This script will easily allow you to add topics, and questions to your new FAQ page! It is very easy to install, And comes with an administration section so that you can add the information to your page/pages directly from your web browser! Every site needs to have a FAQ page for the sake of its clients, and this script provides the easiest way to build one! Comes With Reseller Rights

11) Two Very Nice PHP Toplists Scripts!
The First Is A Detailed PHP Script With MANY Features: If you have ever wanted to run your own toplist website THIS IS THE SCRIPT FOR YOU! It comes with such advanced features as Anti-Cheating, Rules members MUST follow, Easy to match the look of your website, looks up lost passwords, allows you to decide if you want to allow banners to be used by your visitors, Allows you to sell advertising for your toplist, and a lot more! A very sophisticated script!

12) The Second Is A VERY Nicely Designed PHP Topsite Script:
This toplist script has a VERY nice design to it! It is very easy to install, and is template based so all of the HTML work has already been done for you! This toplist script is limited ONLY BY YOU! You can allow as many or as few links to be added to the entire list, or even page by page! Many toplists make the major search engines fast due to the amount of links, and visitors they receive! This is a great way to SELL advertising Or simply advertise your own websites!

13) Two Auction Scripts 1 PHP, And 1 Perl/CGI!
The First Is a Popular PHP Auction script! This is a VERY nice PHP auction script! It Is a very easy script to install! There are Many Premium features that come with this auction script! Once it is installed you can easily manage your new auction site from a secure administration section! You can manage the look of your website, manage all of your users, approve, and delete members, send out a newsletter, and much more right from your browser! The script will automatically notify your customers when they register, get outbid, win an auction, or owe you money! Once it is installed it is virtually a hands off business! Comes With Reseller Rights

14) The Second Is Another Popular CGI Auction Script!
A Perl Auction Script That Is Used WIDELY By webmasters! The Script Create auction sites with unlimited categories, and set the price you wish to charge! There is only 1 file to upload to your CGI-Bin! Make a few changes, and WOW! You’ve got your own Auction website! Comes With Reseller Rights

15) Two Affiliate Scripts Both Written In PHP!
The First Is A Very Simple Script To Run: This PHP MySQL script will allow you to run your own affiliate program! One of the easiest ways to get QUALITY traffic to your website is to start your own affiliate program! Pay your affiliates per click, per sale, or in tiers! You will find that when you get more and more affiliates signed up, your sales will skyrocket!

16) The Second Affiliate Script Is A More Sophisticated Script:
This PHP MySQL script has taken running an affiliate program from your website to the next level! It is very easy to install, And The use of MySQL will securely keep your user’s information confidential, and keeps excellent track of all commissions earned by your affiliates! To further secure the scripts it also makes excellent use of sessions! If you have a business online, and do not have an affiliate program, you are missing out on some serious cash!

17) POP-UP Creator:
This set of scripts will amaze you when you see how easy it is to create your own POP-UPS on your website! The Simple To Use Software Makes Creating Popups So Easy, A Child Can Do It! If You Ever Wanted To Use The Power of Popups, This Software Is For You! This version of the POP-UP generator also supports the cookie based pop-ups!

18) PHP Authentication Script NICE!:
If you are looking for a way to secure an area of your website this is one of the most powerful, and secure ways to do so! This PHP MySQL script secures your member’s passwords via the powerful MD5 in MySQL! Your members can finally feel secure about their passwords being secure when you use this script! The script is VERY easy to install!

19) The Perpetual Traffic Generator:
If you are in need of traffic to your website this script is for you! It Will Increases your traffic by a whopping 927%, Allows you to generate traffic 24/7 absolutely FREE! Frees you up from clicking away mindlessly in front of the PC to chalk up traffic credits. Just set it up and it’ll do all the work for you. Sends a stampede of visitors to your website the very day you invest in this incredible web marketing tool Makes you kick butt profit in the traffic generation process!

20) A PHP Links Exchange Website Script:
This link exchange script is a PHP script that allows your visitors to sign up for an account, and add their link to your website! It keeps track of all dead links on your website so that you can easily maintain your site, and keep dead links off of your link exchange! It also has an administration section that is password protected, and allows you to add categories, links, approve, disapprove, and delete links right from your browser! This would be a very nice script to start up a paid or free link exchange! Either way you win because Linking is the best way to get listed in the major search engines!

21) Two ClickBank Scripts
The First Is The Affiliate Linkmaster: This Script Stops you from losing your hard earned affiliate commission. No HTML coding! Just click ‘Generate Code’ and Instant affiliate link masker does The Rest For You! Instant affiliate link masker puts more money in your bank account and NOT somebody else’s! Makes sure you get credit for your affiliate referrals. Quickly create your masked affiliate link in less than 5 minutes. No coding involved, Instant Affiliate Link Masker automatically creates your affiliate web page for you With Instant affiliate link masker you can instantly protect and encrypt your affiliate link. Encrypt an unlimited number of affiliate links. No software to install, just download, unzip and run!

22) The Second ClickBank Script Is The Instant Site Maker:
You can automatically build profit pulling web pages in an instant! Quickly create stunning web pages in less than 5 minutes. No coding involved, Instant Site Maker automatically creates your web pages for you. No HTML coding! Just click ‘Generate Code’ and Instant Site Maker creates your sales page, thank you page and even automatically creates your ClickBank instant download link. No software to install – just download and run. (Requires Internet Explorer version 5.5 or higher) Forget about difficult and tedious hand coding of your web pages . . . Instant Site Maker does it for you and without HTML errors. Instant Site Maker lets you create your own custom web pages instantly. No need to learn HTML or spend hours debugging code, just paste your sales copy straight from MS Word. With Instant Site Maker you can instantly and easily add testimonials to your web page. Quickly and easily create the ClickBank order links so customers can immediately order products from your site. Quickly and easily create your ClickBank thank you page. Quickly create your product download link – so customers’ get their products automatically as soon as their order is processed. Quickly and easily create web pages that are fully optimized for high search engine ranking because Instant Site Maker is designed to automatically include search engine friendly HTML code (meta tags) for your pages.

23) A “Suggest My Site” Script
Let your visitors suggest your site easily by just filling out a form. This script checks the required fields, sends a thank you message to the person who suggests your site and attaches a pre-defined text to the suggestion mail. Supports both English and Turkish languages.

24) A PHP Script For Building A Web Ring:
A Webring Script! Create Your Own Network Of Websites by creating a webring with this nice script! It will automatically email the members of your webring, and keeps detailed stats of the visitors you receive to your webring! A Very nice well designed script, and very easy to install!

25) A PayPal Store Shopping Cart:
This shopping cart script is a data base driven content management system using PHP and MySQL on a Unix platform (it may work on a windows but I have not tested yet). It supports PayPal IPN, LinkPoint, Worldpay and Authorize.net integration and for those who have a merchant account at their bank there is a way to store credit card info encrypted on the server using mcrypt; it uses a key for encrypting/decrypting CC numbers to and from the data base in SSL.

26) PHP Form To Email Script SECURE!:
It is hard to find a form mail script that will securely deliver your client’s results every time, while concealing your email from the SPAM bots! This Script Will Do Just That! The script was cleverly written to disguise your email address, and yet get the results of every form filled out straight to your inbox! We recommend this script highly, and our clients LOVE it!

27) A Online MultiPlayer Chess Script
This is an advanced WebChess game where two people can meet up online and play vs. each other. It has many advanced features such as Pawn Promotion, Move Validations, Tells if King is checked, and many, many more. It requires PHP and at least one MySQL Database.

28) A Super Easy Administration Program
With this super easy admin program user’s can create, modify, and delete files and directories. The code is in a modular format so new modules can be easily created and added. The download is small and contains no un-necessary images or advertising. This is the newest version which has encrypted passwords and now works on newer PHP systems and does not require register_globals to be on.

29) A Sharable Web-Based Address Book Script
This script is a web based address book, sharable, multilingual with data import/export features and is based on PHP4 and MySQL. Main features include Create/Access your address book on an internet website; import/export your addresses from/to your email client and/or other address manager applications, users and contacts groups management, group’s members messages send facilities (small mailing list utilities which won’t replace a mailing list manager). This script is also tunable (colors, fonts, content display, language). This script also comes with installation instructions in French (other than English).

30) A News Publishing Script
With this state-of-the-art news publishing script written in PHP and using MySQL, you can post news any time anywhere to your website by using the password protected administration section. Some features include; post news, delete news, delete all news, edit news, delete multiple news, change status (make visible/invisible), supports multi-language, supports CSS, you can call the script via JavaScript, allow/disallow html, display news as NEW for any amount of time, display the latest news, display all the news, display full story and display how many times an article has been read.

