taken from Apple technical Q&A QA1040 apple seems to destroy data for some reason ?
making sure this info doesn’t dissappear :

>128Mb SDRAM ICs limitation on original “Bronze Keyboard” Powerbook G3
>
>
>Q: Using 8×256 Mbit devices (ICs) to create 256 Mbyte SO-DIMMs doesn’t
>work properly on the pre-Firewire, “Bronze Keyboard” Powerbook G3.
>
>Why do these ICs not work properly?
>
>A: The “Grackle” memory controller, used in the original (pre-Firewire)
>”Bronze Keyboard” and the previous Powerbook G3s, does not support 256 Mb
>devices as it lacks the extra “column” address to go higher than 128 Mb.
>These limits are implied in the RAM Expansion section, Table 4-6
>(http://developer.apple.com/techpubs/hardware/Developer_Notes/Macintosh_CPUs-G3/PowerBookG3Series_1999/101_.57.html#pgfld=5578) of the PowerbookG3 developer note.
>
>However, you can get to 1 GB of memory using 128 Mb devices as long as
>they use 4 K refresh rates.
>
>Powerbooks using the “Uni-N” memory controller, as in the (Firewire)
>”Bronze Keyboard” Powerbook G3 and the current Titanium Powerbook G4, have
>no 128 Mb device restriction.
>