pvtjokerdavis wrote
I've been trying to figure out how the addressing will work for the Memory chip. I understand that the two
most significant bits, address[13] and address[14] can be used to determine which part of the memory
should be accessed. But it's confusing because the RAM16K chip accepts a 14-bit wide address input, the
SCREEN takes a 13-bit wide address input, and the KBD register doesn't have an address input. The Memory
chip as a whole takes a 15-bit wide address input. Is the configuration similar to that of the RAMs? Feeling
confused
Yes, Memory is the same general idea as the RAM chips, but the address space for the sub-components consists of different sized blocks. Just hook the matching number of low order address bits to the RAM and Screen and control their load based on the upper bits. All three parts are always generating outputs, just like the RAMs inside a bigger RAM, so you also need to use the upper address bits to select which part's output gets sent to the Memory's output.
--Mark
Locked
