Lessons wanted

[jwilmin at hzsbg01.nl.lucent.com]

Hi,

Can anyone out there teach me some lessons on voice updating. I'm getting
a little confused lately (well, I'm also getting older of course)

Its about (voice) updating of polyphonic synths (of the 80's).
The keyboard used to be scanned about once a millisec, and, If I remember well,
the voices would be updated with a rate of one voice per milllisec. So, for
an 8 voice instrument, all voices would be updated after 8 millisecs. Then
the cycle started again.
Now I heard that the Chroma updated its voices every 20 millisecs. Now that
sounds slow to me, or are my expectations set too high ?? Also this synth has
sw controlled envelopes, which means that also these envelopes would be updated
every 20 msecs. That means (according to my theory, but I might be wrong) that
the minimum attack time for instance also is 20 msecs. Am I right?  Isn't this
horribly slow, or did I miss something.

What would be a 'good' rate of voice updating ?

Hope someone of you has some time and minds to help me out here.

Greetings
Janwillem Wilmink