The Pill - Question - Atari 8-Bit Computers

The PILL was nothing more than a set of ram chips on a cartridge, with a switch controlling a write latch. Basically, the Atari 8-bit systems according to their memory map, only have 16K of address spacmemorye in which to map cartridges.

On the Atari 800, there were two cartridge slots which mapped themselves into 8K segments, the left cartridge taking up the lower 8K, the right cartridge taking up the upper 8K. However, there are enough address lines on the left cartridge slot to allow the Left cartridge slot to map the entire 16K address space for itself, (this also means you cannot use a Right cartridge when a Left cartridge is present.) It was this feature that ultimately led Atari to simply get rid of the Right Cartridge slot, and honestly given the lack of usefulness of the right cartridge slot (I know of 9 cartridges that actually used it.) I don't think many missed it. (ok, there were those of us with Monkey Wrench Carts that were pissed :-( ) But I digress.....

Basically, there is only 16K of usable address space at the cartridge slot. If you want more, you have to employ a bank-switching technique to move other 16K segments of RAM into the visible 16K address space, and since there was no de-facto way of doing this, everybody did it differently. (I rather liked the OSS MegaCart bank-switching technique.. it used a lot of 7400 logic, but it mapped 16K carts into 8K of address space..which REALLY made BASIC XL very compatible memory-wise with the original ATARI BASIC.)

THE SHORT ANSWER HERE:

There was no feasible way to cram every known combination of logic gates to employ every known form of bank switching in use at the time. Hell, there were only a handful of carts that employed bank switching at the time The PILL was released (1983).

However today, you could use any number of programmable logic arrays to implement bank switching techniques needed by a particular cartridge.

-Thom