My next PCB: a sound card for my 6502 system. I'm setting it up for the potential of four programmable sound generators, but only two would need to be populated. With all four, stereo audio with six subchannels would be possible.

The PCB is a four-layer PCB with inner planes for VCC and GND. The card will require power and two full VIA ports to be supplied.

I'm including two EEPROM ZIF sockets. Neither EEPROM would need to be populated. The PCB will support zero, one, or two EEPROMs.

As the PCB sits now, the per PCB (unpopulated) cost is approximately $10 USD.

What am I overlooking? Suggestions to improve the design? Let me know! Thanks!

Note: The latest revision is at the bottom of this posting.

Postscript

I updated the schematic to split the EEPROMs between set 1 and set 2 of the PSGs. No glue logic needed.

PPS

After some cleanup, here's what I have. I think this is pretty close to being ready to order.