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ArticlesConverting Your Old DOS Based Application to Windows
custom software design

Back in the late 1980's and early 1990's, computing was a lot simpler. You did not have the concept of online, the internet, or even relying solely on Windows operating system. You had a basic machine, possible an IBM AS400 or similar type ... or you were running Windows 3.1, Windows NT 3.5 or even MS-DOS as the main operating system. Pretty much all business software back then was designed to work for MS-DOS. That is the way it used to be.

Well, we are now up to Windows 7 and moving fast but a lot of businesses still use their DOS application in order to run their business. Why? ...because if it ain't broke, don't fix it... and you know what, they are right! The only problem is that one day, the hardware on the computer or software will eventually break and then what? Then you try to move the program on a new computer (which will probably have Windows 7 by now), there is a good chance some of the features of the old program on that new computer will not work.
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Whether it is a printer problem, database connection problem or networking problem, the business owner will eventually be forced to overhaul and convert that DOS program to Windows or go out and buy a new program and restart from scratch.

Starting from scratch may not be an option for some companies. In fact, there may be years of data that you simply cannot throw away and start over. So what is the solution? Hire someone to come in, evaluate the old program, see what can be done and if all is convertible, then go ahead and do it. Well yes, this is what we do. We have worked in these types of situations for a long time and continue to do so. But let's discuss briefly what kind of programming language and database your old application may already be created in.

Back then, a popular database called dBase IV was very big and a lot of applications use this for their database. dBase IV was the first widely used database management system (DBMS) for microcomputers, published by Ashton-Tate for CP/M, and later on the Apple II, Apple Macintosh, UNIX, and IBM PC. It became one of the best-selling software titles for a number of years. dBase IV was not successfully ported to Microsoft Windows for some time, and gradually lost market share to competitors such as Paradox, Clipper, FoxPro, and Microsoft Access. FoxPro use a file called a DBF file to store data, which is basically the same as dBase IV. One thing I should mention about dBase IV, is that it was a very stable and reliable that a lot of programming languages like Clipper and FoxPro used to develop around.

Well, now back to the problem at hand. How can we make things right?

There are several things that need to be done in order to convert the application.

#1. The ability to read and convert the old database to something newer: There are a lot of software tools that allow you to read an old database like dBase IV and FoxPro. If this is successfully done, then it will take quite a bit of work but at least the data can be converted to today's database like MS Access 2007. But, some DOS programs use a proprietary database and if that is the case, it may be a lot harder if not impossible to retrieve the data. In this case, the only thing you have to rely on is the screens to figure what fields the database had. This process is very important and is a key part in first evaluating the scope of the job.

#2. Screen Design/Look and Feel: This step involves recreating the screen using a Windows programming language like Visual Basic.Net by re-creating all the screens with the same look and feel that the DOS application had. This is simply done by obtaining screen shots (or a demo) of what the DOS program did. That way, we can step by step create a new screen almost exactly as the old one.

#3. Converting the Code: This part is the meat and potatoes of the job and may take quite a bit of work. Although, computer memory wasn't much and disk space was very limited, a DOS program can use quite a bit of space. There are also the formulas specific to your business. These are very important and include field calculations, rate calculations, etc... These are going to have be spelled out and listed so that everything is accounted for during the conversion process. These formulas can either be taken directly from the old FoxPro/Clipper code or upon consulting with the business owner will need to be re-created. The latter would of course require more work than the former.

#4. Converting the Reports: A software application most likely has reports. Without report, you won't know how your business is doing by using your trusted DOS software. These reports are used to produce a hard copy (printout) of specific information that you request based on criteria that you are looking for. These text based reports will also need to be converted to Windows using today's popular fonts and colors to get the best representation of what data you are reporting on.

#5 Converting Extras: This involves special printer attachments (like label/check printers), modem connections (like for direct calling software), and/or any other feature that the old software did. This section would probably be the last thing that needs to be addressed but yet is still an integral part of making the software work in today's environment.

Once, these steps are successfully taken, you now have a Windows application that works just like the old one did. The idea is to make it compatible but keep it is close and as simple as possible so users do not have to re-learn the ins and outs of the program.

*Please Note: There is no simple way of "converting" a DOS program to Windows. There is no magical software to do this. We are able to convert and maintain your data but the software needs to be redesigned in Windows. Just like when you first bought your DOS program there was no simple way to get your paper files on the computer.

I hope this article provided some basic information on what needs to be done and understand the conversion and/or rebuilding work that may be involved when doing this. This is what we specialize in. For more information, please contact us, with questions, an evaluation and/or a quote. Prices depend of course the size and scope of the existing program.

Your Feedback
11/28/2017 - I have a DBASE III Plus Program Compiled in Clipper running on DOS. I want to convert it to a Windows based program. I was told MS Access or SQL are the preferred programs for this. I already tried going with a programmer who told me he would use Visual Basic, but it turns out he didnt know DBase as well as he should have. He wanted me to adapt to him and nearly write the program all over again (I already went thru this in 1982). Can anyone help? Is it expensive? - Art
04/20/2014 - I love when people comment on others spelling mistakes and makes one of their own! Priceless!! - Venessa
06/25/2012 - Good article.I still do some support with a DOS program, but not as much these days as most of my clients have converted to Windows/web based.FYI, spelling error on point #4. hese should be These. (People wanting conversion work, don like to see errors), just wanted to help you out here, as that would be a turn off for me if I needed your services.Thank you for the article, it is very informative! - Mark
06/12/2011 - hi ,how can i do this converting ?please help me .thank you very much - saeed