7 Mar
2001
7 Mar
'01
11:10 p.m.
On Mar 7, 7:59, Gregory R. Travis wrote:
Thought about that too but the math doesn't work.
40+64 chips = 104
chips * 65536 bits per chip = 6815744 total bits.
6815744 doesn't divide cleanly by any of 9, 18, 19, 36, or 38
It divides by 13, though (64K x 13 x 8, so the prime factors are 2 and 13).
Unlikely as it sounds, could this be for a 12-bit word machine?
13 is not only 12+1, it's 8+5. 5 is a common number of bits for ECC
(though not, I admit, for 8-bit words! Usually it's 8+3, 16+5, or 16+6).
It also strikes me as odd that a NatSemi board should have TI chips on it.
NatSemi made their own RAM, and Texas made their own PDP-11 and Vax memory
boards.
--
Pete Peter Turnbull
Network Manager
Dept. of Computer Science
University of York