ZX96 Megabyte Card
The ZX96 Megabyte-Card
This additional card enlarges the memory up to 1 MB (1024 Bytes!) of the ZX96 or even any other, usual ZX81!
The address range is decoded from 49152 to 65535. So thus will result in max. 64 banks (or pages) of each 16384 Bytes. With a simply POKE 9,x instruction the actually bank will be selected, where x is from 0 to 63. There is space for eight RAM-chips of each 1Mbit (128k x 8). So each chip contains eight banks. The PCB is designed that you also may place less than eight chips, or only one 128k x 8 RAM if 128,000 Bytes are enough. Also, with a small modification, you may place 32k x 8 chips, they are much cheaper. Thus will give max. 256 kBytes and may satisfy the most needs too.
Another possibility is to enlarge the capacity up to 4 MBytes by placing the (expensive!) 512k x 8 chips. I haven't tested it yet, because the chips are too expensive to me.
Adress decoding includes the /M1-wiring so that only data can be stored on the megabytecard. Machine programs cannot be run there!
Kai Fischer, ZX-TEAM, mailto: kai.fischer