I’m also the proud owner of one of these. With the help of Richard Factor I got hold of a service manual which was enough to fix the few chips in the unit that were causing chaos. However having sorted out the delays I still have an issue with the Harmonizer for which my manual has no details as it was a later addition. Nick do you think I could trouble you to ask the designer for any schematic or info on the Harmonizer? It’s more than just a slight variation on the delay despite running on the same Read/Write and Address system.
Thanks for your comments! I haven’t seen a schematic for this module in decades. Assuming one has survived, it will only turn up by accident during an aperiodic cleanup, and then only when the pandemic is resolved.
My only memory of this product was the general way it worked. A variable oscillator controlled by the front panel knob clocked the output of an exotic, now- (and possibly even then-) obsolete FIFO chip at up to 2x the sample rate. The chip had a “half full” flag which triggered TWO reads of the memory, for which there would be plenty of room in the FIFO. Depending on the output sample rate determined by the knob, you could get up to a 2x pitch increment. The rest of it was probably similar to the standard output modules.
Good luck on your somewhat quixotic quest. BTW, anyone else looking for the 1745 manual should check out this under-construction, messy, inaccurate, and very incomplete page: http://priups.com/manuals.htm
Richard
Thanks so much for your help, Richard. The quest will continue. Have a great weekend!
Lincoln
