The 108 memory locations for storing setups is a real feature of the APR-5000 series tape machines. The APR-24 manual alluded to this but did not provide any instructions.
I have the only APR-16 that Sony ever made, but it is essentially the same as an APR-24. My APR-16 is running firmware version 5.01.06.0.
It appears that there are a total of 18 total preset locations in the APR-16 (and presumably the APR-24).
There is a small DIP switch board like the ones on the APR-5000 head assemblies located underneath the control panel at the left side, near the Network switch. Removing the two screws in the top front of the side of the machine releases the control panel to swing forward on its hinges.
Switch positions 7 and 8 appear to be the only active positions on this switch.
Switch 7 8
0 0 Invalid
0 1 8-tracks
1 0 16-tracks
1 1 24-tracks
While this is more limited than the APR-5000, the good news is that each of the three valid settings provides a different memory storage location. This means there are a total of 18 storage locations on the APR-16, 6 each for the 8-, 16-, and 24-track settings. The Preset 1, Preset 2, and Preset 3 positions could conceivable be used for different head assemblies, with both speeds active.
My current thinking for this is:
8-track — Preset 1 — 8-track 1″
8-track — Preset 2 — 8-track 1/2″
8-track — Preset 3 — 8-track 1/4″ (using an APR-5000 to pull tape)
16-track — preset 1 — 16-track 1″
16-track — preset 2 — 16-track 1/2″
16-track — preset 3 — 4-track 1/2″ (two possible presets: tracks 1-8 and 9-16)
24-track — preset 1 — 7-track 1/2″ IRIG (two possible presets: tracks 1-8 and 9-16)
24-track — preset 2 — possible future 14-track 1″ IRIG
24-track — preset 3 — future, unassigned
I tried the other switch combinations and they did not seem to do anything. It’s too bad that this is only a 15/30 in/s machine as there is a need to go to 7.5 in/s for audio tape (at least at 4-track 1/2″ and even more speeds for the IRIG instrumentation tapes). However, we can transfer 7.5 in/s and 3.75 in/s 4-track 1/2″ on our Sony APR-5000 pair.