[time-nuts] RS 232 to GPIB update on IOtech 488 series

[paul swed]

A thread has been running about using the IOtech rs232 to GPIB converters.
Thought I would share what I have run into all good.

These boxes come in two flavors
simple 1 device controller/peripheral
Full controllers that operate a full 488 bus and can also do the simple
modes.
IOtech made these for many companies as an example BlackBox, Omega and
National Instruments and a wide range of names and numbers. The rs 232 runs
all the way up to 57Kb/s on some boxes.

They all seem to hold up to the years quite well. Essentially the 5 I have
found at flea markets all work.
There has been a comment that you could simply change eproms and new
functionality would happen.
Thats most likely true in a series but not to make a simple into a full
controller. (Most desirable)
A full controller would be the IOtech 488a or 488ex most other numbers are
simple units with a bit more buffer or higher 232 speed.

But the difference between the simple and controller seem to really be 2
things.
The eprom and the addition to the ram socket of a DS1216 clock and memory
battery chip.
Believe it or not the DS1216s available from Mouser and perhaps DigiKey for
$28 each. Thats 1988 technology with a life.
The eproms for a simple and the 488ex full controller will be uploaded to
Diddiers site in the next few weeks.
Need a safe haven for those images.

Further I had NV corruption failing the 488ex. It actually all seemed to
work just fine actually. Just a red error light.
This was fixed by;
Pulling the sram chip and grounding all pins for 30 min.
Re-install
Command a warm reset and then a save. The light went away.
Further the original date time chip rolls over to 1900 not 2000. Don't
think that really matters a heck of a lot.
Or at least not $28 worth to me.

So a pretty hardy set of boxes and you can still find quite a bit of
documentation on most all of them.
Regards
Paul
WB8-TSL