[rescue] SS2 memory?

[George Adkins]

On Wednesday 06 March 2002 09:40 pm, you wrote:
> On Wednesday 06 March 2002 09:18 pm, you wrote:
> > > 1.  The original 4M sticks in this machine consist of 9 chips and the
> > > ones I just added consist of just 3 chips.  What does this mean and
> > > what are the ramifications?  (ha)
> >
> > Run! Run Screaming!  The 3 chip simms will only give you pain and
> > heartache...
>
> <5-year-old-son look>
>
> Why....?
>
Many of the 3 chip 30's were intended as PeeCee parts in the days when the 
clone stuff was even poorer in quality than it is today.  Many of the Boards 
did not use or even check the parity bit on the memory, so _some_ memory 
makers (the cheapest ones) simply took shortcuts and used really lousy chips 
for the parity bit, (counting on the fact that they'd never get used much) or 
'faked' it with 'logic parity', where the third chip actually /dev/null's the 
incoming parity data and then during reads, generates the parity bit on the 
fly, and feeds it back to the system.  (obviously useless for actually 
DETECTING single bit memory errors.)

George