Version 1.02 - Alesis ADAT BRC Service Manual

Version 1.02

Date of Release: 04/28/93
Checksum (Processor: int=64EB; ext=643C - REV2)
(EPROM: int=78FD; ext=7874)
NOTE: This software coincides with a hardware change to the SMPTE input circuitry. Refer to
Appendix B for details.
A. Processor Fixes:
1. Generation of MTC 29.97 non-drop and drop corrected.
2. Generation of SMPTE before the song start corrected.
B. EPROM Fixes:
1. MTC full message rate was indicating 30 non-drop for 29.97/30 drop and 30 drop for
29.97/30 non-drop. Now indicates 30 non-drop for 29.97/30 non-drop and 30 drop for
29.97/30 drop. (There is no specification for 29.97 in the MTC full message).
2. Fix sub-beat editing of locate point.
3. ExtSync freeze: Unit would eventually freeze if clock source=48K and ext. sync enabled.
This has been fixed.
4. External sync improved (coincides with hardware mod). There is now more tolerance to
incoming SMPTE (jitter, wow and flutter, etc.).
5. Fixed occasional MIDI Clock drop-out at tempo change.
6. If tape offset type was counter offset type, and then changed to locate offset type without
editing the locate numbers, then when tape offset was enabled, units may have had incorrect
offsets. This has been fixed.
7. If SMPTE rate was drop frame (29.97 or 30) and SMPTE Start Offset had non-zero min, sec,
frames, then ADATs would drop out of sync (e.g. when passing through non-drop minute).
This has been fixed.
C. EPROM Changes/additions:
1. Deferred record can now be initiated in indirect lock mode. It can also be initiated from the
pre-audio (before absolute time 00:00:00:00) section if auto-punch is enabled with a punch-
in point that is within the audio section of tape.
2. Shorten the pause that occurs before going into play after locating.
3. Make sure any pending record is terminated when a locate is initiated by the user.
4. If tape offset enabled while playing, re-issue play command
5. On power-up, the song that was selected when the unit was powered-down is remembered.
(used to always power-on with Song01 selected)
6. When saving data to tape, disable Digital I/O. When digital input is enabled, no data
(data=0) is written to tape.
7. Allow punch-in/out in continuous mode.
C-3