31) A “Users Online” Script
This “Users Online” script is written in PHP and allows you to display the exact amount of online users on your website in a very convenient and efficient way. “Users Online” scripts make your website look high-tech and professional and are something no webmaster should be without on his/her website.

32) Awesome File Transfer Script
This awesome file transfer script allows your users to upload and download files from your server; it id highly configurable with user accounts support. Users can give descriptions to files, create and delete their own files and directories and sort lists by filename, upload date or downloads. Currently supports English, Italian and Spanish, but you can customize the application in your language too. If you own a community website such as an online forum or wish to start one, this is the perfect script for you either as a stand-alone or an extra service on your website. This script can get visitors to come and keep coming back time and time again.

33) Affiliate Banner Rotation Script
This affiliate banner rotation script is probably the most easiest to install ad manager on the web! All you’ve have to do is upload a list of all your affiliate advertising codes in a list and that is about it. Simply include the script using a PHP include code (included) and you’re on you way fast and easy. The script changes which advertisement will be viewed next making sure that all your adverts get equal viewing (does NOT show at random like most scripts) and the script requires the page to be refreshed to change the advertisement seen so that you get extended viewing per banner.

34 Simply AWESOME Dating Website Script
This is simply one of the best dating scripts available written in PHP & MySQL. Several cool features available in this script are users can add, edit and delete profiles, upload up to three photos, user messaging system, users can set to be notified when another user will reads their message, users are given numeric usernames to increase privacy, who is online feature, recommend us feature, current birthday list and statistics on the main page (amount of men and woman members).

35) Simple yet Powerful Download Counter Script!
This simple yet powerful download counter will log the details of anyone who downloads any file you specify. It will log their IP Address, Remote Address, browser type and even operating system and you can easily modify and add new downloads through a powerful password protected admin panel. This script can keep track of an unlimited number of files. MySQL and SSI (Server Side Includes) are required.

36) Another “Users Online” Script!
This Users Online script shows how many users are on your website, you can change the time in which the MySQL Database Table is refreshed so you can count users online per minute, hour, week etc! This script is more user friendly and comes with a “setup.php” installation file which will set the script up for you.

37) Text based counter written in PHP
You can quit paying for traffic counter services. This script is a very simple and super easy to install webpage hit counter. The font and color of the counter are completely customizable and there are only 2 files to upload to your web server. Plus you will even have the ability to separate the thousands for added customization.

38) A FAQ manager written in PHP and MySQL
This PHP “FAQ” manager is a simple script yet powerful script that will help you to create (and manage) a FAQ (Frequently Asked Questions) page on your site. It is written in PHP, MySQL and FastTemplate so it is fast and easy to configure. Every website needs a FAQ page so you don’t look like just another “fly-by-night” website that won’t be in business for longer than a month or two.

39) A Sports League, Fixture and Prediction Management Script written in PHP and MySQL!
This powerful script is a football management software written in PHP that use a MySQL database. It has a modular design and comes with two free modules. The league module features wizards for managing a football league, fixtures, games, teams, results, divisions, etc. League team statistics are automatically calculated and updated every time a game is played/entered. The news module features an HTML news creator/editor that can be used to post news.

40) A PHP Whois Lookup Script!
This script is a ready to use WHOIS lookup PHP script that all you have to do is unpack, upload and you are ready to go. The script checks for .com, .net, .org, .biz and .info domain names. No PHP knowledge required! This is the latest updated version which is super easily to customize; you can easily change the language (few lines) or disable domains you don’t need.

41) HOT PHP Visitor Logging Script!
This Hot PHP script is a state-of-the-art visitor logging script that can easily display 10 vital statistics about your users. The advanced visit logs this script generator tells you the IP Address, language, browser, operating system, if the user is new to your website, date and time of visit, last visit, days since last visit, referrer page and the keywords they used to find your website (if applicable).

42) Awesome LiveHelp Script!
A live Help support chat system that allows the operators of the websites to monitor their visitors as they are browsing the site and proactively open a chat session with the visitor. Other features include either text based database or MySQL database, chat notification, user is typing message, multiple chat sessions and multiple operators.

43) PHP & MySQL Content Management System
This hot script installs in just minutes on any Windows, UNIX, Linux, or BSD based web server and setup is made super easy through a complete web-based installation system and an included installation guide. Once this software is installed changes to the content of your website is made in complete real-time through an easy to use web-based administration control panel. The control panel allows you to tune every aspect of your web sites visual appearance and layout and also provides an easy to use content authoring & management approach unique to this script. The visual appearance, layout properties, and navigation scheme of the web site can be instantly changed at a global level selecting from installed professional looking skins and navigation bars which will automatically reformat the look of your content “on the fly” while leaving your database driven content completely untouched. Users of this script will find that authoring and editing content for the web site is a snap by making use of the enhanced authoring interface which includes support for both WYSIWYG editors and plain text/HTML markup languages. Uploading and managing your files is also simple using the included file management utility allowing you to upload your images, documents and other files directly from your computers hard disk to the web server where it will become available for use in your websites content. This script is a must have for webmasters who are looking to make completely managing their website a breeze without a lot of programming knowledge.

44) An Electronic Reminder Script
This script allows web-clients to set up reminders to automatically email them at a certain time to remind them of special events. They can set up a one-time reminder or a recurring reminder and they can have it notify them in advance.

45) Hot Mailing List Script!
This mailing list management script is written in PHP and all subscriber info is stored in a MySQL database for security. Features include checking whether a subscriber is or isn’t already registered/subscribed, sending out messages at the time of subscribing and unsubscribing. A powerful and user-friendly administration control panel allows you to send messages, list and delete subscribers, supports HTML emails, gives a preview of the message before sending, logging system, Multilanguage support for English, French, Italian and German, plus a user-friendly web configuration and installation system.

46) Web-based Image Management System!
This hot web-based image management system is written in PHP and uses MySQL. It features cataloguing by standard comment fields or Photoshop-type embedded comment fields, sub-categorizing into separate repositories, database searching capability, and more. This is a great script!

47) Web-based POP Email Client!
This script is a web-based POP mail client and is very simple to install but nevertheless a quite advanced program. Some of its features include easy to install (does not require PHP to be compiled with IMAP support), reads and sends attachments, displays text/HTML attachments in-line (while still giving you the option of saving them to your hard drive), all the basic functions (send, receive, reply, reply to all, forward, delete), view all headers or the full source of the email, works even if the user has disabled cookies, localized date field, translated into several languages, can be set up to check for new messages automatically, customizable page layout, and more. Awesome Script!

48) Hot Fully Featured Web Portal System
This script is a web portal System for any webmaster; you can set it up as a storytelling software, news system, online community or whatever you want your site to be. Port the system to your local language and customize every aspect of this remarkable script. Each user can submit comments to discuss the articles, similar to Slashdot, only faster and more secure. Features include a web based admin, surveys, top page and access stats, user customizable box, friendly admin GUI with graphic topic manager, option to edit or delete stories, moderation system, customizable HTML blocks, user password encryption and retrieval, search engine, backend/headlines generation, and more. Written in PHP and requires Apache, PHP and MySQL; the over-riding development philosophy for the software is performance, privacy and security.

49) Nice FFA Link’s Page Script
Out of all the basic FFA (Free for All) links page scripts I have seen I actually like this one. This script allows visitors to add links to your page in a specified category and it is quite, if not super, easy to install and the administration area supports the deleting of existing links. FFA Link’s pages are a great way to look established and keep your visitors coming back to your website again and again.

50) Highly Advanced Guestbook Script
This highly advanced guestbook script is written in PHP and uses MySQL. It includes many useful features such as preview, templates, email notification, picture upload, page spanning, HTML tags handling, smilies, advanced guestbook codes, language support and it has a great interface to seal the deal. The admin area lets you modify, view and delete messages which gives the owner extra control.

51) Powerful Portal with Content Management
This script is highly customizable and high powered all in one system; it provides content management combined with the power of a portal by including in the core package modules features such as FAQ, polls, and forums. This script uses dynamic-template-design which means you have the power to control what your site will look like. Themes are included, but not required as you can create the page however you want and this script will just insert code wherever you want it. Written in PHP and utilizing MySQL to make it amazingly fast and secure, this script is a great solution for all size website communities.

52) PHP Online Classifieds Script
This classifieds script is an easy way to set up a classified ads website; it is designed in such a way that it is extremely easy to change the look and feel of your website. You can design your pages around the functionality of the application. Although this script does give you a lot of control over the look and feel of the site, it lacks an interface for advanced administration features. However all the administration can be done through an interface such as phpMyAdmin. If you know how to use phpMyAdmin or a similar application and are familiar with relational databases, it should be really easy to administer categories and users, etc.

