Memory Upgrade

[Joseph Knapka]

David Chow wrote:
>Vernard C. Martin wrote:
>> I have 16 1 MB 30 pin Simms. I want to somehow get them converted to either
>> 4 4MB 40pin simms or better. I've heard of places that will resolder the
>
>	Another thing you might want to look into is those simm holders that 
>  allow you to "piggy-back" lower capacity simms onto one simm.  I've
>  never tried it before.  Has anyone here tried it?
> 

Yes. I have 16MB of RAM on my machine. 8 of it is in 72-pin, 60ns SIMMS;
the other 8 is 1MB, 30-pin, 80ns SIMMS, piggybacked onto a pair of SIMMSaver
30-to-72-pin converters. I have never had any trouble at all with this
arrangement, under either Linux or WINDOG.

The only potential problems are form-factor issues. These things need a
lot of vertical clearance over the motherboard - 2 to 3 inches. They are
basically daughter-cards that fit in the 72-pin slots, and allow you to
attach the 30-pin SIMMs horizontally:


                          SIMM1-| |-SIMM5
                          SIMM2-| |-SIMM6 
                          SIMM3-| |-SIMM7 
                          SIMM4-| |-SIMM8
=============Motherboard============================= 

Unfortunately, if you have a 4-slot bank, you can typically only use
two of the converter modules, since the 30-pin SIMMs extend over
the adjacent 72-pin slot. Furthermore, you need to get one "right-
handed" and one "left-handed" module, or they will not fit next to
one another in adjacent slots.

The good news is that there IS room for a regular 72-pin SIMM in the
slot next to the converter module - the first 30-pin is far enough
off of the motherboard to allow that. However, I've seen machines
where the placement of power supply, drive bays, etc. precludes the
use of the converter modules, simply because there's not enough
vertical clearance for them. Be sure you have the space before you
order anything.

Good luck,

-- Joe