RS232 in Titan

[WeAreAs1 at aol.com]

On Wed, 23 Apr 1997, Paul Schreiber wrote:
> Trivia: How was the MIDI data rate selected?
>
> Answer: It was the fastest baud rate an Intel 8751 with a 12Mhz crystal
could go!!

I always thought that MIDI's 31.25 kHz baud rate was chosen because it was
easy to arrive at that number by simply dividing a 1 mHz clock down (in
multiples of two).  1 mHz divided by 32 is 31.25 kHz.  This is also what I
was told by J. L. Cooper back in 1984 (when he, as head of the MIDI
Manufacturers Association, was part of the handful of people who were
defining what MIDI was to become).

I guess they could have chosen 62.5 kHz just as easily (for the same reason),
but back in those days, the speed that the then currently available
optoisolators could reliably clock data was also an issue.  They were trying
to design an inexpensive no-brainer system that would always work, even in a
worst-case scenario.  Today's opto's can run reliably at much higher clock
rates than the Sharp PC900's that were so popular back then.  Factors such as
cable length and cable capacitance can make or break a reliable MIDI
connection, even at 31.25k.  I imagine that Dave Smith, et al settled on
31.25k after testing the system out at higher clock rates.