Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!mit-eddie!uw-beaver!blake!ogccse!littlei!omepd!psu-cs!reed!tektronix!tekgen!stephenc
From: stephenc@tekgen.BV.TEK.COM (Stephen Coan )
Newsgroups: comp.sys.cbm
Subject: Re: Faster IEEE-488 devices (was Re: SEQ file access speedup)
Summary: I would NOT recommend the use of the MC68488 GPIA chip from Motorola.
Message-ID: <4125@tekgen.BV.TEK.COM>
Date: 21 Feb 89 17:34:49 GMT
References: <89Feb10.182100est.2732@godzilla.eecg.toronto.edu> <35528@tut.cis.ohio-state.edu>
Organization: Tektronix Inc., Beaverton, Or.
Lines: 38

In article <35528@tut.cis.ohio-state.edu>, erd@tut.cis.ohio-state.edu (Ethan R. Dicks) writes:
> In previous articles, many people put forth suggestions regarding speeding
> up IEEE transfers.  I have not been able to locate one, but Motorola
> produced (produces?) a chip called the MC68488, an eight-bit I/O bus chip,
.
.
.
> Ethan R. Dicks       | ######  This signifies that the poster is a member in
> Software Results Corp|   ##    good sitting of Inertia House: Bodies at rest.
> 940 Freeway Drive N. |   ##
> Columbus OH    43229 | ######  "You get it, you're closer.

The 68488 chip is buggy.  It also adheres to the 1975 version of the
standard, not the later versions (1978, 1980, 1987).  The major test
equipment manufacturers have given up on using this chip in new designs
(Fluke, HP, Tektronix, etc.).  I also would not recommend the NEC 7210 chip
due to many problems in it as well.   The bus does support bus speeds of up
to 1Mbyte per second, usually with a DMA controller involved.  The other
choices avaiable are the TI-TMS9914A and the INTEL-8291A chips.  The
interface chips to the IEEE-488 most used are the 75160, 75161 chips by TI
or National.  My background is that I have been extensively involved in GPIB
testing for Tektronix for 10 years and have worked with both TI and Intel in
getting them to revise their chips to their current "A" versions.  I have
also participated in the generation of the newest IEEE versions of the
venerable GPIB standard, the ANSI/IEEE Std 488.1 and 488.2 1987. 

If anyone wants details on problems, drop me a line and I'll send you
information.  That information does not need to be expounded here.

  Stephen L. Coan
  Tektronix, Inc
  Beaverton, OR  97077
  stephenc@aice.bv.tek.com
-- 

			Steve Coan
			tektronix!tekgen!stephenc
			(503) 627-1794