IC1	LC3517AL-15K
2	HG62E08R10FS
3	6801V0B55P
4	74LS05
5	74LS02
6	74LS05
7	74LS32
8	74LS04
9	74LS74
10	74LS138
11	74LS573
12	74LS86
13	74LS688
14	74LS93
15	74LS688
16	5218A


The external connector box has a 74LS05 to drive the MIDI out and MIDI thru, and a Sharp PC900 optoisolator for the MIDI
in.  I've listed the pinout of the DB9 connector below.

DB9
1	Ground
2	TTL MIDI In
3	Metronome Out
4	Tape In
5	+5v
6	Ground
7	TTL MIDI Out
8	Tape Out
9	+5v