Author Topic: 1 GB memory to Powerbook G3  (Read 1585 times)

Offline teroyk

  • Platinum Member
  • *****
  • Posts: 623
  • -
1 GB memory to Powerbook G3
« on: July 07, 2020, 11:01:31 AM »
I found ineresting information "you can get to 1 GB of memory using 128 Mb devices as long as they use 4 K refresh rates."
from:
Technical Q&A QA1040,128Mb SDRAM ICs limitation on original "Bronze Keyboard" Powerbook G3
https://developer.apple.com/library/archive/qa/qa2001/qa1040.html

and reading old developer notes for Powerbook G3:
Table 4-6 Sizes of RAM expansion devices and modules (continued)
Device size  Device configuration  Devices per bank  Size of each bank Size of SO-DIMM
64 Mbits      512K x 32 x 4           2                         16 MB                 128 MB
128 Mbits    4M x 8 x 4                8                         128 MB                256 MB
128 Mbits    2M x 16 x 4              4                          64 MB                 256 MB

So does it mean if there is last type with 8 devices per bank or size of each bank is 128 MB, it makes supported 512 MB size of SO-DIMM that is accepted by Powerbook G3?
And of course 512 MB x 2 = 1 GB

Do somebody know any memory brands and models that have those type SO-DIMM memory?

Offline teroyk

  • Platinum Member
  • *****
  • Posts: 623
  • -
Re: 1 GB memory to Powerbook G3
« Reply #1 on: July 07, 2020, 12:09:13 PM »
from one PC site I found information:
"SODIMMS with 32 128Mb chips exist, but they're rare, expensive, and may not fit in the RAM slots with the cover closed."
So it seems that nobody haven't made memory chips that looks like many 128Mbit chips to outside.

Powerbook G3 Firewire and Pismo doesn't have this problem.

EDIT: was typo in Pismo.
« Last Edit: July 07, 2020, 12:39:08 PM by teroyk »