Problems with New Dell Systems Video, Can't Download DOS Font

This is a bit of an obscure problem, but I'm hoping someone here can help. I use a legacy DOS application (the APL computer language) that requires special characters. These are downloaded into the video system by a TSR program run before the main executable is loaded. This process has worked fine on thousand of different computers for almost 20 years.

Just last week, I bought a new Dell Dimension E310 at home for my girls, and I got a new Dell Optiplex GX620 at work. Simultaneously, someone posted to comp.lang.apl that they couldn't get the APL characters to work on a Dell Dimension 4700 (vintage unknown). Well, it turns out that neither of the two new Dells I have will work either. The two machines I use have very different video systems. My old machine at work was a Dell (forget the model), with a dual video card, and it worked fine with Windows 2000. All the other systems are running XP Pro. I have a 1 year old IBM laptop at home that's running XP Pro, and it works just fine, so I don't think it's the OS.

It's possible that the new video adapters don't bother to support this feature, even though it's been part of the VESA standard for a very long time. However, the fact that all three machines are Dells, and with at least two different video hardware setups, makes me wonder if Dell has done something odd in the BIOS (for example) that might be causing this problem.

Any ideas or suggestions would be approciated. Abandoning APL isn't an option (yet). The reason that I need the DOS version is to finish porting the code to a newer Windows APL.

Thanks!

Doug White