Re-doing vtvideo.c was on my list of stuff to look into, since a project which wanted to integrate some VT100 stuff from MAME/MESS had a license issue with that file (It is GPLV2+ unlike the rest of the vt100 stuff which is BSD; I may need to roll back to an older vtvideo.c from before the license was changed to GPLv2+ as a starting point, unless I can get the contributors to agree to relicense just that one file as 3BSD.)
The DEC rainbow-specific files were not an issue here (and can stay GPLV2+), just the shared vt100-and-rainbow shared video file, vtvideo.c
In fact, since the DEC video ASICs support both interlaced and non-interlaced video, it may or may not be worthwhile to re-write vtvideo.c from scratch anyway, once we have core interlace support working (which I believe is being worked on by Judge).
Anyway, dumping open collector proms isn't too hard: use 20kohm resistors from the prom output pins to vcc(+5v) while dumping. Your programmer may or may not already have internal pull-up resistors on the data bus, so it might not even be necessary.
Last edited by Lord Nightmare; 10/01/15 03:16 AM.