Akai S1100EX 16 Voice Expansion Unit for the S1100 (part 3)
Faster Than MIDI - SCSI
We are by now very well used to pieces of musical equipment talking to each other along pieces of wire called MIDI cables (I wonder what they say about us?). But MIDI has always been, and always will be, a very pedestrian interface. It takes whole milliseconds just to pass the simplest of messages for goodness sake! How long this situation can last I dont know. Professional and other serious users have been straining at the leash ever since MIDI sequencers and the bits and bytes of the MIDI signal have almost been bursting out of the cable in the rush to get to the other end. Making a faster interface is perfectly possible, but unfortunately its bound to cost more and cannot be compatible with low end users for whom ordinary MIDI is good enough. Nevertheless, there is another standard which is becoming more and more of interest to users of high tech musical equipment - SCSI, which stands for Small Computer Systems Interface, if you didnt know by now. SCSI is altogether better and faster and one day, I predict, will engage in a wonderfully productive relationship with MIDI and sequenced music making will take a giant leap into the future.
The S1100 and S1100EX use SCSI to communicate with each other, transferring sample and edit data very quickly. The SCSI standard allows for a total of seven different SCSI devices so the first thing we must do is connect up the system and make sure the SCSI settings are correct. Figure 1 shows the MIDI and SCSI hook up. The MIDI cable goes, naturally enough from the THRU connector on the S1100 to the IN of the S1100EX. The SCSI cable goes from the single SCSI port on the S1100 to the top SCSI port on the S1100EX. If you really are wealthy and have more S1100EXs, then the second SCSI port can be used to daisy chain extra units.
To use SCSI successfully you need to be aware of technicalities like SCSI ID numbers and terminators. Now in case you thought that a terminator was a nasty machine sent from the future to get you good, a SCSI terminator is simply a means of telling the SCSI controlling software where the end of the daisy chain is. If you have only one S1100EX, then the termination switch is set to On. Since there can be up to seven SCSI devices on the daisy chain, each one needs an identification number exactly analogous to identifying instruments by MIDI channels. The S1100 and S1100EX have preset ID numbers so that in their factory fresh state you can connect them up and start work, but if you are adding to an existing SCSI system, or someone has been fiddling, then you have to make sure that each is set to a different ID number. The manual makes all of this perfectly clear, although I suspect when computer technology is applied to musical instruments more than it is now, the difficulties will multiply.