Questions regarding HP Roman character set

[Garth Wilson]

Last night I got my yellow monochrome monitor out and my HP92198 80-column, 24-line HPIL video interface which I had not used in many years. There was a note on the bottom of the HP92198 saying I had refreshed the EPROMs in 2004. I thought I should do it again now, but I couldn't tell the brand so that the EPROM programmer would be sure to use the right algorithm. I probably used the generic non-CMOS one before, 50ms and 25V. I did read the EPROMs into files though, so I can program new EPROMs later if necessary. (I do lots of backups, so there shouldn't be any way I'll lose it.) For now, the video is working. I just listed a program and key assignments and flags from my HP-41.

While I was in the programmer software, I decided to look at the data. It was pretty clear that U2 has the program material and U12 has the characters, ie, the info telling what dots to use in each field to form each character. It didn't take long to realize I could change the characters if desired. It always bugged me that I could have the ROMAN8 character set loaded in my HP71 to use with the Thinkjet printer but the monitor did not do the special characters but instead did inverse video of the normal characters for the ones with the high bit set. It might take a few hours, but the ROMAN8 set could be put in the HP92198. If you had to go back sometimes to the inverse video (like for spreadsheets where you're moving from one active field to another), you could have more than one ROM, and put a switch on it to select which one you want at the time. The switch would only have to affect the output-enable or chip-select pin, not all the data pins, let alone address pins.

I realize the HP92198 80-column interface is rare; but I expect things work similarly with the other, more common HP video interface which only did 40 columns.

Only partially related, but maybe someone knows: I was looking through my manuals for a way to print (in this case to the HP92198) HP-41cx text files, but found nothing. I could write a program to pull lines into ALPHA, up to 24 characters at a time, and use ACA (accumulate alpha) to piece longer lines together on the monitor or printer, but it seems like I shouldn't have to. [Edit: While looking for something else, I found such a program that I wrote 30 years ago; but again, it seems like there must be an already-provided way to do it.] Am I forgetting a built-in function? I have a 41cx, HPIL, and Extended I/O module (plus ZENROM and Advantage modules).