[sdiy] Casio MT rhythm sync

[Adam Inglis]

Has anyone managed to sync the rhythm generator on a pre-midi Casio  
to external clock?

I have a MT400v  which has rhythm and auto-bass/chord elements that  
can be routed thru a resonant analogue filter, making quirky squelchy  
funk!  But my examination of the gubbins with a scope (no schematic)  
and reading the links in recent posts has me scratching my head as to  
where the generated patterns are coming from.
There are two main chips in this thing (similar to other MT keyboards  
from this period, about 1982 I think) - the NEC D930 and the D931.  
The tablehooters site describes the D930 chip as an "accompaniment  
CPU", and only gives a partial pin-out. Robin Whittle describes the  
D931 extensively, it would seem to be the main voice generating chip  
but I cant see that it contains the drum sounds or the patterns.
The "tempo" slider seems to see a high-frequency sawtooth with  
variable DC offset 1-5 volts.

I don't have much experience with digital stuff so there is prob  
something obvious I'm missing - if it was possible I'm sure I would  
find something via Google but no luck!


regards
Adam Inglis
http://www.adambaby.com