HPIB [was Re: Kennedy to PC interface...]

Chuck Guzis cclist at sydex.com
Tue Feb 20 23:47:56 CST 2007


On 21 Feb 2007 at 2:25, Tony Duell wrote:

> There aren't that many HPIB buffer chips in common use. There's the TI 
> set (75160/75161/75162), the HP custom one, the various Motorola ones (I 
> forget the numbers), the Intel one (8293), and that's about it. Oh, 
> there's the kludge way, using open-collector TTL as drivers (or before 
> that, discrete transistors), and 7414's as receivers.

If you're communicating to a single device, it's possible to use a PC 
paralell port (particularly a bidirectional one) to do the job.  A 
very long time ago, I needed to draw a color pie chart.  I had a copy 
of Supercalc and a friend loaned me an HP 5-pen (IIRC) plotter that 
he'd picked up at the going-out-of-business sale of the Control Data 
retail stores.  I had a PC XT at the time.  The problem was that the 
plotter was GPIB only.

 I hacked the parallel port on the IBM MDA to do bidirectional I/O 
(easy--just a cut and a jumper).  I wrote a TSR that hooked the 
parallel port BIOS interrupt and translated the codes intended for a 
parallel-interface plotter to GPIB strings.  I told Supercalc that it 
was driving the parallel-port version of the plotter and bingo--I had 
my charts.

You can probably still find the code in one of the SIMTEL archives, 
but I can't remember what I called it--something like LPTHPIB, IIRC.

Cheers,
Chuck




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