lisa@phs.UUCP (Jeffrey William Gillette) (08/11/85)
[] I have been asked this by a colleague at the Duke Medical Center, and since I do not have the relevant hardware, I submit it for your suggestions. My friend has an AT, Xenix, an Enhanced Graphics Adapter, and the enhanced color graphics monitor. He has discovered that Xenix will boot happily with the EGA set for a normal (poor resolution) color character set, but will not boot with the EGA set for the high resolution font (which is, after all, the whole purpose of the expensive monitor). Evidently initializing the EGA for enhanced color is more complex than for my monochrome monitor - it is reported to involve rewriting a table pointed to by one of the "reserved" interrupts. My friend immediately tried to write a short assembly language program (patterned after his successful MS-DOS program) that does the required work. Obviously he ran into problems with the protected memory scheme. There is no obvious way to write to an absolute memory address on the 80286 in protected mode. Thus the question. 1) is there an easier way to initialize the enhanced color text mode for the EGA - one that will work within the constraints of Xenix and the 286? or 2) is there a simple way to get at an absolute address in Xenix and modify it? Jeffrey William Gillette uucp: ...!duke!phys!lisa The Divinity School Duke University