Edit/Debug Pacioli 2000 for Y2K Compatibility

[mdp_mason]

Hi,

Not sure if this belongs here or on the tech support side. I am looking for advice on learning to debug DOS programs. In particular I would love to patch some old accounting software so that it can handle dates from the 2000's and allow transactions past 1999. It uses two digit years (I'd like to make this bullet proof by going to 4 digits) and has a limitation on posting transactions only between 1980 and 1999.

Before I get into any more details, is this a lost cause/terrible way to learn how to debug and understand old programs? I have beginner experience in python and I have barely dabbled into assembly. The only thing I seem to understand very well is bash from years of Linux use.

If this isn't a totally dead idea, what programs would everyone recommend to do so? If possible I'd like to run this on my 5170 (PC DOS 7). If its a matter of availably or convince emulation is a welcome suggestion as well. I tried running debug and it works fine, problem is me not understanding the HEX codes and where would these date controls be stored.

Looking forward to suggestions!

 

[Ruud]

In the first place, you need a bit more professional tool than DEBUG and I would suggest Borland Turbo Debugger. But I must warn you: if the program is more than a few KB, it will be a hell of a job. Debugging undocumented C or Pascal code can be very difficult but debugging undocumented ML code can be hell on earth. With C and Pascal code the name of the variables, constants etc. can give you a good hint but a numerical address as variable won't tell you anything.
I disassembled quite some BIOSes of various XT clones so I have some experience. But in this case I have a general Idea what will happen but even then it is difficult. The BIOSes of various Commodore PCs gave me the most trouble.

I wish you all the luck and I really, really hope that there are others who can give you more, and hopefully, better ideas

 

[mdp_mason]

Thank you for the advice!

Yeah I'm not gonna hold out toooo much hope this will be successful but I'll treat it as a learning experience. I am highly motivated (and stubborn enough) to get some form of accounting software to run with today's dates on real vintage hardware. I think with how old some of this is and many of the companies going under later, the chances of finding software out of the box or old patches are nil to none. For this one I know it was patched by the developer from what I've read but no luck on finding said patch. So why not try it myself and see if I can do anything.

I have a copy of borland C++ I can install, I think it comes with the debugger. Later today I'll grab raw write for DOS and see if I can write the 5.25" images to my floppies.