At 11:17 AM 05/11/2000 , you wrote:
>I am working on a  old 486 board. This was one is probably circa 95-96 and
>has a AMD486DX100  in it. There are two 72 pin simms  being used and four
>30 pin simms slots unused. As I recall dual simm slots and pin adaptors
>were pretty common back then so that users did not have to get rid of their
>old 30 pin simms.
>
>Does anyone recall if it was common to use both 72 and 30
>simultaneously...or were there particular requirements that had to be met?
>....or was it depends on the board ? What were the issues ?

It usually depended on the motherboard, the manual for the board will
give you instructions on how to fill the slots, (you should be able to find
the manual on the manufacturers web site).

Those boards allowed for one 72pin simm in a slot, but the 30pin simms
must be in matched sets of two each.

You will need to insure that all the memory is either parity or non-parity.
This can cause some issues also.   You should also remember that the
30pin simms typically are much slower than the 72pin chips and will slow
the entire system memory to the slowest speed.   Generally, you can add
30pin simms and 72pin simms on the same board, as long as you follow
these basic rules.

        Bob Wright
The NOSPIN Group

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