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From: hubble@cae780.UUCP
Newsgroups: comp.os.minix
Subject: Minix on an ATronics Clone
Message-ID: <3730@cae780.TEK.COM>
Date: Wed, 8-Apr-87 15:44:13 EST
Article-I.D.: cae780.3730
Posted: Wed Apr  8 15:44:13 1987
Date-Received: Sat, 11-Apr-87 08:36:02 EST
Reply-To: hubble@cae780.UUCP (Larry Hubble)
Organization: Tektronix/CAE Systems Division, Santa Clara, CA
Lines: 36
Keywords: Clone, Diskcopy, EGA Problems
Summary: It runs (a few glitches, however)

I just received my floppies this past weekend.  I have a
PC/AT Clone built by ATronics which can run either at 6Mhz
or 12Mhz with 1 Mbyte memory.  Minix came up fine and appeared
to have only a few problems.  I used the 640K PC version.

BTW, I copied my original Minix floppies with Diskcopy and
experienced no problems.  The copies were used for all further
Minix investigations.

My graphics device is the Megagraph Plus EGA clone.  It
should be no surprise that I experienced the same problems
others have already reported (After several screens of text,
only blanks are printed until the last viewable characters
disappear off the top of the screen, then the missing
characters magically appear).

After a little investigation, it is clear that the EGA clone
handles the Video Origin differently than Minix expects.
First of all, there appears to be more that 16K bytes of
RAM there and the video line being refreshed does not wrap
around at the end of RAM.  I am in the process of changing
the way Minix does it's scrolling (I'll post the changes if 
there is interest).

Since Minix takes over keyboard interrupts, I am unable to
get to 12Mhz mode (it takes a CNTL-SHIFT-\). If anyone knows
how, let me know.

And finally, I have a Seagate ST4906 80 Mbyte hard disk
which totally confuses Minix.  That will take a considerable
revamp of at_wini.c.  If anybody has already done it, I
would appreciate hearing about it.

Thanks in advance.
			    Larry R. Hubble
			    tektronix!hubble@cae780.UUCP