Ron Gilbert (of Maniac Mansion / DOTT / Monkey Island / SCUMM fame) speaks to this in an interview he gave at Handmade Con, you can find it on youtube.
IIRC he says they used UNIX workstations to develop Maniac Mansion/SCUMM for the C64. Complete with hot loading of levels, presumably they had a similar hardware interface to what's shown in TFA for manipulating C64 memory contents from the UNIX box.
IIRC he says they used UNIX workstations to develop Maniac Mansion/SCUMM for the C64. Complete with hot loading of levels, presumably they had a similar hardware interface to what's shown in TFA for manipulating C64 memory contents from the UNIX box.