graphics under SCO xenix with a hercules adapter

[Jim Morton]

In article <2093 at runx.ips.oz>, emmett at runx.ips.oz (Emmett Lazich) writes:
> 
> /dev/mono seems to return the correct far address for the display memory 
> (I bet it hasn't set up the correct limit in the segment descriptor!).  
> But I cannot put the CRT controller into graphics mode!
> No ioctl() call (or stty command) will put the herc board into graphics mode.
> SCO didn't seem to want to support it?

These definitions were added in (I think) 2.2.2. They may be 386 only:

comcrt.h:#define M_HGC_P0	0xe0	/* hercules graphics - page 0 @ B0000 */
comcrt.h:#define M_HGC_P1	0xe1	/* hercules graphics - page 1 @ B8000 */
machdep.h:#define SW_HGC_P0  (MODESWITCH | M_HGC_P0)
machdep.h:#define SW_HGC_P1  (MODESWITCH | M_HGC_P1)

If they aren't in your 286 release, you can use the /dev/mono address and 
either write a tiny fooopen() fooclose() driver that does ins & outs on the
Hercules controller ports to enter and exit graphics mode respectively, or 
use the /dev/mem - /dev/port device that Steve Dyer posted here a while ago.
(I think it was major #4, minor #4, and you can adb or lseek() to the port
address - reads will do an in(), writes will do an out() ).

--
Jim Morton, APPLiX Inc., Westboro, MA
UUCP: ...harvard!m2c!applix!jim
      jim at applix.m2c.org