ebay Altair Music Record

From: cswiger <cswiger_at_wilma.widomaker.com>
Date: Mon Dec 7 09:54:12 1998

>The main hardware used was an ALTAIR 8800A Computer
>(INTEL 8080 chip). The software was an MITS Package
>I Monitor, enhanced with JAMON (written by Jerry A. Ford,
>MITS Program #117752). The synthesizers consist of 3
>identical voice circuits (pictured on the front of the
>album cover).

This is an Altair controlled hardware synth I take it?

Now *MY* Altair Synth (pardon the ego!) was all done in
software, with a simple 8-bit d/a converter on an i/o
port. It used 256 bytes of a waveform (fundamental sin(x)
plus some harmonics) that were stepped thru by up to
4 pointers at various rates and added up to get 4 part
harmony. Took a lot of instruction cycle counting to
get the timing just right and was worked up to where
one could, with a lot of tedious data entry, type in
a Bach invention (#8 - was on 'Switched on Bach') and
have it play perfectly. Now, being a 2Mhz machine it
sang bass and tenor mostly.

Spent many a long night getting one together for a
school software contest and the prof. gave the prize to
a lousy serial auto-baud detector (probably because HE
suggested it). So we learned that demo's need BIG
speakers to make an impression :))


A# = (12th root of 2) * 440Hz
B = " * A#


        Chuck
        cswiger_at_widomaker.com
Received on Mon Dec 07 1998 - 09:54:12 GMT