MPU-401 / MPU-IPC-T needs the rom dumped from the 6801V0B55P MCU (which handles 'intelligent mode', which a bunch of games used) on the board first. I have an LAPC-I here, and am sending it out for the MCU to be removed and read off soonish (afaik there is no read protection but reading it is awkward). It will hopefully be done within a week or three.

AFAIK differences between MPU stuff is:

MPU-101 and MPU-104 are a control-voltage-to midi interface and a 4-input midi switch box respectively and are totally unrelated to this stuff. MPU-101 is rather cool though, since you can use it to do analog synth stuff driven via MIDI.

MPU-401 is an external white metal box which can connect to appleII/ibm pc/other stuff with a custom system->db-25 interface card specific to the system it is attached to. I don't know if it has any processor inside other than the MCU. See http://vogons.zetafleet.com/files/mpu401-1024t.jpg and https://upload.wikimedia.org/wikipedia/commons/0/06/Roland_MPU-401.jpg (MCU is visible in there at I think IC5)

MPU-IPC-T is an MPU-401 completely integrated onto an ISA card, with much of the extra logic of the mpu-401 integrated onto a single ASIC. It uses an incompatible DB-25 interface to the MPU-401 (since the 'metal box part' is much smaller and no longer has the MCU inside) but to software it looks the same way, AFAIK. See https://upload.wikimedia.org/wikipedia/commons/0/0b/Roland_mpu-ipc-t.jpg (MCU at IC5).

LAPC-I is afaik literally an MPU-IPC-T and a CM-32L synthesizer crammed both onto an ISA card; it has all the same components as an MPU-IPC-T plus all the LA32-and-reverb releated stuff and the 8098 cpu of the CM-32L. It is a very large unwieldy ISA card. It uses a DB15 connector for external MIDI, unknown whether compatible with the midi/joystick standard from the sound blaster; the metal box it attaches to is called the MCB-1. See https://upload.wikimedia.org/wikipedia/commons/1/11/Lapc-1.jpg (MCU is located at IC22)

LAPC-N is an NEC PC9800 card which implements an LAPC-I (it uses a later 80198 processor and a different code rom though, and probably has an NEC 'rom bios' on it on a funny custom labeled '2G1'). The ROMs for this are not dumped, except for those in common with the LAPC-I. It uses a DB15 midi interface port; the metal box it attaches to is called the MCB-2 and is NOT compatible with the MCB-1 used on the LAPC-I.

LN

Last edited by Lord Nightmare; 01/13/13 04:43 AM. Reason: clarified
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