upgrading the ibook clamshell's L2 cache to 1MB

welp, got the new chips in and well... it still isn't passing the mac os 9 built in memory test for cache. starting to think its either address lines or firmware related. dunno if the firmware on here has ever been updated, as a matter of fact. i know for certain these chips are good.
 
well, tested the computer some more and it does work, but disables the L2 cache for whatever reason. maybe lack of address lines or something. gauge pro also doesn't properly see my bus overclock, and assumes the CPU is running at 266MHz with the 66MHz bus even though i had set the bus to run at 100MHz...IMG_20260614_182056.jpg
 
Totally not directly related, but BITD, about a year and a half after I got my DA/733/1M Superdrive model, I started getting the same error you're seeing completely out of the blue in os9, but not in osx... I ASSUME there's some kind of integrity check but i doubt there's any diagnostics for this.

Definitely interested if you can pull this off tough!
 
defor said:
Totally not directly related, but BITD, about a year and a half after I got my DA/733/1M Superdrive model, I started getting the same error you're seeing completely out of the blue in os9, but not in osx... I ASSUME there's some kind of integrity check but i doubt there's any diagnostics for this.

Definitely interested if you can pull this off tough!
Click to expand...
OS X definitely does the checks, and you can check in system profiler if something is amiss or has failed.
 
Oh definitely- I just meant that on that specific machine, i didn't even know it'd failed because OSX doesnt do the popup, and classic wasnt notifying. Anyhow.. definitely gonna be following your attempts if you plan to keep trying!
 
so i managed to get the RAM upgrade to 128MB working, for a total of 640MB on the system. sadly i am still stuck on the cache failing to pass the power on test, which makes the whole machine feel rather slow (powerbook 5300 much?).
 
turns out there is in fact an address line that likely is not connected, A16 on the 128Kx36 chips is on pin 50 although that is a no-connect on the old 64Kx36 chips... probably why the cache isn't working
 
alectrona6400 said:
turns out there is in fact an address line that likely is not connected, A16 on the 128Kx36 chips is on pin 50 although that is a no-connect on the old 64Kx36 chips... probably why the cache isn't working
Click to expand...

Yes, they most likely didn't route all the address lines for the cache.
I know @herd has run their own address lines from under the CPU on a Pismo card before, so it's not impossible to mod the board to add them here:

H

Post in thread 'iMac G3 (Rev A -> C) G4 CPU Upgrade'

The CPU has a bunch of the same L2 power pins, so you'd definitely need to change it somewhere upstream. Based on the pictures above from Daniël, the extra address pin is not routed. However it's not too hard to add it because the pin is on the outside edge of the CPU. I've done this to upgrade a Pismo CPU to 2MB of L2, but the software side of getting it working is a bigger headache.
 
if your upgrading the L2 cache to 1MB total (and not 2MB total) the issue here sounds like Bad soldering or Bad chips, I am quite sure the Clamshell has all the address lines for at least 1MB, and I know @max1zzz has done it it before (but sadly we did not know about the config-block issue at the time) if it is done successfully then the clamshell should boot up without any L2 cache errors and report 512KB of L2 cache until you suitably edit the config-block of the BootROM to enable the full 1MB


2MB of L2 cache is where the address line issues start :) (but as Dan mentioned you might be able to bodge on the extra missing address line)
 
Last edited:
you will have to edit the config block thusly

forums.macrumors.com

[Success] PowerPC Mac Soldered RAM Upgrade

For years now, myself and many others have made attempts to upgrade soldered RAM on PowerPC-based Macs, without any success. As I've found from my vast experience doing such upgrades on Intel machines, just swapping the chips is not all that needs to be done; the system's BootROM also has to be...
forums.macrumors.com forums.macrumors.com

there is GUI tool config block editor, that leaked recently, for editing this sort of stuff, but I have not personally messed with it much other then finding it in the CD and poking at it a bit

archive.org

Apple EVT CD MacOS "Bandit 18 (1.2f4)" : Free Download, Borrow, and Streaming : Internet Archive

This CD was found in an Apple iBook G3 EVT laptop. The disk is labeled Bandit 18 (1.2f4). It appears to contain an installer for MacOS 9.2 along with several...
archive.org

but I think you should be able to use it to edit the config block for the PowerBook2,1 Apple 4.1.7 firmrware update, so it updates that to the 128MB/1MB configuration of your machine

or as Colin does you can dump the BootROM and update things according to the config block document
 
LightBulbFun said:
you will have to edit the config block thusly

forums.macrumors.com

[Success] PowerPC Mac Soldered RAM Upgrade

For years now, myself and many others have made attempts to upgrade soldered RAM on PowerPC-based Macs, without any success. As I've found from my vast experience doing such upgrades on Intel machines, just swapping the chips is not all that needs to be done; the system's BootROM also has to be...
forums.macrumors.com forums.macrumors.com

there is GUI tool config block editor, that leaked recently, for editing this sort of stuff, but I have not personally messed with it much other then finding it in the CD and poking at it a bit

archive.org

Apple EVT CD MacOS "Bandit 18 (1.2f4)" : Free Download, Borrow, and Streaming : Internet Archive

This CD was found in an Apple iBook G3 EVT laptop. The disk is labeled Bandit 18 (1.2f4). It appears to contain an installer for MacOS 9.2 along with several...
archive.org

but I think you should be able to use it to edit the config block for the PowerBook2,1 Apple 4.1.7 firmrware update, so it updates that to the 128MB/1MB configuration of your machine

or as Colin does you can dump the BootROM and update things according to the config block document
Click to expand...
i am going to look into that perhaps, also i wonder if i could change the startup chime to the one from the TAM?
 
tried using the GUI tool but to no avail, the program doesn't recognize my bootrom hardware which is weird. what linux live CD should i use to get the flashrom program?
 

Attachments

  • PXL_20260617_173521681.jpg
    PXL_20260617_173521681.jpg
    1.8 MB · Views: 7
alectrona6400 said:
i was in fact SUCCESSFUL! now i just need to figure out what i need to modify in the bootrom for both the 1MB of L2 cache and 128MB of onboard memory.
View attachment 100277View attachment 100278
Click to expand...
Awesome work so far! I'm eager to try the same modifications to my own iBook. As far as the GUI flashrom program goes, did you make sure to follow this step from Dosdude?
Be aware that to do this, you must ensure the machine is booted into firmware programming mode (hold power button at boot until power LED starts flashing), otherwise the EEPROM will not be exposed to the OS.
Click to expand...

Otherwise, I'm guessing that as long as you pick a Linux distribution that is era-appropriate for the iBook Clamshell, it probably won't matter too much --I'd hunt for an early PowerPC copy of Ubuntu probably. And you're also going to need to find a PowerPC binary of flashrom. Let me know if this makes sense? I can try to tinker with flashrom on my iBook too if you get stuck.
 
You must log in or register to reply here.

Similar threads

M
PowerBook G3 Lombard L2 Cache Problem - Succefuly repaired!
Replies
0
Views
150
mitchW
M
I
PowerBook G4 Titanium (400 MHz) cache chip replacement
Replies
4
Views
2K
obsolete
obsolete
indibil
Imac G3 DV CPU SWAP (just a few steps away)
Replies
15
Views
949
herd
H
W
Power Macintosh 6500 Sonnet G3 L2 Crashes During Boot
Replies
8
Views
2K
willmurray461
W
T
Sonnet L2 Cache Card 300/512k - upgrade cache to 1m?
Replies
1
Views
635
alectrona6400
alectrona6400
Back
Top