[sdiy] pd650 - do all the Roland applicaitons use an identical chip?

[Colin f]

> The 303, the 606, the 808 etc. etc. all list the pd650c as 
> their (now unavailible) microprocessor.  Can these be 
> interchanged between units, or are they specialised somehow 
> for each individual application?

These devices are mask programmed.
The firmware is on a 'ROM' on the chip, so each CPU suits only the unit it
is meant for.
They have an extra number on the IC to indicate what mask it is programmed
with.
I don't think you can read the code out either...
I got a spare 606 CPU from Rolan not too long ago.
I don't think they have any 303 CPUs left anywhere.
Never checked on the 808.

Cheers,
Colin f