9 Jun
2004
9 Jun
'04
12:13 p.m.
Tony Duell wrote:
So I talked to the memory guy here, and he says that the MT part
number is bogus. He says that there was a company doing counterfeits in
the late 80s and these are some of them.
Back to the DRAM nomenclature, the 1 bit vs 1 byte explanation helps
a lot. I'm still confused about the multiplier.
The Amiga docs show 16 256Kx4 DRAMs for a total of 2MB, so does that
mean that these chips are 256Kx1?
Doc
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