Re: Adding DRAM to my IIGS' memory expansion board...

[shack@deimos.frii.com (Randy Shackelford)]

In article <19961204095701.EAA27708@ladder01.news.aol.com>,
 <rubywand@aol.com> wrote:
>
>Randall Smith  <tigermtn@i-link-2.net> wrote:
>
>>Help! I've filled my memory expansion board and my GS is still only
>>detecting 256K (512K total, 256K on logic board and 256k soldered unto
>>the expansion board). Do I need to tell the computer I've added the
>>dram? Maybe change a jumper someplace? The dram I added matches the
>>stuff that's soldered on, 41256c 150ns. I can't seem to get to to work.
>>Any help would be great.

Did you put jumpers on the two sets of pine on the card?

>     According to our Memory Expansion Card Owner's Guide, there are two
>recommended upgrades:
>
>512kB (top row filled-- 16 chips):      jumper on lower set of pins
>   1MB (both rows filled-- 32 chips):  jumpers on both sets of pins.
>
>
>     The manual says that the 768k upgrade (i.e., 24 chips on the card) is
>not a good idea "because some applications have trouble dealing with that
>configuration".

Apple's card does not support 768K. That's one reason for the jumpers - you
can enable 512K on the card with one jumper, and the whole megabyte with both.
If you have 768K on the card, you either don't get the last 256K with one
jumper or you get crashes with both since the system will think it has 1 mb
on the card and 256K of it isn't there.
-- 
Randy Shackelford                                 
shack@frii.com