Reply 20 of 87, by jmk
'm looking for some old tape recordings of Ps/1 songs I made when I was a little child (yes, I was a crazy maniac), if they are not lost in time, that could help.
Dunno if it can help jmk, I have got some old ibm hardware pieces (one of them is the ps/1 audio/joystick card), I can snap some hires photos of the board front/back and post them here.
I can think of two possibilities (for a partial explanation):
1. I read on an old Sega document that the SN chip has a slight degree of error that can have a slight effect on frequency. (I can't find the document that gave the exact values just now).
2. The master clock frequency is slightly off.
Now, I can imagine that quite a few people on and off this forum would be very interested to see pictures of the audio card! I've certainly not seen any example of it anywhere on the web. (Do you have a Covox Sound Master as well? 😉 )
Another thing you can do is look for the SN76... chip and see the exact model number. Secondly, look for a silver component (possibly with a small x printed on it) which is a crystal. Using the writing on that component it should be possible to work out the exact master frequency.
Many thanks for these things. 😁
Old tapes of computer music... Yes, I made a tape of Sinclair Spectrum music when I was young. 😊