[Info-vax] OT: parity vs ECC on EV4

[John Wallace]

On Oct 19, 8:03 pm, moro... at world.std.spaamtrap.com (Michael Moroney)
wrote:
> John Wallace <johnwalla... at yahoo.co.uk> writes:
> >Wrt AlphaStation 200: what leads you to think it has ECC? The
> >"AlphaStation 200 Series: User Information" book at
> >http://www.compaq.com/alphaserver/download/ek-pcdta-ui-e01.pdf
> >says, in the Motherboard section in chapter 2, "Memory controller and
> >data path that connects through a 64-bit wide data bus to main
> >memory and through a 128-bit wide data bus to second-level cache. The
> >data is longword (32-bits) parity protected. "
>
> The Alphastation 200 used one parity bit to cover each longword (32
> bits) of memory.  It used the then-standard 36 bit 72 pin parity SIMMs.
> Digital even sold 33 bit memory for it for a while.  (was supposed to be
> cheaper because it needed 33/36 as many memory cells, but in reality,
> wasn't)

You know that. I know that. Hopefully Steven will soon be convinced
too. Cheers!