Hi Dieter

> Sounds interesting for me too. How should the input of the notes be
> managed - if not via Midi (e.g. with several CV inputs) Or is Midi the only
> option from your point of view Or a separate keyboard just for this
> function (e.g. with small buttons only, like the buttons used in the A-107
> or A-113)

The hardware solution (separate keyboard) would be kind of "analogue
sexy" :-). There are also some other tricks, that could be done with
such a keyboard.
But I think the (economically) best noteinput would be midi, because it
would make the module also usable standalone for other (non modular)
users. Also such a PIC or uP based module could be extended without a
problem to a single track sequencer (you remember the SH-101 sequencer I
showed you some years ago ).

For the technical side:
I don't know how MIDI arpeggiators are programmed in detail, but I
assume, that there is a buffer which is a mix of a fifo and an
addressable memory.

Since we do not have a real addressbus to modify (everything is handled
within a PIC or uP), there should be an external Dataword which can be
set manually. This data word is digitally AND'ed with the uP-internal
address that reads the buffer.
The external dataword could be four or more switches, which give 0 or 5
volts, and a corresponding count of input sockets, that are read as
binary (eventually with comparators, so one could use continuous control
voltages as input).

Florian