OpenFirmware for iMac G4

[Mainframeguy]

This thread and its predecessor have been the most helpful I ever had on OSNN (is this a Mac thing?! :dead:?) BUT the iMac remains dead. I am thinking of pressing on with SoDimm upgrade if they spring £50 to fund - but I am concerned lest the same boot disc issues hit me for OSX suppose the firmware does not allow that either?

Anyone offer any open firmware guidance on that? Things get eerily technical there, I have seen I could draw on my assembler knowledge and write Forth scripts and so on, which I would prefer not to get distracted by (plus I seriously do not want to "brick" the iMac!). I may make separate thread of this (nto sure mods can do that with a post though?! :yowch

 

[X-Istence]

Here is a list of the commands that are available in OpenFirmware: http://www.firmworks.com/QuickRef.html

And here is some people trying to troubleshoot a G3 which may help you as well:

http://discussions.apple.com/thread.jspa?threadID=1526136&tstart=0

 

[Mainframeguy]

The first I had googled myself - but ta (it just led me on a trip down memory lane with FORTH and Assembler - did not help though!

The second link may be useful - we shall see...

I am also trying for the Sodimm upgrade which would mean OSX (did I say that?!)

 

[Geffy]

If its a G4 and you want the X on it I'd probably try Panther instead of Leopard or Tiger, though Tiger ran pretty well on my iBook G4.

 

[Mainframeguy]

Thanks Geffy - the latest bad news is it does not take Sodimm - it needs the other ancient one (ASDimm?) which I can only get in 256 or maybe 512 at a pinch - this is looking like a tough save!

 

[X-Istence]

It needs a standard SODIMM, so that should not be an issue at all. You may be looking at the wrong memory, I believe in the iMac G4's, like in the G3's the RAM for the graphics card is separate.

Do you have any more information on this iMac G4? There were several models made, any more info would be helpful (processor speed, screen size, board revision).

 

[SpiceWare]

Check here to figure out the right kind of memory.

 

[Mainframeguy]

Thanks spice - I already had the base plat off - so I know it needs 184 pin SODIMM - which amazes me because you link shows the 200's!

I am confused - but I bought a 200 pin sodimm and as son as I offer it up to the slots you can see the gap is misplaced - what is even odder is if I look here then it seems Apple tell you to get regular sodimm! But it does not fit in this one! Also the top of that screen seems to have a pic of a 184 pin stick! Yet all the memories offered are 200 - I am left confused by online - but the reality of the slot cannot be denied! Anyway - memory is only a means to attempt OSX - until then what can I do to get ANYTHING AT ALL to run from the CD or a USB stick in order to do anything much?

 

[Mainframeguy]

OOOoops sorry X I added the more info to another thread... I'll copy it here

I think it is this model with 15" screen - having removed baseplate I can confirm there is a spare airport slot and indeed one for some 184 pin sodimm - it has a single stick of ram I can see in more conventional holder inside after I take the torx 15 to it - but I only want to go there again if I need to change the CD drive. Nothing seems to read from the drive to boot - but the drive does whir into life and seems recognised in all other ways.

I cannot imagine the sodimm goes any where else and the standard stick I bought (and returned - did not seem to fit no way no how. Anyway - memory is NOT going to resolve my problems without a boot from other than HD device!