53) Fully Featured Web Event Calendar
This is a customizable web calendar developed using PHP and powered by MySQL. The calendar is viewed in month format with a popup window detailing the events of each day as they are clicked on. The title and colors are fully customizable within a single file and the application can be modified to work with other database types.

54) A PHP Bookmarks/Favorites Script
This PHP Bookmarks script is a web-based program that allows you to store your bookmarks and display them in many useful ways. This script will sort your bookmarks with usability in mind, keeping often-used bookmarks at your fingertips. It has a bookmark search, private/public bookmarks, nested groups, usage rankings, popularity sorting, and a quick add feature.

55) Client Invoicing Script (HOT)
This is a MySQL powered PHP program for invoicing clients so they can view/download invoices. The system allows an administrator to enter the client details and invoices. Each client must be given a username and password to login to view their invoices and the administrator can view the full database by client, date, amount etc. There is an optional email notification system and full setup instructions included.

56) ICQ Pager Script
This script enables you to put a ICQ pager form on one or more of your web site pages; the visitors to your website then can use this form to send a short message to any ICQ user. A cool script that will keep your visitors coming and coming over and over again.

57) Frequently Asked Questions Management Script
This cool script allows you to administer a website’s frequently asked questions. It blends easily with your site, allows unlimited category depth, is searchable and allows questions to be in multiple categories. And optional user question submission option is available, along with most recently added and most popular lists.

58) ClickBank “Thank You” Page Protector Script
This is a fully automated “Thank You Page Script” which is much more powerful than a Static HTML Page. This System will verify whether your buyer is forwarded from ClickBank after payment, order Details including the ClickBank “Receipt #” will be displayed on your Thank You page, this System will collect the name and email address of your buyer, a sales report will be sent to you Instantly, a Thank You message will be sent to your buyer without any delay, it adds the buyer to your Autoresponder System so that follow-up emails will be sent to promote your other products, the whole system is fully automated and easy to customize with any text editor. With this script you don’t have to send a thank you message to your buyer manually, you don’t have to add them to your customer database yourself, you don’t have to send them promotional emails manually to promote other products, you don’t have to worry about getting repeated sales and you don’t have to worry about ebook and software Hackers.

59) MySQL Database Backup Perl Script
With so many scripts in this package using MySQL databases, I only thought it be fitting to add a script that would easily allow you to make backups of them. But this script can be used anywhere you have a MySQL database and Perl is supported, this script will save your skin over and over again.

60) CGI-Based Autoresponder Script
This script is very easy to install and in less than 10 minutes you can have it up and running which could be the reason it is the number one choice of website owners who want to take control of their online operations. It has highly advanced features that every autoresponder script should have. With this script you can send an unlimited number of follow-up emails and send follow-up emails everyday if you want (some autoresponder scripts allow you only 20 follow-up emails). This script also works on an unlimited number of subscribers and it will work great even if you have 100 or 1 million subscribers.

61) Fully Featured PHP Message Boards Script
This is a fully featured message board system and is meant to be both powerful and easy to use for the users and the administrator. With this script you can setup an online message board community which is sure to keep your visitors coming back again and again and is especially useful for people to ask support questions for your members to answer for free

62) PHP “Submit-A-Link” Style Script
This “Submit-A-Link” style script gives you the ability to offer instant links on your site. Your ads appear above and below the links and also on the submit page. You only need to edit one file and upload which makes this script very easy to use. This script also doubles as an opt in list! When anyone submit their link they give you permission to send them email. All email addresses are stored in one .txt file, making it very easy for you to add the emails to your current email program/newsletter script!

63) USENET News Client
This PHP script is a USENET news client based totally on a web interface and written in PHP4 with a MySQL database at its backend which allows you to develop useful tools such as search engines, SPAM filters, subscriptions, stats, and much more. The web interface of the “news group” script is very easy to use, and has all the advantages of the modern webmail systems because you can search through any news group anywhere in the world without the need of setting up any program.

64) PHP Image to ASCII Generator
This is a PHP program that generates ASCII images from JPG, GIF or PNG images. There are several options to alter the generated output, such as color, inversed color, font sizes, background color, line height or letter spacing only to name a few. So if you are looking to generate ASCII images from regular jpg, gif or png images, look no further as this is definitely the PHP script for you and will get the job done.

65) MySQL-Based Office Intranet Suite
This hot script is a PHP and MySQL-Based office intranet suite similar to other more expensive scripts. It includes a news page, calendar (WebCalendar), rolodex, contact log, network status page, task list, time sheet, office survey, and more. All-in-all this is a great script and will be very useful for those who are looking an office intranet solution.

66) Another PHP Web FTP Program
This tool can be used to access FTP sites from behind any firewall or proxy. Simply enter the server name (e.g. ftp.ebay.com), username and password or click the anonymous button and enter your e-mail address. The script will make a FTP connection from the server it is running from. When the file is fetched from the FTP server, it will send it to the browser via the HTTP protocol.

67) PHP Based Image Watermarking Script
This script aims to provide a simple way of marking an image with a digital “watermark” to prevent unauthorized use. It is implemented as a PHP class and should be usable inside most PHP scripts. Images are accepted either as a filename or as a reference to a PHP resource.

68) Nice Looking PHP-based eCard Script/Website
This script is a PHP-based eCard system that is easy to setup and use. The simple Administration Console allows the administrator to upload images (JPEG’s or GIF’s), add eCard categories, and modify existing settings – no more messing with HTML or PHP to get your eCard site up and running and comes with a nice looking template design to close the deal.

69) A Simple Document Management System
This script uses PHP to provide you with a great interface to a MySQL server that allows you to store and retrieve documents and to share those documents between users. In addition, the system uses ACL (Access Control Lists) to grant access rights to documents on a per-user basis. It allows you to distribute project documentation on a need-to-know basis, whilst keeping a central repository of documents that is accessible to all team members and easy to manage.

70) PHP-based Instant Photo Gallery Script
This script is a tool for posting customizable, template based galleries, by simply uploading images to the server the script is running on. The script scans the directory you point it to (via a query string), and then it stores the list of images it retrieves in an array that is POSTED from page to page as the user moves through the gallery. This method of file-list-passing makes this script significantly more efficient than gallery tools that scan image directories each time they generate a page.

71) Anchor Tag Creator Script
This nifty little script pre-processes HTML before displaying it to the browser locating user-defined keywords in the HTML string (or plain text for that matter), and subsequently replacing the keywords with anchor tags of user-defined URL’s. Pre-defined ‘template’ anchor tags are available for Google.com searches or Dictionary.com lookups. This script takes care that no replacement inside an HTML tag is made and also avoids matching keywords which were found inside of a pre-existing anchor tag’s text. With this script your website vistors experiences are enhanced by providing links to dictionary definitions, web searches or any user-defined URL’s. And whats even better is that web content developers are provided with a simple way to link keywords without having to manually create all those anchor tags.

72) CGI Customer Tracking System Script
You can now let your customers submit their request/questions and you will get email notifications in order to respond to your customers. A simple and colorful way of tracking customer requests with an easily configurable customer request form. A sort on customer, status of ticket, date submitted and even agents is available.

73) Advanced Photo/Image Gallery Script
This PHP & MySQL based photo album features include unlimited albums and photos, users and comments, automatically add and remove photos, thumbnail support, multilanguage and themes.

74) Awesome PHP-Based Chatroom Script
This easy to install, simple to handle, cross-browser compatible chat system comes with its own socket server. If you have a modern browser with frame support and JavaScript enabled, it makes use of these technologies; if you have an older browser, have JavaScript disabled, or even a text browser, you can still chat using this script. In contrary to many other PHP/MySQL webchats, this script can (but must not) be run using a non-forking socketserver to handle all message transport.

75) PHP Counter Hosting Script/Website
This script is a complete counter hosting tool. It lets you offer counter service to others from your site. Your members don’t need any PHP-support on their webserver, they just pass the required data through JavaScript to another script that is hosted on your server. It supports IP-check with timeout, show online-users, visitor-paths, download-count, multi-page count, email-notification, admin-mode to create/del users, request new password, visitors per day, search-function and a mailing list.

76) Perl Visitor Welcome Script
With this handy little perl script you can welcome your visitors depending on the time of day. The greeting text can be modified and is inserted by SSI. Features include the ability to greet the visitor depending upon the time of day, ability to insert the script by SSI, greeting words can be adapted freely, time offset between local time and server time can be adjusted.

