et4000/w32 ISA (Machspeed 1600)

et4000/w32 ISA (Machspeed 1600)

[Kenji]

I've gotten success to make my et4000/w32 graphic card use as 1024x768x1i
mode.   I hope this may help someone of Plan 9 fans.

The card is "Machspeed 1600", where I don't know its exact name, because
I picked it up from my friend's junk box without manual.  This is a ISA card.

Ami (1985-1991)BIOS reports it as "Machspeed 1600, Chipset: Tseng Labs
et4000/32".

I have lines in /lib/vgadb as follows:

ctlr
      0xC0076="Tseng Laboratories, Inc. 10/14/93 V8.00N"
      link=vga
      clock=ics2494a-304
      ramdac=att20c490-80
      ctlr=et4000-w32
      hwgc=et4000hwgc.

In addition, you may write two lines in plan9.ini file as,
      monitor=multisync65
      vgasize=1024x768x1i.

It may noteworthy to describe that I had to set BIOS as VGA Shadow enable 
to avoid panic during change to SVGA mode.  Here, I tried to set 
      vgactlr='0xC0076=Tseng Laboratories, Inc. 10/14/93 V8.00N',
but it failed to avoid panic, although it may concern only with my older
BIOS.

I don't know why/how enabled BIOS shadow co-works with Plan 9, though.

Kenji