From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Wed, 30 Aug 1995 21:36:59 -0400
From: geoffc@plan9.att.com geoffc@plan9.att.com
Subject: 9nextstation
Topicbox-Message-UUID: 1e2c3ba4-eac8-11e9-9e20-41e7f4b1d025
Message-ID: <19950831013659.Q8VtN_hKRcl9QSgEMM12SCjYjN38ngijGkSX-7_v3q4@z>

today i got plan 9 to run on a nextstation with old (2.1) boot
roms.  the other nextstations around here have 2.2 roms.
n.b.: rob tells me that plan 9 on nextstations needs at least 16mb.
these diffs are relative to the cd rom.

geoff collyer


diff ./io.h /sys/src/9/next/io.h
19a20
> #define VIDEOOUTLIMIT	IO(0x02004184)
diff ./main.c /sys/src/9/next/main.c
66a67,76
> 
> 	/*
> 	 * the boot rom is supposed to set all the video out registers sensibly,
> 	 * and indeed the v2.2 boot rom does so.  The v2.1 boot rom does not,
> 	 * and the video limit register contains a very large garbage number;
> 	 * thus we need to set the limit register here in order to get `clock'
> 	 * interrupts near each frame end to run the scheduler.  The value 0xea
> 	 * is what the v2.2 boot rom sets the limit register to.
> 	 */
> 	*(ulong*)VIDEOOUTLIMIT = 0xea;