Cassette interfaces are going to cost $20-30. On top of that, I haven't had a cassette recorder in years, so I'm wondering about alternatives. My project is something closer to a KIM-1 than an Apple-1 because of the cost differences (I'm working on a college student's budget to design an after school program for kids to build something they can tinker with and teach them how to do so. I may have to provide much or even all of the funding for this program, so a $5 savings in parts is going to be huge..)
Basically, the cassette interface is going to cost so much for something that so few of the kids are going to have access to at home. I mean, there are three cassette recorders in the classroom, but in this day and age you almost wind up wondering how many of these kids have ever seen a cassette before. Most of them have more modern computers at home they can play with, but that isn't going to help them either.
Then I got to thinking about flash memories. I'm already using an EEPROM for the monitor and standard I/O routines, why not another wired up through a simple cartridge connector? Since it effectively looks like non-volatile SRAM with a write protect to the rest of the system, it would be easy to do. Or I could set up, with very little extra hardware, something that looked like a disk controller.
That part about disk controllers got me thinking: as cheap as an 8k EEPROM is, once you have something that you can actually remove from the system via a card connector or something, you're going to have something that costs as much as the cheapest camera flash cards. On top of that, the cards would be readable only by this thing, unless I were to build another interface to connect it to a parallel port. Of course, that would require that I had a parallel port, which isn't standard equipment on a mac.
I'm wondering if it might not just make sense to use a "normal" flash memory device in a multicard reader. SmartMedia would be the most obvious choice (though it's getting kinda rare) because it's about as simple as the EEPROM, but perhaps CF is a reasonable consideration? What I'm pretty sure, at this point, is that supporting any form of FAT on such a memory card is more trouble than it's worth. Still requires "special" software on the host-side, but UNIX and MacOS X would be easy--I'm not sure about Windows offhand.
Are there other ideas I'm not considering? Any suggestions or ideas? Since I don't have an existing DOS (or at this point even a monitor), I pretty much have all of the options and none of the limitations for the time being.