77) Website Indexing and Searching Script
This sophisticated, powerful, versatile, customizable and effective site indexing/searching suite comes as a pair of distinct scripts. The indexer automatically scans and indexes a web site, and the search engine, a cgi script that serves search queries for keywords over the index, displays results pages in HTML, in a standard format including title, description and relevance ranking for each matching document.

78) PHP-Based Help Desk Script
With this script you can own your ticket based help desk system that allows you to completely manage and answer your clients questions with speed in ease. Messages are archived so you can refer back to questions when they are the related which will greatly reduce the time you have to spend managing your business.

79) Complete PHP Bug Tracking Script
This highly-usable PHP and MySQL based script is an easily deployable, web based bug tracker to aid in product bug tracking. Features include easy installation, platform independent, supports multiple projects and languages, emailing, searching and more. This script is a great thing to have if you are developing scripts or real-life projects and want a way for your users to submit bugs and for you to keep track.

80) Document Management System
This super script expertly programmed in PHP is a web based document management system designed to comply with ISO 17025 and OIE standard for document management. It features fine grained control of access to files, and automated install and upgrades.

81) Banner Management and Tracking System
This powerful script is a banner management and tracking system written in PHP; it can manage multiple banners (any size) per advertiser and allows you to view daily, overall and summary statistics plus send statistics to advertisers via email.

82) Web Form Generator Script
This script is an easy-to-use tool to create reliable and efficient web forms and the best part is that absolutely no programming of any sort is required and it has the ability to create up to 100 different form fields plus can add a variety of field types including text boxes, drop down selection and more.

83) Directory Indexer Written in PHP
 This PHP script makes a table that lists the files in a directory and lets you access the files and subdirectories. It includes searching, icons for each file type, an anti-leech feature, bandwidth limiting, access logging, and more.

84) Web-based Reservation System
A web-based reservation system that allows administered management ofreservations on any number of resources. Typical applications are room or machine reservation management.

85) PHP Online Project Management Script
You can now have online project management with team collaboration, user management, multiple access levels, tasks, projects, and time tracking, task change history, files approval tracking, notes, client project sites and more with this super useful script that can really help organize your business.

DOWNLOAD : http://rapidshare.com/files/166365223/85_php_scripts.rar

VISIT HTTP://WWW.JAZZGRAPHICS.ISGREAT.ORG TO SUPPORT US

JAZIB
http://www.articlesbase.com/software-articles/85-free-php-scripts-674255.html

I want to transfer all my song from my ipod onto this computer. How do i do it?

iPod to Mac OS Transfer is designed for Mac OS users to backup iPod to Computer, PC and iTunes, since iTunes blocks you transfer iPod music and other files on your Mac OS PC, this tool will help you backup entire iPod music, and photos library etc. You don’t need to worry about hard drive failure, a system crash with data loss, or other strange question. You get your music, videos, Photos to any iPod, PC, computer as you want.
http://www.dvd-video-converters.com/ipodconverter/ipod-to-computer-for-mac.html
Also, you can search some other ones:
http://www.ask.com

my desktop is Win XP and my laptop is Win 7.. I’m already able to browse the C drive but can’t go into desktop folder, (permission denied). I’ve tried adding my laptop user name as an administrator to desktop

You need to go to the Desktop folder, Right Click, choose Permissions, and allow other users access to the folder. Also, make sure both computers are in the same Workgroup.

I work in an office environment where most personal web content is blocked. I can avoid the filters by using remote desktop to log into my home PC for web browsing but I am concerned that my employer may still be able to track my browsing history.

Yes your employer can track your history via the internet using your remote desktop from work to your home pc. Your home pc as well will keep track of all that information. Business now days need to protect their assets and use Internet Authentication Services to track potential threats and create rules to allow\disallow content from infecting the work environment. The only way you have a work around is to create a virtual workspace because when you run a virtual machine within a machine, its as if the virtual machine doesn’t exist. I hope that made sense. Here is a software that you can find out more information from, but the rule of thumb is that if you can see it on your desktop, then your IS people can see it too.

http://www.vmware.com/products/workstation/

I have a desktop, and my house is really crappy, and very often we lose power, and have to flip the breaker to turn the power back on on that side of the house….

Well I was just wondering that if the power went out, while the computer was turned on, and you had to flip the breaker to get it back on, if it would harm the computer? It is plugged into a power strip, among other things… But yea, would it harm the computer?

If it does harm the computer, what would it harm? I heard that it could corrupt your data, sometimes ruint hardware, and even corrupt your operating system, or not allowing your computer to boot up. Are these true? Thanks in advance for your answers…

It quite possibly could if you have no surge protection on it. As far as your initially breaker problem, you have a fault in your house wiring. Most likely too much crap on one circuit. You need to look into this. A good electrician may be able to help you quite cheaply as he may be able to re-route some of the circuits in the breaker panel.

i do not have too much knowledge regarding processors and ram and their power behind a computer. i know that basically the bigger the better but since im on a tight budget and cant afford the whole package, which would be a faster and more powerful computer?

a quad core with 2 gb ram

or

a dual core with 4 gb ram

thanks!

For the processing power to work well with your system, you need RAM.
Also, how many GHz does the dual core have? The quad core?
Typically, the best choice in this equation would to be to go with the dual core.
If you’re trying to get more RAM, depending on what type you want, it isn’t that expensive. You could always buy some extra Gigabytes of RAM to put in.

Best of luck to you

Last year, Australians spent on average 251.5 days at the office. For many of us, that’s about 2012 hours at the desk, in front of at a carbon emitting computer or standing in front of a paper spitting, toner ejecting printer. It’s more important than ever to get your workplace in eco shape.

Australian offices use an estimated 1.4 million tonnes of paper every year. The average office document is printed 19 times. We throw out around 18 million used toner cartridges. Many of us leave our computers running and our office lights on into the wee hours of the night as we burn the midnight oil.

Here are some helpful cues for the cubicle, so you can enjoy those 2012 hours (or 1932 hours that are left) of 2009 in a more eco way.

1. Rethink ink and refill ink cartridges. A standard cartridge can be refilled up to four times before it needs to be replaced. Handy tip, get it filled as soon as you notice a decrease in the print quality, it keeps the heads from getting clogged up.

2. You can bring a cartridge recycling program into your office. Many of these programs collect toners and drums as well. Local outlets, such as the post office, will also collect them for reprocessing

3. Consider your superannuation. We all have it, but yours can make a difference towards the future. There are several super funds that have ethical or socially responsible options, such as Vic Super. This means that your superannuation money is only invested in companies that rate highly in terms of their environmental and social performance.

4. Ask to see your company’s environmental policy. If there isn’t one, then inquire as to why not, they might just be behind the green eight ball!

5. Relax and enjoy your lunch! If you’re buying food for lunch, eat it out instead of taking it back to your desk. It’ll save on packaging and keep your keyboard crumb free!

6. Look into starting an environmental committee at your work to affect change. It can be as simple as starting a recycling program or educating your colleagues.

7. Save paper and print double sided or re-use printer paper. Some printers can print double sided while others may require you to manually flip sheets over. Put a little reminder note on how to print double sided (Print side down!) to keep those little double sided feed-ins from happening.

8. Bring an indoor plant to work. They give your office a little green flair and give oxygen as wel as help filter indoor pollutants. Plants play an important role in keeping employees happy and relaxed while absorbing radiation from computers. Consider turning your office into an urban jungle!

9. Make sure your office switches off its lights at night, place a reminder notice above the switch. Switching on whole floors of lights for one worker burning the midnight oil is exceptionally wasteful. Consider using a desk lamp instead.

10. Power down computers and monitors. Standby power currently accounts for 10.7 per cent of average household power consumption which ends up as 6.5 million tonnes of CO2 emissions!

Find more green office tips, visit Australia’s leading directory for all things green including ideas for the green office.

Paige Green
http://www.articlesbase.com/business-ideas-articles/cues-for-the-cubicle-727471.html

By definition, a virus is a computer program that is able to copy itself and infect other computers. The first one, according to Wikipedia, was seen almost half a century ago. The Creeper virus was detected in ARPANET, a predecessor of the World Wide Web. This code is compared to their virus dictionaries and if a match is found, the antivirus program attempts to clean the suspicious part, without damaging the original data. Another method of fighting viruses is to monitor computer activity, also known as heuristic analysis. It was using the modem connection to replicate on other PCs and when it achieved its goal, it displayed the following message IM THE CREEPER: CATCH ME IF YOU CAN. Anti virus software is another kind of computer programs that appeared because of the need to disinfect computers from viruses. Reaper was the first of its kind and its aim was the Creeper virus. You can visit Some people said that they might have shared the same creator, but this was never proved.

