How to choose a new 386 UNIX PC...

Scott Wiesner scottw at ico.ISC.COM
Sat Sep 16 05:00:12 AEST 1989


Subject: Re: How to choose a new 386 UNIX PC...
Newsgroups: comp.unix.i386
References: <645 at visdc.UUCP>

>From article <645 at visdc.UUCP>, by jiii at visdc.UUCP (John E Van Deusen III):
> In article <16081 at vail.ICO.ISC.COM> scottw at ico.ISC.COM (Scott Wiesner)
> writes:
>>
>> On the subject of graphics coprocessor boards, the IBM 8514/A looks
>> very good, and when the AT clones of this board become available later
>> in the year, there will be a lot of happy people.
>>
> 
> In his Hardware Review in the Jan 1989 BYTE Magazine entitled "Pixels on
> the March", Bradley Dyck Kliewer reviewed the 8514/A coprocessor board.
> In its highest resolution mode (1024x780 pixels x 16 colors) the 8514
> sends an interlaced signal to the display.  It has been stated several
> time in this newsgroup that 1024x768 interlaced is almost
> indistinguishable from 800x600 pixel SVGA.  

The 8514/A has 256 colors in its highest resolution mode.  IBM's board
does indeed produce an interlace display, but I'd have to disagree with
the claim that this is indistinguisable from 800x600 SVGA.  I certainly
feel that non-interlaced is far preferable to interlaced, but I think
many people will agree that even an interlaced 1024x768 with 256 colors
is better than 800x600 with 16 colors.  This is mainly a personal 
preference call.


> This is, of course, just
> the sort of technical problem that the clone makers delight in
> rectifying, so I guess maybe I'll be happy when this board becomes a
> universal standard.  

As I mentioned, the boards are coming, and I believe many if not all will
support a non-interlaced display.  Several will also provide a resolution
of 1280x1024.

> What I really want to do is put together a 1024x
> 768x16 color noninterlaced X-terminal, based on a PC, that can update
> the entire screen in less than 2 seconds.  

Could you explain what you mean by "update the screen in less than 2
seconds"?  If all you've got on your screen is a color background and
no windows, you can certainly update in less than 2 seconds.  If you've
got something very complex displayed, not even a SPARC or MIPS based
machine with a very high performance display would be likely to update
it in 2 seconds.  When you say "based on a PC", do you mean an XT-class
PC, or a 386-class PC?

> I think that a SVGA adapter
> with real 16-bit latch registers should be capable of something in the
> range of 5 to 10 seconds.

This is an interesting comment.  I'm not aware of any VGA boards with
16 bit latches, or any plans to produce such a board.  There's certainly
no existing software that could deal with such a board.  This is kind of
like saying a PC based on a SPARC processor will be faster than one based
on a 386.  It is a true statement, but probably doesn't get you what
you wanted.

How do you arrive at your update time of 5 to 10 seconds for such a board?

Scott Wiesner
Interactive Systems



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