Old Diskmags Unreadable:
A Great Loss?

By EP / CosmiK

This article is a reply to the article "Old PC Diskmags - Lost for Ever?" by Adok/Hugi, which was published in Hugi 28.

Well, the scene underwent something like a cultural evolution and so losing a part of the scene's productions is like losing a part of its history. With losing old diskmags we lose a part of our past, that's a bit annoying. Why don't these diskmags work now? Have you used the compatibility tabs in the properties screen of the executable? If yes and it doesn't help, then read more about the bugs, their sources and their fixes:

In fact a lots of problems occur due to the fact that nowadays all soundcards are different from those used in the past. The ISA bus has vanished from the PC mainboards and sound drivers that used to access the soundcard using the ISA bus crash the newer systems. To help solve this kind of problem there is a solution which can be downloaded at http://ntvdm.cjb.net/; it's called VDMsound-2.0.4. This program emulates an ISA card, thus all the old ISA IRQ, DMA and PORT are present for the diskmags playing routines. Hence, every modern soundcard can play and run software based on ISA soundcard code. The emulated soundcards are SoundBlaster and Adlib. That means all GUS-only products will not work using the VDMSound, but almost old stuff done under DOS was coded to use different soundcards and especially both SoundBlaster and GUS. Another way to get all the DOS-based programs which have a problem with the soundcard to run is to rewrite the DOS Sound drivers to let them handle the new cards or try to configure them not to play any sound.

Another problem with computers of these days is their speeds. We have machines (such as P4 II, 6 GHz) running 15 times faster than a P166 and so code badly written to run on a P166 will crash on a 2.6GHz machine. So what to do? Slow your PC down!!! SlowMo, which is sadly commercial software, can help resolve this problem. The problem comes from synchro routines which don't wait using a timer independent of the mainboard clock speed. The way to make all the diskmags run on today's PC? Patch the diskmag executables using a patch for the timer unit of Pascal and such high level languages. Yes, the bugs come from the code units used by Pascal and other high level languages.

The asm buggued code used in old diskmags needs one thing: patches by skilled coders. In an hour, all diskmags can be fixed for ever: five minutes to find the gulty routines in the several diskmags series. Almost all diskmags of one series have the same or approximately the same code. Five minutes to code the new routines and 50 minutes to patchs all the different diskmags.

EP / CosmiK