HP-41 and video interface 82163a / 92198a

[Garth Wilson]

There's a Mountain Computer MC00701A 80-column HP-IL video adapter, with manual and power supply, on the big auction site right now. (It's not mine. I'm not involved.) Search for:

HP 41C 71C Mountain Computer MC00701A HP-IL Video Interface

I'm pretty sure it's the same thing as the HP92198 because "MC00701" is the HP-IL device identifier I use to find the HP-IL address of my own HP92198 with my HP-41cx or 71B. The manual looks identical to mine also. Can someone confirm that it's the same model? Which number was used first? When and why was there a change? The price at the moment is only $10 (with one bid), but mine works fine and I definitely don't need a second one sitting around.

Mine has two EPROMs in it. As you may know, EPROMs were only guaranteed to hold their data for something like ten years (although I've never seen one go down, even after 20-30 years); but I refreshed mine and kept copies of the images (in Intel Hex format) in case anyone else needed them to re-program theirs. I need to get that up on my website, but I just haven't done it yet. One of the EPROMs has the character generator info, so you could change that one and make your own character set if you wanted to. It would not be hard at all, assuming your EPROM programmer has a binary edit mode. You could have more than one and change them out, or stack them in a jury-rigged socket (there's plenty of vertical room) and use a switch on the chip-enable lines to select which EPROM to use. Another way would be to use a denser EPROM and have the switch change the state of one or more of the higher address lines, to select which character set to use.

My 92198 sat in the closet unused for many years, but since one of my oscilloscopes on the work bench went down recently and I couldn't get it fixed, I got the 92198 back out and filled the spot on the workbench with it and have used it a few times recently again.

FWIW, my ebay identifier is wilsonmines. (I think we're supposed to include that in posts if we talk about ebay.) Again, I have no part in this sale. The notice about it came up in my emails and I hope it goes to a good home where it will be valued and used.