Hi everyone,

I just stumbled upon a little problem while tinkering with 16-Bit OS/2.
As you may know, the DOS compatibility box, better known as the "penalty box", provides a single DOS "VM" (not really, but it gives an ideal).

Now, the problem is the following:

That DOS box can run well behaved DOS programs quite fine, but even installing a little EMS simulator (uses swap file) will fail.
At least, I hand no true success using these DEVICE loaders for DOS command line.

So all in all, installing a VBE TSR for DOS, as provided by the VGA chip manufacturers back in the day, may fail.
On the other hand, native VBE support in ROM of certain newer ISA VGAs will be available in that DOS compatibility box.
Just like the normal VGA BIOS.

That's why I wonder if these TSRs could be stuffed in an option ROM, similar to XTIDE Universal BIOS.
So they will be in memory before booting an operating system.
I'm asking, because those TSRs are simple COM files without the need for int21h API/ABI.
All they do is copying a memory resident copy of the VBE extension into RAM.

Which, I understand, may cause a bit of trouble on its own, of course.
The loader routine isn't needed anymore, if the payload (VBE routines) is placed in ROM directly.
Maybe the loader part can/must be stripped first?

Any thoughts on the matter? 🙂
Please reply below, any ideas welcome.

Best regards, Jo22