[sdiy] rackmounting keyboard synths...

[Rainer Buchty]

> a question to anyone who has rackmounted midi-based keyboard synths...
> are there usually any problems caused by removing the keyboard
> assemblies from synthesizers? or will the keyboard scanner/matrix
> [unless it can also be removed/is on a separate board from the
> midi+synth boards] just assume that no notes are pressed?

It depends.

For example, the Casio machines I have treat a disconnected keyboard as
"no keys pressed". Dito for the Ensoniq ESQ-1. For the SQ80 (and possibly
all other polypressure-keyboard based Ensoniq machines) you need to still
attach the keyboard processor (cause it's part of an internal
communication chain); while this keeps the comm chain up and running, the
keyboard processor will though report a persistant failure calibrating the
keyboard. The OS can deal with that, but (w/o OS alteration) requires user
interaction.

> [by the way... don't worry about me hacking up any synths that are too
> sacred... a person only has room for so many [full] keyboards, and i might
> be getting a few mid 80's midi synths over the summer, since apparently
> nothing easily available from the 80s is worth over 200 dollars... or at
> least thats what the shops say, but sentiment speaks otherwise, i mean, look
> at the dx-7]

So far I came across the following methods how keyboards are integrated in
1980s machines:

- standard row/column scanning using arbitrary port ICs mapped into the
  main processor's memory space (e.g. Casio CZ-101; I wouldn't expect any
  oddities with these

- separate keyboard scanner and controller mapped into the main
  processor's memory space (e.g. Casio FZ-1); removing the keyboard
  shouldn't cause harm as well

- separate keyboard controller in a serial communications chain (e.g.
  Ensoniq machines); problematic if the keyboard controller alters
  incoming data

HTH,
	Rainer