On Sun, 04 Feb 2024 16:26:57 -0700 Richard via cctalk <cctalk(a)classiccmp.org> wrote: Well, in case it helps, I'll explicitly disclaim any intention of disassembling the VT220 :-) After the VT100, I did make a start on the VT102/131 combination but it seemed too samey to hold my interest. More than 20 years ago, I started on the VT320, as my personal favourite, but I didn't understand how to tackle emulation at the time, the 8051 emulator I wrote had flaws, and I spent a long time on getting the emulated video timing correct enough to even pass self test! If only the VT320 had had a technical reference as comprehensive as that published for the VT100. I will return to it at some point, probably using some else's 8051 core, as Peter Sichel (last head of DEC's terminals group) bet me that I wouldn't be able to do it. At the moment, I'm tackling another full commentary, but it may well have an even smaller audience than that for the VT100; I'm 83% through gutting the arcade game Star Force. I've even fixed two æsthetic bugs in the game, 40 years too late for anyone to care. At least this is Z80 assembler, and tinkering with that has always made me *very* happy. Paul.

Your annotated VT100 listing was invaluable in helping me to fix my own VT100 (still not working though, but on the video output side). Would be interested in how you did it, I get the impression from your message that you used an emulator to observe the behaviour?