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.htmland 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?