I have a problem for homework that has me stumped. Basically, what I'm given is 2 R/WMs, each 2048 bytes * 4. Connected to each of their CS pin is a NAND gate with pins A12-A15 connected from the 8085 microprocessor. The CS pins of both modules are in parallel with the gate. The RD and WR pins of each are connected top MEMR and MEMW. The pins of the modules are connected to A0-A10 of 8085 microprocessor. A11 is a don't care at logic 0 (I have no idea what this means).
The problem asks to identify the memory addresses. I've determined based on the NAND gate that the range would be from F000 to F7FF. This is where I'm stumped. First of all, that's a range of 800. Since that's in hex, I would think that gives only a range of 2048 bytes, which doesn't seem right. There's a total of 16k between the two modules, so something seems to be wrong.
I would think my problem is with the high order bits, 12-15 which go through the NAND. Could someone point me in the right direction? I've included a diagram of the problem below.