brad@kontron.UUCP (Brad Yearwood) (01/27/86)
If you are a DX7 fan into tweaking, major hacking, or just plain better understanding, you should look at the following technical information available from Yamaha: SM 150 DX7/9 Service Manual $10.00 Very brief technical descriptions of functional blocks, assembly explosions, PC board layouts, parts lists, schematics for both DX7 and DX9. Parallel descriptions in Japanese and English. SM 174 MIDI Data Format DX7 no charge (only if ordered with other material, probably) Exactly what it says. 3 pages. SM 184 DX7 Test Program Operation $14.00 and Trouble Shooting Guide How to operate the built-in diagnostic program. Includes a few waveform drawings and "if you don't see this, check the following" procedures. SM 200 DX7 Technical Analysis $14.00 Reasonably detailed block-by-block descriptions of the circuitry. Each section gives a fragment of the schematic along with a functional description and some timing diagrams. Has scope photos of various waveforms, and memory maps of the overall system and of the FM synthesis LSI devices. Comes with a reference schematic that may not be the most up to date (see the service manual for production schematics). These are available from: Yamaha International Corporation Attention: MMG Parts 6600 Orangethorpe Buena Park, CA 90620 There is an additional shipping and handling charge of $1.50 per order. They unfortunately accept only cashier's checks or money orders. I don't know whether other manufacturers make this much information available. It's pretty nifty that Yamaha does, and that the parts person that I talked to told me about the other manuals when I asked about the service manual and schematic. My only relationship with Yamaha is as a customer. Brad Yearwood Kontron Electronics {voder, pyramid, loral}!kontron!brad Mountain View, CA