[comp.os.minix] Display bugs

bc@njitsc1.njit.edu (Bill Cheswick) (07/28/87)

In article <1139@cognos.UUCP> brianc@cognos.uucp (Brian Campbell) writes:

[... some stuff deleted ...]

>     Oh ya, there was some talk about scrolling problems with Hercules
>cards somewhere in the distant past.  The only fix I saw for this
>problem was to change M_VID_MASK from 0FFF to 1FFF.  I tried this, and
>it didn't do the trick (although it did help a little).  I'm using an
>Everex Edge (HGA + CGA) that has 64k of RAM.  I tried using masks of
>16k, 32k and 64k as well, but none made the problem go away.
>-- 
>Brian Campbell          uucp: decvax!utzoo!dciem!nrcaer!cognos!brianc
>Cognos Incorporated     mail: 3755 Riverside Drive, Ottawa, Ontario, K1G 3N3
>(613) 738-1440          fido: sysop@163/8

I have had similar problems with the Sigma Designs Color 400 card.  Changing
the mask improves things.  I think the display card's 6845 emulation
doesn't wrap at the end of the buffer.  Has anyone else run into this
problem?  

I would be happier if Minix just did its scrolling in software and didn't
fiddle with the base display address.  Has anyone made that change to the
1.2 tty.c?



Bill Cheswick				ARPA:  cheswick@jvnca.csc.org
The Cygnherd of Morristown		UUCP:  bellcore!argus!njitsc1!bc