I was trying to find something that would print on the BBC Master and found a BeeBug dumpmaster rom.
./mame64 bbcm -printer ap2000 -romimage1 dmpmastr
It kinda works, but it seems to get its workspace corrupted when I do a *LDPIC. You're supposed to be able to hit CTRL+SHIFT+@ (mapped to backslash) to make it dump.
*BPRINT P0 V A D will setup the hotkey but it doesn't dump properly.
*BPRINT I V will do a vertical dump in inverse.
*HELP BPRINT shows you the settings.
Still, it's kinda neat to see it work.
edit: after fiddling around, I discovered that the rom scrnprnt100 has a good hotkey setup: hit CTRL+P and it prints the screen, CTRL+SHIFT+P and it prints in inverse.
./mame64 bbcm -printer ap2000 -romimage1 scrnprnt100