> What exactly is MTC, and would I need it in order to sync an Atari
> STFM to a PC?
MTC is a time code that measures time in hours, minutes, seconds, and
frames, from a starting point (usually 0:00:00:00 but there can be an
offset) to wherever you are in the song, or other program. It is
similar to the broadcast standard SMPTE time code, but it goes through
a MIDI interface and has its own data format.
The Atari computers of that vintage have a MIDI IN and OUT port, so
that's a good start. You will also need a MIDI interface for your PC.
Also, you'll need software that works with MTC. Most PC sequencers and
DAW programs can "chase" to incoming MTC, but do you have a program for
your Atari that can send MTC? Unless people are writing new or updating
old programs for this chestnut, it's not likely. You may be able to use
SPP (Song Position Pointer) or, on the most basic level, MIDI Beat
Clock, to synchronize the two computer.
How much of a battle are you willing to fight to keep or put the Atari