________________________________________
From: cctech [cctech-bounces at
classiccmp.org] on behalf of allison [ajp166 at
verizon.net]
Sent: Thursday, February 23, 2017 11:04 AM
To: cctech at
classiccmp.org
Subject: Re: story of Mel
On 2/23/17 3:23 AM, Pontus Pihlgren wrote:
On Wed, Feb 22, 2017 at 02:18:50PM -0500, allison
wrote:
The sound (not music) card was actually a
internally built and not sold
(that I know of).
There must have been a few though, since several claim to have
one and
it even showed up on ebay.
(I'm just hoping I'l get lucky and find one.. I have an 11/73 with
graphics, it would be nice to add sound to it)
/P
Last time I needed just a beep it was the DTR line on the async card
being flipped
by a simple loop. If you flip it and leave it you get a click....
Obviously you need
an amplifier(maybe or a transistor) and speaker to hear it.
The sound card I have is not part of the OS (any) and there is no
support so it does
nothing without code and a d/a or even a few bits will do sound.
FYI there was many articles in the micro world on doing sound and music
in Byte and DDJ back when (1975 to mid 80s) in the time before PCs and
sound cards. For example Processor Technologies Music system.
See
http://www.sol20.org/manuals/music.pdf for the manual on that.
I believe it was Polymorphic systems that did a polyphonic sound system
for z80 computers.
Those are samples of interest connected with computer music back then.
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I always thought music in the old days was more about MIDI and letting
something designed for it do the work ala Usenix Nashville 1991.
bill
To you that's the old days. To me its recent history.
Midi became the common bus to talk to instruments and drivers
(keyboards, synthetic strings and all) of
all sorts. It popped up in the early 80s as a viable bus for music and
stage control IO.
Before midi... when dirt was relatively new then, we used computers and
software to do things like
flip the PDP-8 link bit and a speaker attached. Fancy would have been
a R2R of 5 or 8 bits as simple
D/A on a parallel output port (or LP11) and with the right timing loops
and maybe some data you could
synthesize any waveform and most any pitch. if the machine was fast
enough. Of course you need a
music input too and something to compile it to data and commands (or did
it using a #2 and paper).
There was a major conference in the 70s for computer generated music.
Look up NOTRAN.
Allison