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HP92198 HP-IL 80-column video interface

PostPosted: Tue Oct 03, 2017 2:08 am
by Garth
Many 41 users are unaware of the HP92198 80-column video interface that Mountain Computer made for HP. I thought I should post a picture here that I took a few months ago during an HP-41cx project.


There's not much alpha shown there, but it does show the capability. I also didn't need 80 columns for what I was doing at the time, but you can see the clarity anyway. And yes, the 41 can do any number of columns you could want, using ACA (accumulate alpha) and related functions. Here's the front of the video interface box itself:


I refreshed the two EPROMs recently. One has the program material, and one has the dot information for forming the characters. It occurred to me that you could have various EPROMs for various character sets, and swap them out, or have them piggy-backed with only the OE\ pin individual to each, and use a thin wire to connect that to a DIP switch to select the one you want. I also kept Intel Hex files of the EPROMs so I could restore them if they did go south, or email them to someone who needs to re-program theirs.