Since the first antivirus program, viruses and methods to fight them evolved rapidly. Most of the times, the next step in evolution is done by computer viruses and antivirus creators struggle to fight back and invent new ways to clean those pesky bugs. The common approach of antivirus software is to scan files, memory or registries from your computer and detect malicious code. This code is compared to their virus dictionaries and if a match is found, the antivirus program attempts to clean the suspicious part, without damaging the original data. Another method of fighting viruses is to monitor computer activity, also known as heuristic analysis. This includes monitoring memory and ports traffic for any signs of infection. A modern approach is the so called sandbox method. It involves running the suspicious file into a simulated operating system and analyzing the results. No matter the method, if a virus is found, the antivirus first attempts to disinfect the file. If its unsuccessful, or go to the infected file is quarantined (isolated from other programs) or in worst case, deleted.

Its very important to have a reliable antivirus program installed because there can be viruses on a file you download, inside an email attachment or even a website can include some malicious code to infect your PC. Some of the programs that are out there and can do the task are free, but most of them require payment. This code is compared to their virus dictionaries and if a match is found, the antivirus program attempts to clean the suspicious part, without damaging the original data. Reaper was the first of its kind and its aim was the Creeper virus. Another method of fighting viruses is to monitor computer activity, also known as heuristic analysis. Almost all include updates of their viruses database, to make sure your PC is protected to the newest threats. AVG AntiVirus Free, BitDefender Free, Comodo AntiVirus and PC Tools AntiVirus Free Edition are only a couple of the free antivirus programs available on the Internet.

RAKESHMEET
http://www.articlesbase.com/software-articles/why-anti-virus-software-a-must-have-for-every-pc-673062.html

Dell printers are one of the most commonly purchased brands in the market. However, before you decide to purchase one yourself, even as part of a computer package, there are a few things you need to know about the equipment so you can make the right choice and end up with a printer that you are going to be happy with for years to come.

Dell Computers Not Really Dell

One of the most important things you should know about Dell printers are they are not manufactured by Dell. Instead, they are created by Lexmark. While Lexmark is also one of the biggest names in the printer industry, their products don’t always score well in terms of reliability. Basically, what happened is that Dell originally received its printers from a number of different printer manufacturers. About six years ago, they decided to become monogamous with Lexmark and began selling Lexmark printers that had been re-branded. Interestingly, just under one-fifth of all Lexmark printers are actually sold to Dell not directly to consumers.

Dell & Ink Issues

All inkjet printers are expensive to use for a lot of printing because of the cost of those replacement cartridges. However, Dell tends to be a bit higher because they sell two types of cartridges: one known as standard and the other called high-capacity. The price different is about 20% but the amount of ink in each printer ink cartridge is about 50% different. People who purchase replacement should always go for the high capacity cartridge because it will be a better deal in the long run. Also, if you are considering re-filling the cartridges you should know that Dell and Lexmark have added features to their cartridges to make it more difficult for the machines to recognize refilled ink.

Price of the Printer

In comparison to other similar printers, the price is affordable. When purchased with a computer package, you can sometimes even get the printer at no extra cost. Even when you do have to pay for the printer, you won’t have to pay very much. That’s one of the reasons why Dell printers are so popular with consumers.

Reliability

One of the biggest drawbacks of Dell computers is its reliability. While some printers on the market are known to be long-lasting, Dell is not one of them. Lexmark printers, as mentioned above, are well known for causing problems to their users. Even though the number of complaints about Dell units is not as plentiful as those for Lexmark units, they still are far from perfect. Plus, Dell has had some customer service issues in the past. Thankfully, the company has expressed their commitment to improving these situations.

John C. Arkin
http://www.articlesbase.com/hardware-articles/all-you-need-to-know-about-dell-printers-and-dell-cartridges-689275.html

Introduction to PLC’s

Programmable Logic Controllers

Bedford Associates, founded by Richard Morley introduced the first Programmable Logic Controller in 1968.  This PLC was known as the Modular Digital Controller from which the MODICON company derived its name.  The History of the PLC as told to Howard Hendricks by Dick Morley provides an interesting insight into the early development of the PLC.

 Schnieder Quantum PLC

Programmable Logic Controllers were developed to provide a replacement for large relay based control panels.  These systems were inflexible requiring major rewiring or replacement whenever the control sequence was to be changed.

The development of the micro processor from the mid 1970’s have allowed Programmable Logic Controllers to take on more complex tasks and larger functions as the speed of the processor increased.

Ladder Logic

PLC had to be maintainable by technicians and electrical personnel.  To support this the programming language of Ladder Logic was developed.  Ladder Logic is based on the relay and contact symbols technicians were used to through wiring diagrams of electrical control panels.

Until recently there has been no formal programming standard for PLC’s.  The introduction of the IEC 61131 Standard in 1998 provides a more formal approach to coding.  PLC Manufacturers have so far been slow on the uptake of the standard with partial implementation.  The SearchEng articleIEC 61131-3, a Standard for PLC Software by R.W. Lewis provides an introduction to the standard.

The documentation for early PLC Programs was either non existent or very poor, just providing simple addressing and basic comments, making large programs difficult to follow.  This has been greatly improved with the development of PLC Programming Packages.

SCADA and HMI

The early programmable logic controllers interfaced with the operator in much the same way as the relay control panel, via push-buttons and switches for control and lamps for indication.

The introduction of the Personal Computer (PC) in the 1980’s allowed for the development of a computer based interface to the operator, these where initially via simple Supervisory Control and Data Acquisition (SCADA) systems and more recently via Dedicated Operator Control Panels, known as Human Machine Interfaces (HMI).

The History of the PLC
as told to Howard Hendricks by Dick Morley

The following are some fables associated with the first ten years of the programmable controller business. These Fables may or may not have a basis of truth, but in general, they are the best that my Alzheimer-plagued memory can do at the moment. As has been often in other articles and reports, the startup of Modicon and the programmable controller industry as a whole is well documented. The programmable controller was detailed on New Year’s Day, 1968, and from hence till now, a slow steady growth has allowed the manufacturing and process control industries to take advantage of applications-oriented software.

The early days however, were not as straightforward nor as simple. We had some real problems in the early days of convincing people that a box of software, albeit cased in cast iron, could do the same thing as 50 feet of cabinets, associated relays and wiring. The process was indeed difficult, and deserves some of the stories that I hope the reader will be regaled with as he proceeds onward through the tortuous swamp of my mind.

One of my earliest recommendations was that the programmable controller, according to my own system architecture specification, did not need to go fast because I felt as though speed was not a criteria because it would go as fast as we needed it to. The initial machine, which was never delivered, only had 125 words of memory, and speed was not a criteria as mentioned earlier. You can imagine what happened! First, we immediately ran out of memory, and second, the machine was much too slow to perform any function anywhere near the relay response time. Relay response times exist on the order of 1/60th of a second, and the topology formed by many cabinets full of relays transformed to code is significantly more than 125 words. We expanded the memory to 1K and thence to 4K. At 4K, it stood the test of time for quite a while. Initially, marketing and memory sizes were sold in 1K, 2K, 3K, (?) and 4K. the 3K was obviously the 4K version with constrained address so that field expansion to 4K could easily be done.

The question of speed, in part, was part of the early designs. No interrupts were necessary because the external signal conditions were directly written onto memory without any supervisory requirements or “operating system of the conventional type. This allowed the processor to pay attention to solving logic rather than housekeeping the I/O. As a result, of course, the processor had to have significantly more processing power than normally associated with this size computer; and secondly, the system had to be made to run fast.

We increased the memory size, as mentioned above, but to get it to run fast, we had to break up the machine into three distinct components. Initially, the programmable controller was conceived of a processor board and a memory, and that the algorithmic and logical manipulation would be done in software. This approach was painfully slow, both on the generic “store bought computers, and other items.

We did, however, manage to substantially speed up the machine by making a third major component. This was called the logic solver. A logic solver board solved the dominant algorithms associated with solving ladder logic without the intervention and classical software approach of general-purpose processing. This meant that we ended up with three boards; memory, logic solver and processor. This single step allowed us to get the speed we needed in this application-specific computer to solve the perceptually simple problem of several cabinets full of relay wiring.

We had also assumed a modular approach to the programmable controller. In act, the name Modicon means MOdular DIgital CONtroller. The modularity, however, was soon abandoned because, as everyone knows, open architectures are no good. We instead had the marketing premise that a large footprint would contain within it the sets of problems we wished to solve. This meant that a buyer of programmable controllers could buy large numbers of the same units, and the software and hardware would be identical across a broad spectrum of applications in his factory. Service, maintenance and total life cost would be substantially lower than the perceived lower cost of an open architecture and modular expansion. Although at first, a supporter of the open architecture modular expansion, I soon became convinced by the marketplace, but this was folly.

