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Description
The Bit² BM-012 is an external MIDI interface for MSX2 and higher which came with MIDI-Saurus. The interface has three connectors on top of it: MIDI-IN, MIDI-OUT and MIDI-THRU (2nd MIDI-OUT). It has its own Z80A microprocessor, timer and memory capable to playback MIDI on the slower MSX2/2+ as well. This way the MIDI interface takes care of all incoming MIDI-commands and the computer can do other things at the same time.
Programming information was published in the MSX-Magazine Issue 1990/07, page-77 and Issue 1990/08, page-59, but this documentation is still only available in Japanese. It's confirmed that the interface works at port 70H-73H. Ports 71H and 73H are command ports and ports 70H and 72H are data ports. It was only sold in Japan and a few were imported to Europe. It's rare nowadays.
For games it's known Famicle Parodic 2 has support for this interface, but there could be some more.
Here's a video which shows how the MIDI-Saurus can perform. In the video it uses μ-Note.
Downloads
- Dump MIDI controller ROM v1.00
- MIDRY option /I0 or /I01 for MIDI-OUT 1 or option /I02 for MIDI-OUT 2 (MSX2/2+/MSX turbo R: Z80 mode) - also support for ReComPoser MIDI files (.RCP) The only MIDI player as known for MIDI Saurus
<Unconfirmed data found by looking at ROM dump>
ROM is mapped in external Z80 address space to #0000-#1FFF and 8KB SRAM is mapped to #E000-#FFFF. External Z80 is uses I/O ports #10-13 and #18-#1F to communicate to outside world. ie. I/O port #1C is linked to MSX I/O port #71
</Unconfirmed data found by looking at ROM dump>
Gallery
Links
- Toshiba TMPZ84C015AF-6 Z80A microprocessor (English)
- Sharp LH0081A Z80A PIO Parallel Input/Output controller (English)
- MCM 53 page 59 listing combined with MCM 51 page 17 and 18 listing (Dutch)
- ASCII MSX Magazine 1990/07 page 77 hardware initialize and sound format (Japanese)
- ASCII MSX Magazine 1990/08 page 59 - 1 use track setting, 2 send data, 3 send data check (Japanese)