Xref: utzoo unix-pc.general:4477 comp.sys.att:8443
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!sharkey!cfctech!ttardis!rlw
From: rlw@ttardis.UUCP (Ron Wilson)
Newsgroups: unix-pc.general,comp.sys.att
Subject: Re: Should I buy a 3b1?
Keywords: PC graphics on AT&T 7300
Message-ID: <2421@ttardis.UUCP>
Date: 11 Jan 90 04:35:08 GMT
Organization: Gallifrey
Lines: 39

In article <10678@rama.UUCP>, lvw@rama.UUCP (Lyndon VanWagner) writes:
>I'm considering purchasing a used unix-pc (3b1, 7300) as a home machine.
>However, I would like to check on its MSDOS (if any) compatibility, when
>the DOS board is installed.  Can anyone give me their experiences with
>this?  Is the screen compatible with some IBM PC graphics board?
>
>-----------------------------------------------------------------------------
>Lyndon C. VanWagner		UUCP:	lvw@sc.harris.com
>Software Engineer		-or-	...!rochester!tropix!rama!lvw
>Technical Support Group		PHONE:	(716) 924-9303 ext. 226
>Harris Corporation, Scientific Calculations Division, Fishers, NY
>-----------------------------------------------------------------------------

I am reading from the AT&T "UNIX-PC Reference Manual."  In the section
describing the "DOS-73 Coprocessor" card, page 1.2, "General Description,"
the manual claims that the DOS coprocessor emulates a Hercules MONOCHROME
graphics card.  Further reading says that the card's hardware whatches for
something to write to the emulated screen memory and sets a flag to notify
the system to update UNIX-PC's display.

Additional IBM PC features emulated or provided:

	COM1:	(emulated)
	COM2:	(provided; fully implemented - presumably fully compatable)
		   (Intel 8250 Asynch Com chip)
	LPT:	(emulated)
	floppy  (emulated)
	   disk
	8253	(provided)
	   timer/counter chip
	8259	(provided)
	   interrupt controler
	socket for 8087 math coprocessor (provided)

However, I don't have a DOS coprocessor card, so I can't tell you how
well it really works.

I've thought about getting one, but the most recent price I've seem was
about $700 - still too high for me to consider it (yet).