Date   : Wed, 20 Jul 2011 20:43:29 +0100
From   : profpep@... (Mike Pepper)
Subject: Emulating the 80186 CoPro on an ARM CoPro

> On 20/07/2011 19:27, Rob wrote:
>
> > IEEE488
>
> Ah, yes, I think that was it.
>
>
> > - a serial bus used mainly to communicate with laboratory
>
> Are you sure it isn't parallel? Seemed a lot of pins for a serial link.
>
It was 8 bit parallel, and used open collector outputs to allows for a total
of 16 devices, including the controller. There was a sophisticated
handshaking protocol to allow devices of very different sppeds to talk to
each other, and a interupt and polling system to allow devics to request
servce, (as well as a lot of other stuff). Invented by Hewlett Packard for
instrument control, and later used by them for peripherals on their earlier
workstations and PC's, (like the 98xx 68000 based series and the HP150
'touchscreen' units, an early 'sort of' compatible - which ran DOS up to
3.31, but no way would they run Sidekick or MS flight sim). On HP machines
it was called HP-IB.

I used it a lot for controlling test rigs, and HP BASIC had built in
support. I made a sort of cut down version to alllow me to make a pseudo
cluster machine out of BBC's, using a custom inteface box, and the user
ports. What can I say, I had this thing for fractals at the time, and a
moving population of repaired school machines, and used the system to test
repaired machines, if they could do an overnight run, they went back to the
school.

I had the cat problem too - I ended up making my own auto save/restore
because our cat would get into my room and walk on the keyboard, losing
several hours of fractal work. I used to take screen pictures with a
Polaroid SX70, it's remote trigger pin socket was wired to the relay dry
contacts on the cassette port. A quick *MOTOR on/off and I had a picture

Mike