Path: utzoo!utgpu!attcan!uunet!seismo!sundc!pitstop!sun!amdcad!ames!nrl-cmf!cmcl2!rutgers!bellcore!tness7!killer!chasm
From: chasm@killer.DALLAS.TX.US (Charles Marslett)
Newsgroups: comp.os.minix
Subject: Re: MINIX expanded memory
Summary: Any STB Memory Companion cards out there?
Message-ID: <5667@killer.DALLAS.TX.US>
Date: 29 Sep 88 02:58:59 GMT
References: <508@uvicctr.UUCP> <3044@hubcap.UUCP>
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 28

In article <3044@hubcap.UUCP>, rwberry@hubcap.UUCP (Robert W Berry) writes:
> Never could keep Extended and Expanded memory straight.  My bad. 
> But the general point still applies.  Those of us in PC-land are left
> to the mercy of our EMS card makers.
> 
> I would apreciate it if you could send (or post if you think it's
> worthwhile) another copy of your EMS handler.  It might just get us
> started on the right track.

. . .

> Thanks in advance,
> Bob

The STB Memory Companion is a very simple EMS card (like the original Intel
card) -- it has one of 4 base addresses 0x258, 0x25C, 0x268 or 0x26C and the
4 paging registers are at 0x0***, 0x4***, 0x8*** and 0xC*** for each of the
4 possible board addresses.  The frame buffer is set using switches on the
board (usually at 0xD000:0x0000).  To enable a page at one of the 4 16K page
buffers in the frame buffer, just "OR" the start address with the board base
address and write the page number + 0x80 to that I/O address.  To disable
the 16K page entirely, just write any value less than 0x80 to I/O address.

(I sure hope I got this rite! (:-)

Charles Marslett
STB Systems, Inc.  <-- Apply all standard disclaimers
chasm@killer.dallas.tx.us