[unix-pc.general] Should I buy a 3b1?

lvw@rama.UUCP (Lyndon VanWagner) (01/09/90)

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?

Or, should I wait for the Intel 386 prices to drop, and put ESIX on
it?  Of course, then I would have to wait for a year or so...  I am so
sick and tired of using my non-standard, floppy-based, MSDOS machine
(a Tandy 2000) and want a real Unix machine for home use!

How big is the following for the 3b1?  Where can I get support for it?
Where can I get software (like enhancements and a software development
system) for it?  (You see, I'm new to this newsgroup - so please be 
nice: no flames please).  I happened to read about a proposed System V
Rel 3.2 port for the 3b1.  What/if-anything has happened to this idea?
Was it canned because there wasn't enough technical documentation on the
in-nards?  (Its too bad, that when a company decides to drop and orphan
a machine, it doesn't make the technical information public domain).
-- 
-----------------------------------------------------------------------------
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
-----------------------------------------------------------------------------
Cornfield's Law (paraphrased):
	Before anything can change, everyone must agree.
	By the time that happens its a different problem.
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rlw@ttardis.UUCP (Ron Wilson) (01/11/90)

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).

res@cbnewsc.ATT.COM (Rich Strebendt) (01/12/90)

In article <2421@ttardis.UUCP>, rlw@ttardis.UUCP (Ron Wilson) writes:
| 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?
| 
| 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.  
| ... However, I don't have a DOS coprocessor card, so I can't tell you how
| well it really works.

I have a DOS-73 board, so I can comment from experience.  For
character graphics the emulation is quite acceptable.  I run programs
like Harvard Total Project Manager (Version 1.0) on it and the PERT
charts and Gantt charts look just fine.  For bit level graphics the
DOS board is absurd.  For example, if I try to run TETRIS on it, the
display looks like a TV set with a horrible horizontal sync problem.
Each line of the display is offset from its predecessor by a large
amount.  Any program that tries to do Hercules bit-level graphics
simply trashes the display.  This appears to be because the PC and the
UNIX PC screens have different numbers of pixels per row(?).

Add to this problem the problem that the memory is terribly undersized
for modern applications.  For example, HTPM versions beyond 1.0 are
too big to fit into the undersized DOS board's memory.  While it is
claimed that there is 512K of memory, only about 400K of it is
available for applications to use.

So, if you are looking to do fancy graphic applications using the
DOS-73 board, you may be disappointed.  However, if character level
graphics are sufficient for your needs, the board will probably do
fine as long as your application will fit.  Despite these limitations,
I personally have found the DOS-73 board to do a good job for the
kinds of things I want to do with it.

					Rich Strebendt
					...!att!ihlpb!res

zman@cbnewse.ATT.COM (william.j.zimmerman..jr) (01/13/90)

I have been using the DOS-73 card in a UNIX PC for a couple
of years now, and in general I am pleased. In real life I used
to have to test MS-DOS software on our network products
for compatibility. After testing, I almost always would try the
software on my DOS-73 card.

As Rich Strebendt pointed out in an earlier article,  some
s/w will just plain not run/hang the card. That's the worst
case. The best case is when you don't know that you are
running the card. A lot of s/w falls in between. One
outstanding example comes to mind. I just bought the 1990
version of Turbo-Tax and decided to see what it looked like
on the DOS card. Answer - incredible. When you tell it to
show you your 1040 min graphics mode, it makes a DOS CGA
display look amateurish.

If anyone wants to know what will run and what won't, write
to me - I may have tested it.

Bill Zimmerman att!iwlcs!wjz 708-979-7677