sean@garfield.UUCP (06/01/83)
This should belong in fa.bitgraph but this isn't ARPA,
So...
What has anyone does with the BBN Bitgraph's sound
chip? I have written a music interpreter language for example:
Ab 1 C# 2.
indicates A flat for a full note and then a dotted
C sharp for a half note. It has settable tempo, volume,
and a range of 9 octaves. I have tried do something with the envelope
generator, but this is too brain-damaged. One problem with
my program is that I only use one of the three voices as there
is no way to specify duration for each tone generator. Three
voices can operate at once, but there is only one duration.
The way I determine the length of a note is by using the
Bitgraph's internal clock specified for a number of millisecs.
The only other way I can think of doing this is to set
the generators going for infinity (0 duration) and then zero the volume
register after the duration of the note. This isn't very
regular, depending on how slow the system is. I have considered
using the internal MC68000, but don't know if this is worth-while.
I would appreciate any comments or ideas. We do have cc68, ld68
etc. but don't know how well this works (it is the original
version that came with 4.1). My current version uses only one
voice and the Bitgraph's clock to do timing. This works
pretty well but the Bitgraph spazs a bit when playing very
fast. (eg during Mozart's Enie Kliene Nachtmuzak it drops
a few notes). It is the Bitgraph Version 3.10. with 1/2 Meg
of memory. Also what have people got for printing/composing/
inputing musical notation? And for what devices using what
packages. We have an implementation of the Core system (basic,
no-input, 3d). I would appreciate any information people have.
Sean Byrne
{allegra,utcsrgv}!garfield!sean