Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!ames!ucbcad!ucbvax!decvax!decwrl!sun!wdl1!kimery From: kimery@wdl1.UUCP Newsgroups: comp.os.minix Subject: Re: MINIX and the Tandy 1000 Message-ID: <5650002@wdl1.UUCP> Date: Thu, 9-Apr-87 22:42:58 EST Article-I.D.: wdl1.5650002 Posted: Thu Apr 9 22:42:58 1987 Date-Received: Sat, 11-Apr-87 19:44:01 EST References: <472@moncol.UUCP> Lines: 41 / wdl1:comp.os.minix / ast@cs.vu.nl (Andy Tanenbaum) / 3:22 am Apr 8, 1987 / In article <472@moncol.UUCP> john@moncol.UUCP (John Ruschmeyer) writes: >>Summary: MINIX won't run on the Tandy 1000. >> Memory management on the 1000 is a tad different than on a real PC- >> actually it's closer to that of a PCjr. In short, there is no dedicated >> video memory; rather the top 16K is stolen for this purpose and somehow >> mapped into the 0xB800 segment. Thus, ny 640K Tandy 1000 is really a >> 624K machine. >A number of people have sent me mail about problems with the Tandy. Maybe >the problem is as follows. MINIX expects a video RAM at address 0xB0000 if >the motherboard switches say there is a monochrome adapter installed and >at 0xB8000 if there is a color adapter. If it tries to write to those >addresses and nothing is there, the computer will just hang. Conceivably >something is going wrong with the mapping. I would suggest writing a little >test program under MS-DOS or some other system that just writes characters >to 0xB8000 or 0xB0000 to see if that works. Unless I have missed some strange and mysterious working of the tty driver it may not be as strange as it seems. I added a few printf's around line 4495 to display the type of keyboard that it thought it was seeing. Guess what. The messages showed up and then screech the machine locks up. From what I've seen so far it doesn't look as if thetty driver is the problem. My next guess is the floppy driver. (of course my next guess could be anything too......) I am slowly but surely tuning in on the problem. If enough people are interested (break out the hip waders) I'll be glad to share the changes I have made so far (both lines of them). Oops, another change just let me change the cursor size, move it to the lower left hande corner of the screen AND access the floppy before locking up... (maybe in a few days, I'll see the sizes printout before it locks up....) Sam Kimery kimery@ford-wdl1 sun!wdl1!kimery Merry Feast of the Pig!