When people refer to syncing two machines . . . do they mean that if I sync a drum machine to a tape deck (388 or 488 or whatever) that they will start and stop at the same time? I'm sure this is a redundant question but I can't seem to find anything on it. Sorry. I appeciate your help.
Basically, yes. It's often used when you have keyboard parts played by computer, like I do (or indeed a suitably intelligent drum machine).
In this setup, you can record a timecode on track 8 (or whatever, usually the last track), and feed it into a sequencer on a computer through a sync unit. This unit converts the timecode into a MIDI signal which tells the sequencer where in the song it is.
So, if you rewind to the start of the song and press PLAY, the computer will start playing from the beginning of the song. If you were to stop, wind a minute forward and press play, the computer would jump to one minute into the song etc. This also ensures that the computer keeps time with the tape, since the playback is never precisely the same speed each time. Without it, the two would slowly drift apart. A good synchronizer takes about 2-5 seconds to lock to a timecode.
You can also use this to lock two tape machines together and get more tracks. I also do this myself on more complex songs - with 1 track striped on each machine, I can have up to 14 tracks in total. In that setup, you need a sync box capable of taking two inputs and directly controlling the tape decks - these are rarer and more expensive than a typical MTC unit used for controlling a sequencer or drum machine. Note also that only some machines can actually be driven as a slave like this, though I believe the 388 is among these.
You would record a timecode on track 8 of both machines. One would be the master, and the other the slave. When you start the master, the slave will speed up, slow down or otherwise hunt until it reaches the same point in the song as the master is at and then match pace with it.
Since this seems to be a bit of a lost art, I had a camera rolling while I mixed one of my songs last year:
http://uk.youtube.com/watch?v=GYT0IuLt30I
The left-hand machine is master, the right-hand machine is slave and the far-right machine is the mixdown deck. Watch carefully when it begins and you can see the slave hunting. Also, around 1:33 I botch the mix and stop the master. If you listen, the slave grinds to a halt shortly afterwards.
If memory serves, the record for doing this was one of Scritti Pollitti's albums in 1984, which had no less than 5 Studer machines locked together giving them something insane like 115 tracks.