I have an APPLE II+, and I have a DISK ][ card. I have heard that somebody once developed a card that uses a soft-switch to swap out the ROM for some more RAM, giving the system 64k of RAM in all. I've seen cards for this on eBay, but I don't feel like giving someone an arm and a leg just for my Apple's sake. So here's my question, has anyone here built their own RAM expansion interface? Theoriticaly, one would only need a 74LS74 D-Type flip-flop, and the RAM chip. I think I might be able to expand my apple's memory for a very little bit of money, but I'm just not sure how to do it. So if someone who's done this could give me a schematic, or a detailed explanation, that would be greatly appreciated. I'd rather sweat than pay at the moment. 
~Mark Baldridge
Am I reading that your 48K RAM Apple II+ does not have a 16K RAM "Language Card?"
The "language card" is the 16K memory card that goes in Slot #0, and usually has a ribbon that goes into where a 2K RAM slot in order to get the RAM refresh. It also has soft switches to select the various banks of ROM/RAM and read/write settings. The 12K RAM and ROM are addressable from D000-FFFF, and an extra 4K RAM is bank switched from D000-DFFF in memory.
If you are looking for even more memory, there is a RAM card on ebay still in the shrink wrap.
Ok, thank you. Yes, my Apple II+ does NOT have a 16k RAM "Language Card".
Thanks