[comp.sys.mac.hardware] SID Update!!!

mikec@wheaties.ai.mit.edu (Mike E. Ciholas) (05/08/90)

Greetings SIDers!

[if you don't know what a SID is, download info-mac/sound/program/sid.hqx
from sumex-aim.stanford.edu, its a sound digitizer for the Mac]

There defintely seems to be enough demand for a PC board, so that will
defintely happen.

There is some confusion over the SIDs capabilites.  It does NOT do stereo
by itself.  It MAY do stereo if you have two of them hooked to two serial
ports but the sounds will become unsynchronized eventually (no time base
can be that accurate).  So, if anyone was getting a SID for stereo, don't.
(I am considering a stereo version, so stay tuned...)
(I also have plans, get this, of making a VIDEO version!  If you would like
that, let me know!)

I have changed the timing, power, and filter sections.  The timing section
will now accept a variety of crystals and resonators (including the
original ones).  Some standard crystals produce very close results (A 6.144
MHz crystal is off by only 280ppm when divided by 23 and with a 12 state
conversion).

The power section has wider voltages for the op-amps and better filtering.

The filter section is still in the process of changing.  I have eliminated the
1uF caps (over 2 stinkin' dollars just for them!).  I may add one more
set of op-amps.  A complete schematic, layout, and parts list will be made
available free of charge to anyone (it will get posted to sumex, someone
tell me how to do that, please?).

It won't be long now...

Mike Ciholas

mikec@ai.mit.edu