Developing MIDI/SYNC

[Prof. Antonio Guerrieri]

	Hi All,

	I really do not know if the following is a little bit off-topic in
this list, anyway I will try since I think can be of general interest.

	Actually I'm involved in the design and construction of a MIDI/SYNC
device to connect my analogic drum machine TR606 to the MIDI net.

	The TR606 as well as other oXo related machines (such as the
(in)famous TB303 and the TR808) have not MIDI facilities BUT can accept an
external clock as well as other signal commands (all defined as SYNC) for
its control.
 	Both schematics and commercial devices can be found around but
unfortunately they do not fit my purposes (including the money one).
So...DIY.
 	Unfortunately, my knowledge in this field are not so broad hence I
hope in an help by you. I have several problems but I think it is best to
fix a problem at time.
My first problem.

Using a common UART and a bit of logic it is possible to decode/convert the
serial MIDI clock message in a signal clock to be used to trigger something
like a Schmitt Trigger IC: in this way the TR606 is clocked at SAME MIDI
clock rate (f). If I need a lower clock rate, i.e. f/2, f/3, f/4, ... up to
f/16, I think is necessary something like a programmable or better a dip
swicth addressable counter/divider logic IC between the logic and the
Schmitt Trigger IC. There are several ICs that probably can be used for
this purpose but looking at their True or Time tables it is evident for all
that, for example, the master clock and f/2 are not in phase ...something
like the following:

Master clock _i-i _i-i _i-i _i-i _i-i _i-i _i-i _i-i_
f/2	     ___i----i ___i----i ___i----i____

Do you recommend some suitable ICs logic for this purpose (all my logic are
based on the 74HC cmos logic) as well as some schematics? Do you think that
the above feature, i.e. master clock and f/n not in phase can be
deleterious for my purpose? It is not better something in phase like the
following:

Master clock _i-i _i-i _i-i _i-i _i-i _i-i _i-i _i-i_
f/2	     _i----i ___i----i ___i----i____


How this can be accomplished?
Consider, however, that my 606 needs a START/STOP message to begin its drum
pattern (also this encoded in a MIDI start/stop/continue message that is
decoded in a START/STOP signal in the same MIDI/SYNC device but by using an
other logic). Probably, such signal forces both the MIDI and the 606 gears
to start together.What do you think?

End of first help request.

Thank you in advance,

Antonio