Not every motheboard that says doesn't support EDO ram will work with
EDO RAM.  I have tones of 486 board that cannot even see the existence
of the EDO ram.  For the motherboards that claim do not work with EDO, there
are SOME that will take EDO and work correctly, there are SOME that will
take EDO and has lots of glitches when the system runs, most of them
don't work with EDO.

So, the only one way to see if your computer can accept EDO or not is to
get a pair and try.  Personally, I won't even bother to try to get EDO
and try and see if it works or not (unless I can get a pair for free.)
Because if it doesn't work, I need to go through a whole process of RMA
for credit or exchange; or if unfortunately, the RAM got damaged when I
am testing (it could be damage before I got the RAM,) I can even lost
more money on the expansive test.  Just get whatever the menu recommend
and forget about if the computer can take EDO or not.  It does not cost
too much more.  By the way, I would personally suggest you to get the
memory from larger memory maker, like Kingston...  They have a very
complete reference that should almost guarantee that the memory will
work in the equipment.

good luck,
Constance Chang

> On July 20, 1998 John Rinehart wrote:
>
> To go back to the original question that I asked, I would like to upgrade the
> memory on an older Packard Bell system.  The system has an AMI MB and BIOS.
> The chipset on the MB is an Intel Neptune chip set 82433NX (LBX), 82434NX (PCMC)
> , and 82378ZB (SIO.G).
>
> Information in Packard Bell's WEB site states for this system PB550:
>
> 1. SIMM speed must be 70ns or faster.
> 2. The SIMMs are 72-pin and can be x32 or x36. The motherboard design does not
> require parity checking  The motherboard will not use EDO,
> only Fast Page Mode SIMMs will operate correctly in this motherboard.
>
> And yet Scott Mueller's Upgrading and Repairing PC's states on page 803
> paragraph 2 of the 8th edition, "You can install EDO memory in older systems
> that do not support it because EDO is backward-compatible with standard (called
> fast page mode) memory."
>
> Sincerely, John
>