HP-85 Refurb Questions

[Steven Kutoroff]

I acquired an HP-85 which works, but needs some refurbishment.

I just ordered some belts for the printer, one problem solved (soon).

Next issue is with the keyboard. A number of the keys are very sticky, seems to be plastic to plastic friction (with grime). What is the best means of restoring the keys to full function? I am planning on removing the keyboard, the key caps, and then using a electrical spray cleaner. If any keys remain sticky, I was going to use silicon spray on them. Is this OK?

Finally, looking for new toys for it. Will the 82909A RAM 128K Memory card module work in an HP-85 made in April 1982 with an IO ROM (no mass memory ROM)?

My email is as above, but drop the * z *.
Thanks!

[Vassilis Prevelakis]

Hi Steven,

Sorry the 82909A may be used only on 85B and 86/87 models
only.

In general if you have an 85 with 16K RAM (without any
modules attached), then you have an 85A and you can only
add the 82903A 16K Memory module.

If the machine has 32K then its an 85B (or an 85A that has
been upgraded to B). In this case you CANNOT use the 82903A module, but you can use the 82908A and 82909A modules.

In any case the 82908A and 82909A modules only allow you to use a larger RAM disk (i.e. they cannot increase the base memory which is maxed at 32K).

In your case I'd be looking for an 82938A HP-IL Interface (but these are relatively rare) or an 82937A HP-IB Interface and a 82169A HP-IL/HP-IB Interface. These two combinations will allow you to connect to your HP-75 and 3421A over HP-IL.

**vp

[Steven Kutoroff]

There is one for sale on eBay, I was curious about it.

The information I found was not as clear on installation dependencies.

Thanks.
Steve