mitchell@MDI.COM (Bill Mitchell) (02/18/91)
In article <44850@nigel.ee.udel.edu> wjb@cogsci.cog.jhu.edu writes: ..... [stuff deleted] .... >I've tried to find out from vendors whether >this is implemented via the BIOS code or whether it is done in hardware. >Unfortunately, in at least one instance when I called the manufacturer their >technical support people couldn't answer the question. Given that DOS rules >the PC world and implementing it via code in the BIOS is easier then doing it >in hardware. Well, ... Since Minix bypasses the BIOS, translation >implemented that way wouldn't help. ..... [stuff deleted] .... Yes, it's very frustrating. I've several times thought about minix and asked if technical documentation for particular hardware items I was considering provided sufficient low-level information that I might have a chance of writing a driver for it. In nearly all cases, the answer has been "Huh?", "I dunno.", "No.", or "We don't release that info.". Seems many hardware manufacturers consider device acces thru BIOS calls a given. If it's a PC, this is the way it's expected to be done. Also seems that programmers implementing these BIOS calls often assume that PC/MSDOS conventions regarding BIOS work areas, etc. will be followed. As a practical matter, this means that these devices may be commonly used under PC/MSDOS but they're unusable under minix unless you're willing to forego support and spend a lot of effort on reverse engineering. sigh........ -- mitchell@mdi.com (Bill Mitchell)