On Mon, 30 Dec 2002, Wilko Bulte wrote:

> On Mon, Dec 30, 2002 at 11:58:59AM +0100, Pavel Cahyna wrote:
> > > I think, Suns don't use 33bit in general, i didn't try this, but i think, the
> > > SparcStation ELC/SLC needs 33 bits, other machines may need 36 bits. Alphas
> > > sometimes need 33 bits (AlphaStation 200?), sometimes 36 bits (Multia?
> > > AXPpci33?)
> > > 
> > > I never tried in detail, but as a rule of thumb:
> > > 
> > > 33 bits are hard to get. 36 bits are easier to get.
> > > 36 bits run nearly everywhere, except some rare machines needing 40 bits.
> > > I'm using the standard 36 bit modules in Alpha, Sparc, IBM RS/6k, SGI and lots
> > > more here.
> > > 
> > > HP Modules (9000/700 series and some newer 400s) are also 36 bits, but be
> > > careful here, they just look like PS/2 but have a slightly different pinout and
> > 
> > Like PS/2? Do you mean that IBM PS/2 have their own type of SIMMs?
> 
> The 72pins SIMMs were first in general use on PS/2 AFAIK. That is why
> they are commonly refered to as PS/2 SIMMs.
> 

I do recall at the back of my mind, fitting some 72pin SIMMS to a PS/2, 
and finding that they did not work.  In the end had to fiddle with the 
Presence detection pins (the eight soldier pads, normally on the right 
side as you look with pin 1 on the left); to get the machine to detect the 
correct amount memory.

I might have also had to do this to get such memory to work in the Sun 
IPXs as well...

Dave.