re-coding Synth ROMs ???

[David Evans]

john.. wrote:
> 
> Hi,
> 	I've seen various people discussing third-party software upgrades
> for old synths (ie Encore Electronics).... how do people go about working
> out what the code does?

  You get the service docs, pour over the schematics, try to figure out a
memory map from the CPU's point of view, and then have at the code with a
disassembler.  I suppose ideally you could ignore the original code and write
your own from scratch.  I know this is what JD and Neil did for Europa, but I
also know that they thoroughly dug into Roland's code as well.  Whether this
was because they figured they could improve it (they decided it was better
scrapped), or because they needed hardware info not available from the schems
I don't know.

> I ask because I'd really like to modify the
> behaviour of my OSCar (give it a better MIDI spec etc.).
> 

  Well, at least Chris Hugget (sp?) is sort-of around still.  Maybe someone
could get info from him?

-- 
David Evans              (NeXTMail OK)              dfevans at bbcr.uwaterloo.ca
Computer/Synth Junkie                      http://bbcr.uwaterloo.ca/~dfevans/
University of Waterloo         "Default is the value selected by the composer
Ontario, Canada           overridden by your command." - Roland TR-707 Manual