We took one of our early units which was aimed at the machine tool industry because of my Bedford Associates consulting background, up to one of the early requesters of this equipment. This particular early requester was Byrant Chuck and Grinder in Springfield, Vermont. We took the machine up there, and it was heavy. This was the 084. The 084 was in the trunk of my old Pontiac, and since we needed help carrying it in, requested some of the people at Bryant to help us. We went out and opened the hood, and the first comment made by an outside viewer of the programmable controller said, “Thank God it,s not another pastel colored piece of sheet metal.

We can hypothesize from this particular comment that the ruggedness of the visual design was pleasing to him, and being human (as opposed to Martian), assumed that this same attitude went deep inside the construction of the machine in both the hardware and software. Indeed, this was the case, and the machine as a result, was built rugged, had no ON/OFF switch, had no fans, did not make any noise and had no wear out system.

To reminisce for a moment—in selecting the cores for the first memories, which in itself was a revolutionary step, we selected these cores and we applied Shannon,s Law. Shannon,s Law assumes that the signal-to-noise ratio is what makes signals good or bad. There are several ways to get the power from the signal-to-noise ratio; one is to code heavily, be triply redundant, and use lots and lots of error checking. There is another way, which is perfectly compatible with theory, which is to use lots of signal power in another domain. A nice switch, a car battery and a D-rated light bulb will work fairly well over a long time period.

Therefore, what we did was rather than going error checking, triply redundant and stuff, we got, and searched for and found high energy, large ferrite core memories that had lots on energy per bit. We still make the same assumption today. The energy per bit is extremely important—as Shannon,s theory said in his most famous 1948 paper, that the signal noise to power noise is what gives you transmission. the way we got signal power was to increase the energy per bit. This we felt was far more important than getting the energy per bit increased by means of doubly transmitting it. But I digress. Bryant Chuck and Grinder put it in, and liked the equipment so much that they never bought one. They in turn thought it was a good idea, and as many did at that time, tried to evolve their own.

One of our first major customers, however, was Landis in Landis, PA. We flew the equipment down in a private aircraft, and with apprehension because we were late (as usual), brought the equipment into Landis. In doing so, we tripped over the threshold. The equipment went KA-RASH onto the floor! Without much chagrin, we picked the equipment up, trundled it in. hooked it up, and low and behold, it worked quite well.

Now, Landis was pleased and surprised. They were pleased because it worked, but they were most pleasantly surprised—not because the equipment worked—but because the guys from Modicon fully expected the equipment to work in spite of it being dropped. In other words, the people from Modicon weren,t nervous about the fact that it fell on the floor over the threshold.

Landis subsequently took and wrapped welding coils of wire around the machine to induce electro-magnetic noise to see if they could make it fail. We had them there! We used to test the programmable controllers with a Teslar coil that struck a quarter inch to half-inch arch anywhere on the system, and the programmable controller still had to continue to run. There was significant strangeness with respect to the programmable controller. For example, it had no ON/OFF switch. It had no means to load software. It had no fans. It ran cool. It could survive bad, physical and thermal environments. It was not computer industry standard. There were many things that were most difficult in the acceptance of the programmable controller, and early acceptance was most difficult indeed.

Our sales in the first four years were abysmal. Early innovators such as Landers and General Motors were, of course, heroes to our eyes, but they would buy small numbers of units and then test them in the field before they committed themselves later on. We had one customer in the utilities business that took them approximately six to seven years to make a decision to but the first one.

We never really sold any programmable controllers into the intended market which was machine tool control such as lathes, grinders and stuff, but we did, as luck would have it, stumble across the transfer line market which was and still is the mainstay, long-term market for the application of programmable controllers. Discreet parts manufacturing in an automatic environment, i.e., mass production, continues to be, and probably will be for the future, the mainstay of the programmable controller industry.

Some of the more interesting stories center around the personalities and experiences as opposed to the programmable controller. Modicon,s third president (or fourth, if you count my two-week stint) was Don Kramer. When Don Kramer was chosen as president, we decided to go out and celebrate at the Lanum Club in Andover. At the time, we felt we should celebrate over both martinis and food. As we were leaving the shop for the Lanum Club, Don made the aside comment that “the place is dingy and needs a paint job. As we were leaving, I mentioned to Don that as president you have to change what you say, and not be very open—you have to be a little careful about what you say because employees, customers, and boards of directors tend to take what you say as truth. Rather than listen to the meaning, they listen to the literal statements, and one must be careful. We went over to the Lanum Club and had a nice glowing two hours of discussion, food, and drink. Coming back, as we entered the Modicon lobby, we noticed that there was scaffolding about and people were painting. We went over and asked Lou as to why these people are painting since, at the time, we don,t have any money. Who ordered this paint job? And Lou looked Don Kramer straight in the eye, and said, “Why you did, Mr. Kramer. Nuff said.

As has been mentioned many times, your author, that,s me—Dick Morley—is supposed to be the inventor of the programmable controller. This is at best, partially true. The thing that made the Modicon company and the programmable controller really take off was not the 084, but the 184. The 184 was done in design cycle by Michael Greenberg, one of the best engineers I have ever met. He, and Lee Rousseau, president and marketeer, came up with a specification and a design that revolutionized the automation business. they built the 184 over the objections of yours truly. I was a purist and felt that all those bells and whistles and stuff weren,t “pure, and somehow they were contaminating my “glorious design, Dead wrong again, Morley! they were specifically right on! the 184 was a walloping success, and it—not the 084, not the invention of the programmable controller—but a product designed to meet the needs of the marketplace and the customer, called the 184, took off and made Modicon and the programmable controller the company and industry it is today. My compliments to the two chefs—Lee Rousseau and Mike Greenberg.

The issue of quality in programmable controllers is a story that is normally taken for granted. The gentle reader must remember that our engineering people came from the computer industry where reliability in those days was a phantom—a phantom of design, a phantom of cost. People felt that reliability was something other people did, and that if we only could deliver faster computers, even if they didn,t work, everything would be fine.

When the programmable controller was designed, it was designed in to be reliable. We used lots of energy per information bit by utilizing D-rated components, large memory ferrite cores, relatively stable and large etchings on printed circuit boards, totally enclosed systems and conductive cooling. No fans were used, and outside air was not allowed to enter the system for fear of contamination and corrosion. Mentally, we had imagined the programmable controller being underneath a truck, in the open, and being driven around—driven around in Texas, driven around in Alaska. Under those circumstances, we anted it to survive. The other requirement was that it stood on a pole helping run an utility or a microwave station which was not climate controlled, and not serviced at all. Under those circumstances, would it work for the years that it was intended to be? Could it be walled in? Could it be bolted in a system that was expected to last 20 years?

The humorous side of this is though we did all those designs and very carefully tried to make this system as intrinsically reliable as we could, not by redundancy, but by building well. In other words, it was designed to be built, it was designed to be designed, and it was designed to be reliable. We, however, as engineers, didn,t understand the accountants and manufacturing. those two have their grail, shipments by the end of the month. As far as we could ascertain at the time, shipments were made independent of quality and independent of whether or not the system ran.

In the early days of the programmable controller and Modicon, even though I wasn,t a direct employee and an owner, I would give out my home phone number to many of our critical customers so that if they had a problem, they could call me directly. Several calls indicated that when we shipped near the end of the month, let’s say October 34th, that the equipment would not run; and secondly, when they opened the box and took the machine apart, cards were missing, bolts were on the bottom of the cabinetry, and some of the cards were not fully inserted. In other words, to make the end of the month was much more important than to deliver equipment that ran. to put it mildly, we were pissed! How do we as engineers maintain quality without continual surveillance which is most difficult for the design and entrepreneurial mind set. What we did was specify and design “blue boxes. These were cabinetries that the system had to operate in and run continuously for a minimum of 24 hours, under load, and under varying conditions. The box was built out of plywood, but its primary intention was to heat cycle the programmable controller under various input/output loads. We also ran, as a specification, that a Tesla coil was to be used on the programmable controller, and that vibration and thumping with a hammer (rubber) would be part of the specification.

This may seem unscientific to many of you, but let us assume that you try to get your equipment to run while somebody purposely tries to destroy it with a rubber hammer or spark coil that he can put anywhere on the system. Remember, your intention is to make the processor stop. That combination significantly depressed those monthly shipments during the first period. As a result of that, however, the message got through. Not only did we build ovens and tests, and pay attention to heat and spark and RF emissions, we would run the system continuously even in the shipping crate to get the maximum number of pre-custom hours we could. It was important to us that we found the mistakes and not the customer and his secondary customer.

