hmmm, I
thought there were four rows of 18 chips.
That sounds like 8 banks of 256K which seems
like 2meg to me... unless I got something wrong
No, I guess I got it wrong. I thought you meant 256K
per chip, or 4MB per bank (16 * 256K plus 2 * 256K for parity).
So are these 256K per bank, or 256K per chip?
The _chips_ are 256K by 1 bit. You feed an 18 bit address into
one chip and you get one data bit out. 9 chips form a bank with
8 data bits plus a parity bit.