Midi, serial ports, uart's and the compaq aero

[Rene Schmitz]

Hi Colin,

This discussion made me thinking if I can improve my interface.I want
something 
like 16 CVs for the start. So I've indeed some questions about your interface.

How long do you sample the value from the dac into the S&Hs? 

Is there a way to put all of the outputs of the 4051 into a high impedance
state?

I think the load on the parallel port is not so critical, I would update at
every 
received midi message (clock pulses at 24ppq...). The S&H tilt must not be
too high then.
I maybe get away without a processor, but can't use the unit standalone. 
If one takes the slow midi interface with its 31.25Kbaud then a single byte
takes 320us to transmit, now even with a 2us sample time for each output
one can theoretically  update 160 outputs into the same time interval. 

Bye
 -René 


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