mg@notecnirp.Princeton.EDU (Michael Golan) (02/16/89)
I have recently got a 386 machine with the NEAT chip set and Parasize VGA plus 16 card. The card supposed to auto-detect the AT bus slot and allow REPSW instructions to access the screen ram with a 16-bit data width. The card comes with a program 16TEST which check if the card is running at 16 or 8 bits. Anyway, I installed it in an AT slot and it ran only at 8 bits. The jumper to force 16-bit width didn't help. I called Paradize and asked for help, and they suggested I put ANSI.SYS as my last driver in CONFIG.SYS. This did not help but REMOVING ANSI.SYS completely made the trick! The card ran at 16 bits width. I have verifed that speed has indeed increased with some other benchmarks. So I tried simtel20's ansi.sys replacements: zansi, nansi, qwikansi. All produced the same result: the card runs at 8 bits one ansi.sys is loaded. I almost gave up, but found yet another amazing thing: If I run BENCH24 from the PC-Magazine benchmark 4.1 (video speed check), the card SWITCHES to 16 bits after it was in 8 bits from the load of ansi.sys! Can anyone explain what is going on? Is it the Bios that mess things up (AMI)? I don't know enough about the AT architecture but obviously someone must tell the CPU that for some addresses it can only write in byte-width, in which case the CPU put only one byte at a time on the bus. Obviously ansy.sys mess up this info, and the pc-mag bench reset it! I tried to remove 'out' instructions in zansi.asm and run again, but it didn't help. Thanks in advance Michael Golan mg@princeton.edu