story of Mel

allison ajp166 at verizon.net
Thu Feb 23 10:04:15 CST 2017


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.


Allison


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