On 01/03/2019 05:22 PM, Kyle Owen wrote: > On Thu, Jan 3, 2019 at 3:29 PM allison via cctech > <cct...@classiccmp.org <mailto:cct...@classiccmp.org>> wrote: > > Those were likely with a PDP12 or LAB-8 with DAC board. The code > actually is a roughly > digital version of tones in 10 or 12 bit form by writing sequential > words (waveforms) to > the DAC. > > > Do you have any information on the AA01-A DAC that was used with the > PDP-12?
No but RICM as a PDP12or two. Worth contacting them and all. They might like a copy of the tapes if they don't already have them. > I see in the PDP-12 System Reference Manual that it is capable of > supporting three channels, 12 bits each. It gives an example of one > instruction, 6551, which loads the first DAC. Is it safe to assume > that 6552 and 6554 are the other instructions to load the other two DACs? > Unknown. > I see the AA50-A in the 1972 PDP-8 Small Computer Handbook has > sequential instructions for updating the DAC channels (up to 8). > > AA05-A/AA07 use a more complex address/data method to address more > total channels, but that is listed in the Laboratory Computer Handbook > as an option on the Negibus. > > Never played with 8s in any form other than omnibus. > Of course everyone here forgets the First Philadelphia Computer Music > Festival on vinyl from '78 > with samples of computer played music. I run my copy on occasion just > to remember being there. > > > I don't think this album has been forgotten; I have a copy, and I know > others with copies, too. It seems as though "Unplayed by Human Hands" > (both versions) are less well-known. I would like to work on getting > the original software archived, assuming it's still out there, as it > ran on a Straight-8. > ITs also on line. Allison
