Supersoft/Landmark Diagnostic ROM - Use of VGA cards
On page 5 of the user manual is the following:
It is important to note the "self-initializing".
Landmark's definition of "self-initializing" is explained in the bottom block on page 8:
Requirement #1: So that means that only VGA cards that do not rely on certain routines in the BIOS, can be expected to work.
Requirement #2: But another requirement is that the VGA card be compatible with the computer. For example, some VGA cards do not work in the IBM 5150 (IBM PC) and some do not work in the IBM 5160 (IBM XT).
So you need a VGA card that meets both requirements.
I have VGA cards that meet requirement #2 (they work in the 5150/5160 with the IBM BIOS chip fitted), but because they do not work with the Supersoft/Landmark Diagnostic ROM, I have to deduce that they do not meet requirement #1.
I have yet to hear of anyone reporting that they have a VGA card that works with the Supersoft/Landmark Diagnostic ROM.