The language itself, ladder lister, bears some discussion. This particular language was not the invention of Modicon. We hypothesize that the language is very old, and originated in Germany to describe relay circuitry. If one looks at ladder lister, it has been our technical community for so long, we somehow think those little symboligies actually look like relays. In fact, it,s a mnemonic form of rule-based language, very modern and very high level, but designed in a Darwinian fashion over a period of many decades.

The ladder logic construct, “If… Then… is a very powerful construct used today in expert systems and other rule-based languages. The symbology, allowing normally open and normally closed situations as well as parallel and serial representation, was used for many decades before the invention of the programmable controller. I have worked on machines where the number of C-size and D-size prints were hung in special racks, and would be up to three feet thick worth of documentation on those drawing sets.

The name ladder comes from the fact that on the right-hand of the drawing is one power rail and the left-hand side is the other power rail; and in between in a horizontal fashion, is the statement or sequential connection of logical elements which we call relays or relay logic. The initial 084 had only logic in its functionality, and as a result, was marginal. In other words, all we did was replace relays rather than enhance the functionality by a factor of ten which is the entrepreneurial rule. Immediately, of course, based on customer response and our own frustrations, we put thing in the ladder listing language such as addition, multiplication, subtraction, and other functionalities that went far beyond relay capability and entered the realm of mathematics and set theory. This was still not sufficient, however, and we needed some way to make a “call to a “subroutine using ladder lister symbology and representation.

A software engineer, Chuck Schelberg, and myself were in the conference room one day trying to ascertain how we could make a generic call to functionalities that far exceeded the relay symbology and representation, and came up with the “DX function. This function was a block function that would be an element on the ladder logic representation that could perform many functionalities including arrays, motor drive functions, servo functions, extended mathematical functions, PID loops, ad nauseam. We felt there would be an occasional representation and use of these functionalities, and that not much had to be done to the programmable controller other than to modify the software. Wrong again!

The first customer that took delivery of a programmable controller utilizing the DX function, had a capability to be predictable and operate in real time. The RUN light went out, and the time to execute a scan or complete transformation of the ladder logic went far beyond the time allowable. Every single line had a DX function on it. Again we learned that when you enhance functionality, people use it all. I have never designed a computer that had too much memory. I,ve only designed computers that have too little memory. The same thing applies to any other functionality. Conventional wisdom seems to think that price/performance depends on only one thing—price—when, in fact, my experience has been that the customer cares little about price.

This price/performance tirade being over, one of the lessons we learned is that the customer wants functionality over the entire life cycle cost installation of the job. the customer also wants ease of installation, to have some fun, and to be proud of the work he does. After he,s finished, he never wants to come back.. The equipment should work as installed and as based. At one time, the programmable controller meantime before failure in the field was 50,000 hours. This is far in excess of almost any other type of electronic or control equipment.

The concept of languages and high-level languages is important. The programmable controller, as it evolved, began to request more and more power, and more and more memory. The memories continually went up as well as power. It is estimated that at one time, in the mid-1970s, that the programmable controller had the equivalent of two MIPS processor and 128 kilobytes of memory, which at that time was a significantly powered minicomputer capability. Why? High-level languages require power to run them. If we take the equivalent of the ladder lister statement “If… Then…, the high-level language as represented here, requires a substantial amount of interpretive compiler, if you will, generation of underlying code. In other words, this statement spawns significant underlying code that must be run quickly, reliably, and contain within it, all aspects of resource allocation and operations resource. The higher level the language, the more powerful the processor apparently has to be in order to run the language. Ladder lister is a high-level rule-based language which, until now, we haven,t talked much about in these terms. Our customers treated the programmable controller as a box of relays, and well they should. Language theory is neither necessary not desirable for most of the customers to know. The customers, instead, understand their problem, and are indeed much smarter than the design engineers because the dimensions of their problem far exceed the relatively simple problem of designing a computer software system and language. Ladder lister requires high performance which is one of the reasons it has difficulty running on the personal computer even of today

INTRODUCTION TO SCADA

SCADA is the abbreviation for Supervisory Control And Data Acquisition. It generally refers to an industrial control system: a computer system monitoring and controlling a process. The process can be industrial, infrastructure or facility based as described below:

            Industrial processes include those of manufacturing, production, power generation, fabrication, and refining, and may run in continuous, batch, repetitive, or discrete modes.

            Infrastructure processes may be public or private, and include water treatment and distribution, wastewater collection and treatment,  oil and gas pipelines, electrical power transmission and distribution, and large communication systems.

            Facility processes occur both in public facilities and private ones, including buildings, airports, ships, and space stations. They monitor and control HVAC, access, and energy consumption.

A SCADA System usually consists of the following subsystems:

            A Human-Machine Interface or HMI is the apparatus which presents process data to a human operator, and through which the human operator monitors and controls the process.

            A supervisory (computer) system, gathering (acquiring) data on the process and sending commands (control) to the process

            Remote Terminal Units (RTUs) connecting to sensors in the process, converting sensor signals to digital data and sending digital data to the supervisory system.

            Communication infrastructure connecting the supervisory system to the Remote Terminals Units

There is, in several industries, considerable confusion over the differences between SCADA systems and Distributed control systems (DCS). Generally speaking, a SCADA system usually refers to a system that coordinates, but does not control processes in real time. The discussion on real-time control is muddied somewhat by newer telecommunications technology, enabling reliable, low latency, high speed communications over wide areas. Most differences between SCADA and Distributed control system DCS are culturally determined and can usually be ignored. As communication infrastructures with higher capacity become available, the difference between SCADA and DCS will fade.

 Systems concepts

The term SCADA usually refers to centralized systems which monitor and control entire sites, or complexes of systems spread out over large areas (anything between an industrial plant and a country). Most control actions are performed automatically by remote terminals units (”RTUs”) or by programmable logic controllers (”PLCs”). Host control functions are usually restricted to basic overriding or supervisory level intervention. For example, a PLC may control the flow of cooling water through part of an industrial process, but the SCADA system may allow operators to change the set points for the flow, and enable alarm conditions, such as loss of flow and high temperature, to be displayed and recorded. The feedback control loop passes through the RTU or PLC, while the SCADA system monitors the overall performance of the loop.

Data acquistion begins at the RTU or PLC level and includes meter readings and equipment status reports that are communicated to SCADA as required. Data is then compiled and formatted in such a way that a control room operator using the HMI can make supervisory decisions to adjust or override normal RTU (PLC) controls. Data may also be fed to a Historian, often built on a commodity Database Management System, to allow trending and other analytical auditing.

SCADA systems typically implement a distributed database, commonly referred to as a tag database, which contains data elements called tags or points. A point represents a single input or output value monitored or controlled by the system. Points can be either “hard” or “soft”. A hard point represents an actual input or output within the system, while a soft point results from logic and math operations applied to other points. (Most implementations conceptually remove the distinction by making every property a “soft” point expression, which may, in the simplest case, equal a single hard point.) Points are normally stored as value-timestamp pairs: a value, and the timestamp when it was recorded or calculated. A series of value-timestamp pairs gives the history of that point. It’s also common to store additional metadata with tags, such as the path to a field device or PLC register, design time comments, and alarm information.

Human Machine Interface

A Human-Machine Interface or HMI is the apparatus which presents process data to a human operator, and through which the human operator controls the process.

An HMI is usually linked to the SCADA system’s databases and software programs, to provide trending, diagnostic data, and management information such as scheduled maintenance procedures, logistic information, detailed schematics for a particular sensor or machine, and expert-system troubleshooting guides.

The HMI system usually presents the information to the operating personnel graphically, in the form of a mimic diagram. This means that the operator can see a schematic representation of the plant being controlled. For example, a picture of a pump connected to a pipe can show the operator that the pump is running and how much fluid it is pumping through the pipe at the moment. The operator can then switch the pump off. The HMI software will show the flow rate of the fluid in the pipe decrease in real time. Mimic diagrams may consist of line graphics and schematic symbols to represent process elements, or may consist of digital photographs of the process equipment overlain with animated symbols.

The HMI package for the SCADA system typically includes a drawing program that the operators or system maintenance personnel use to change the way these points are represented in the interface. These representations can be as simple as an on-screen traffic light, which represents the state of an actual traffic light in the field, or as complex as a multi-projector display representing the position of all of the elevators in a skyscraper or all of the trains on a railway.

An important part of most SCADA implementations are alarms. An alarm is a digital status point that has either the value NORMAL or ALARM. Alarms can be created in such a way that when their requirements are met, they are activated. An example of an alarm is the “fuel tank empty” light in a car. The SCADA operator’s attention is drawn to the part of the system requiring attention by the alarm. Emails and text messages are often sent along with an alarm activation alerting managers along with the SCADA operator.

