Hi Kent!
Sorry for the late reply- I just saw this!
So, I briefly looked into a cassette interface. Designing and making a cassette interface should be easy- as the Apple 1 Cassette interface would serve as a great model- the ROM chip they used is NLA, but should be easy enough to replace with a modern device. And, I've already got the firmware, and it's already documented how to use the interface with the Wozmon monitor we're using. However, the original interface would require -12 volts. Either we'd have to rig up something that sits on the cassette interface and uses/converts the 5 volts from the expansion socket of the PE6502(if possible) or a ATX power supply would be needed. Then, there are reports that the cassette interface never really worked super reliably anyways- but that is another story.
I need to double check with the guy who makes/sells the CFFA1 interface. A few months ago I gave him data from the PE6502, and he said he would adapt his product to work with the PE6502. I'll have to make an adapter (from the PE6502 expansion header to a socket that will connect to the CFFA1 card) but that would be useful to interface any other Apple 1 card with the PE6502. The CFFA1 is essentially a "hard drive" for the Apple 1, Replica 1, and PE6502, which uses a compact flash card as mass storage, and will allow a HUGE library to be available at all times.
I'll email him tonight, but in the mean time, you can read up on the product on his website:
http://dreher.netDo you guys have any other ideas? Would a floppy drive be desirable? Or something else?
Happy to hear your enjoying your PE6502!