Re: Ram questions

[Davis Johnson <davis frizzen com>]

Hoover, Tony wrote:

> Sorry for being late on this, but...
> Make sure that your using "TRUE PARITY" SIMMs/DIMMs.
> I once bought some memory for my EB64+ only to find out that there was such
> thing as "Logic parity" SIMMs.  
> Rather than having a memory chip for the parity bit, the SIMM had logic to
> generate what the parity bit should be.  Alphas can't handle that type of
> memory.
>  
If you can examine the SIMMs (or their pictures) you will notice that 
they will have a number of identical chips and sometimes one or two 
different chips. The identical chips are the actual memory, the 
different chips are either glue or fake parity.

SIMMS with a multiple of 4 or 8 memory chips are probably non-parity, or 
possibly fake parity if there is a non-memory chip on the SIMM.

SIMMS with a multiple of 3 or 9 memory chips are probably true parity. 
These are what you are looking for.

These rather crude rules are imperfect, but have been helpful for me 
while trying to find memory to work in my AS200.