Cheetah Cub board

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Wed Jun 9 18:31:33 2004

> So are these 256K per bank, or 256K per chip? IOW, if they turn out
> to be compatible and I install 16 of them on the Amiga A2091, will that
> be a 2MB or 0.25MB upgrade?

Most DRAM chips are 1 bit wide. A 256K DRAM stores 256K _bits_ (not bytes
or words), arranged as 262144 locations of 1 bit each. 8 such chips store
256K btes, 256K locations of 8 bits each (bit 0 is stored in the
locations of one of the chips, bit 1 in another chip, and so on). 9 chips
were used to store a byte + a parity bit (very common on PCs)


16 of them, used conventionally (which I assume the A2091 does) would
store 512K bytes or 256K 16-bit words. It would be a 0.5M upgrade I guess

-tony
Received on Wed Jun 09 2004 - 18:31:33 BST