> -----Original Message----- > From: Paul Flo Williams via cctalk <[email protected]> > Sent: 05 February 2024 16:24 > To: [email protected] > Cc: Paul Flo Williams <[email protected]> > Subject: [cctalk] Re: vt220 firmware source? > > On Sun, 04 Feb 2024 16:26:57 -0700 > Richard via cctalk <[email protected]> wrote: > > > In article <[email protected]> you > > write: > > >I'm about to dive in to commenting the disassembly listings, but > > >figured I'd ping here to see if anybody might have done this already > > >in case I wouldn't have to start from scratch? > > > > Give IDA Pro or Ghidra a crack at it to help you make sense of the raw > > disassembly. > > > > I made pretty good progress on VT100 ROMs before Paul Williams put up > > a completely reverse engineered commented listing. > > 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.
Hello 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? Thank you so much! Rob > > 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.
