Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!bpa!cbmvax!vu-vlsi!devon!shockeye!hermit
From: hermit@shockeye.UUCP (Mark Buda)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Paradise VGA Plus undocumented video modes
Keywords: how do I do it?
Message-ID: <253@shockeye.UUCP>
Date: 16 Dec 88 21:44:54 GMT
References: <247@shockeye.UUCP> <1180@skinner.nprdc.arpa>
Reply-To: hermit@shockeye.UUCP (Mark Buda)
Organization: The Lab Rats
Lines: 29

In article <1180@skinner.nprdc.arpa> malloy@nprdc.arpa (Sean Malloy) writes:
>In article <247@shockeye.UUCP> I ask:
>> [How do I write to the bottom of half of a Paradise VGA board in
>> undocumented video modes?]
>
>I don't want to rain on your parade, but 640x480x256 on a VGA board
>requires 44K _more_ memory than a 256K VGA board has, so you won't be
>able to use that mode unless you've got 512K on your VGA board (it
>actually requires 300K).

Oh. I hadn't bothered to think of that. Nevertheless, I get the same
problem with 640x400x256 mode, which requires less than 256k.

>The reason that you're crashing your system
>is that you're trying to write into nonexistent memory on your
>graphics board.

No that's not it, because the same problem happens in 640x400x256 mode.
Anyway, why would disabling interrupts keep it from crashing in that case?
The board has 256K.
I know how to put it into 640x400x256 mode.
I _can_ write to the bottom half of the screen.
I want to know if there is a 'right' way to do it, that doesn't involve
having to disable interrupts.
-- 
Mark Buda / Smart UUCP: hermit@shockeye.uucp / Phone(work):(717)299-5189
Dumb UUCP: ...rutgers!bpa!vu-vlsi!devon!shockeye!hermit
I hate this $%$@%!$@%!@$%@#$@!% machine.
"A little suction does wonders." - Gary Collins