Hardware solutions

SCADA solutions often have Distributed Control System (DCS) components. Use of “smart” RTUs or PLCs, which are capable of autonomously executing simple logic processes without involving the master computer, is increasing. A functional block programming language, IEC 61131-3, is frequently used to create programs which run on these RTUs and PLCs. Unlike a procedural language such as the C programming language or FORTRAN, IEC 61131-3 has minimal training requirements by virtue of resembling historic physical control arrays. This allows SCADA system engineers to perform both the design and implementation of a program to be executed on an RTU or PLC. Since about 1998, virtually all major PLC manufacturers have offered integrated HMI/SCADA systems, many of them using open and non-proprietary communications protocols. Numerous specialized third-party HMI/SCADA packages, offering built-in compatibility with most major PLCs, have also entered the market, allowing mechanical engineers, electrical engineers and technicians to configure HMIs themselves, without the need for a custom-made program written by a software developer.

Remote Terminal Unit (RTU)

The RTU connects to physical equipment. Typically, an RTU converts the electrical signals from the equipment to digital values such as the open/closed status from a switch or a valve, or measurements such as pressure, flow, voltage or current. By converting digital setpoints to electrical signals and sending these electrical signals out to equipment the RTU can control equipment, such as opening or closing a switch or a valve, or setting the speed of a pump.

Quality SCADA RTUs have these characteristics:

            Data Networking capability

            Data Reliability

            Data Security.

Supervisory Station

The term “Supervisory Station” refers to the servers and software responsible for communicating with the field equipment (RTUs, PLCs, etc), and then to the HMI software running on workstations in the control room, or elsewhere. In smaller SCADA systems, the master station may be composed of a single PC. In larger SCADA systems, the master station may include multiple servers, distributed software applications, and disaster recovery sites. To increase the integrity of the system the multiple servers will often be configured in a dual-redundant or hot-standby formation providing continuous control and monitoring in the event of a server failure.

Initially, more “open” platforms such as Linux were not as widely used due to the highly dynamic development environment and because a SCADA customer that was able to afford the field hardware and devices to be controlled could usually also purchase UNIX or OpenVMS licenses. Today, all major operating systems are used for both master station servers and HMI workstations.

 Operational philosophy

For some installations, the costs that would result from the control system failing is extremely high. Possibly even lives could be lost. Hardware for some SCADA systems is ruggedized to withstand temperature, vibration, and voltage extremes, but in most critical installations reliability is enhanced by having redundant hardware and communications channels, up to the point of having multiple fully equipped control centres. A failing part can be quickly identified and its functionality automatically taken over by backup hardware. A failed part can often be replaced without interrupting the process. The reliability of such systems can be calculated statistically and is stated as the mean time to failure, which is a variant of mean time between failures. The calculated mean time to failure of such high reliability systems can be on the order of centuries.

 Communication infrastructure and methods

SCADA systems have traditionally used combinations of radio and direct serial or modem connections to meet communication requirements, although Ethernet and IP over SONET / SDH is also frequently used at large sites such as railways and power stations. The remote management or monitoring function of a SCADA system is often referred to as telemetry.

This has also come under threat with some customers wanting SCADA data to travel over their pre-established corporate networks or to share the network with other applications. The legacy of the early low-bandwidth protocols remains, though. SCADA protocols are designed to be very compact and many are designed to send information to the master station only when the master station polls the RTU. Typical legacy SCADA protocols include Modbus RTU, RP-570, Profibus and Conitel. These communication protocols are all SCADA-vendor specific but are widely adopted and used. Standard protocols are IEC 60870-5-101 or 104, IEC 61850 and DNP3. These communication protocols are standardized and recognized by all major SCADA vendors. Many of these protocols now contain extensions to operate over TCP/IP. It is good security engineering practice to avoid connecting SCADA systems to the Internet so the attack surface is reduced.

RTUs and other automatic controller devices were being developed before the advent of industry wide standards for interoperability. The result is that developers and their management created a multitude of control protocols. Among the larger vendors, there was also the incentive to create their own protocol to “lock in” their customer base. A list of automation protocols is being compiled here.

Recently, OLE for Process Control (OPC) has become a widely accepted solution for intercommunicating different hardware and software, allowing communication even between devices originally not intended to be part of an industrial network.

 Trends in SCADA

There is a trend for PLC and HMI/SCADA software to be more “mix-and-match”. In the mid 1990s, the typical DAQ I/O manufacturer supplied equipment that communicated using proprietary protocols over a suitable-distance carrier like RS-485. End users who invested in a particular vendor’s hardware solution often found themselves restricted to a limited choice of equipment when requirements changed (e.g. system expansions or performance improvement). To mitigate such problems, open communication protocols such as IEC870-5-101/104 and DNP 3.0 (serial and over IP) became increasingly popular among SCADA equipment manufacturers and solution providers alike. Open architecture SCADA systems enabled users to mix-and-match products from different vendors to develop solutions that were better than those that could be achieved when restricted to a single vendor’s product offering.

Towards the late 1990s, the shift towards open communications continued with individual I/O manufacturers as well, who adopted open message structures such as Modbus RTU and Modbus ASCII (originally both developed by Modicon) over RS-485. By 2000, most I/O makers offered completely open interfacing such as Modbus TCP over Ethernet and IP.

SCADA systems are coming in line with standard networking technologies. Ethernet and TCP/IP based protocols are replacing the older proprietary standards. Although certain characteristics of frame-based network communication technology (determinism, synchronization, protocol selection, environment suitability) have restricted the adoption of Ethernet in a few specialized applications, the vast majority of markets have accepted Ethernet networks for HMI/SCADA.

“Next generation” protocols such as OPC-UA, Wonderware’s SuiteLink, GE Fanuc’s Proficy and Rockwell Automation’s FactoryTalk, take advantage of XML, web services and other modern web technologies, making them more easily IT supportable.

With the emergence of software as a service in the broader software industry, a few vendors have begun offering application specific SCADA systems hosted on remote platforms over the Internet, for example, PumpView by MultiTrode. This removes the need to install and commission systems at the end-user’s facility and takes advantage of security features already available in Internet technology, VPNs and SSL. Some concerns include security, Internet connection reliability, and latency.

SCADA systems are becoming increasingly ubiquitous. Thin clients, web portals, and web based products are gaining popularity with most major vendors. The increased convenience of end users viewing their processes remotely introduces security considerations.

 Security issues

The move from proprietary technologies to more standardized and open solutions together with the increased number of connections between SCADA systems and office networks and the Internet has made them more vulnerable to attacks. Consequently, the security of SCADA-based systems has come into question as they are increasingly seen as extremely vulnerable to cyberwarfare/cyberterrorism attacks.

In particular, security researchers are concerned about:

            the lack of concern about security and authentication in the design, deployment and operation of existing SCADA networks

            the mistaken belief that SCADA systems have the benefit of security through obscurity through the use of specialized protocols and proprietary interfaces

            the mistaken belief that SCADA networks are secure because they are purportedly physically secured

            the mistaken belief that SCADA networks are secure because they are supposedly disconnected from the Internet

Because of the mission-critical nature of a large number of SCADA systems, such attacks could, in a worst case scenario, cause massive financial losses through loss of data or actual physical destruction, misuse or theft, even loss of life, either directly or indirectly. Whether such concerns will cause a move away from the use of existing SCADA systems for mission-critical applications towards more secure architectures and configurations remains to be seen, given that at least some influential people in corporate and governmental circles believe that the benefits and lower initial costs of SCADA based systems still outweigh potential costs and risks] Recently, multiple security vendors, such as Byres Security, Inc., Industrial Defender Inc., Check Point and Innominate, and N-Dimension Solutions have begun to address these risks by developing lines of specialized industrial firewall and VPN solutions for TCP/IP-based SCADA networks. The problem according to Eric Byres, CEO of Byres Security, is that “while many infrastructure organizations are doing good work, others are falling behind. When you have this diversity of effort, you are only as effective as your weakest link.

Also, the ISA Security Compliance Institute (ISCI) is emerging to formalize SCADA security testing starting as soon as 2009. ISCI is conceptually similar to private testing and certification that has been performed by vendors since 2007, such as the Achilles certification program from Wurldtech Security Technologies, Inc. and MUSIC certification from Mu Security,  Inc. Eventually, standards being defined by ISA SP99 WG4 will supersede these initial industry consortia efforts, but probably not before 2011.

N.Sankari
http://www.articlesbase.com/electronics-articles/introduction-to-plc-and-scada-679975.html