No, but I will try that. I have a hard time now working on my house so sorry for not posting anything in a while.
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Well... I screwed up my PBG4 DLSD
- Thread starter JoyBed
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Hey Joybed ! Hope you are doing well, man.. Its been awhile. So, how is the 4GB G4 project going ? Let me know if you get it.
Weeeell.. Oukay, after studying the 860 pages about the PPC 74XX series of CPUs and achematics of the DLSD I figured out that nothing makes sense. The 74XX series are capable of addressing 4 Petabytes of virtual memory and 64Gigabytes of physical memory. The 74XX CPUs have 32 and 36 bit addressing modes and the northbridge have 32 bit addressing. The northbridge is wired to the ram slots thru 32 bit addressing lines so the maximum is 4Gigabytes. So the hardware can handle 4Gigs. So checkmark on that. The OS X is capable of more than 4Gigs as the G5 machines have more than 4Gigs so checkmark on that. The last component is the OpenFirmware, it can see the modules but it by default allocates just 2gigs max. You can modify the addressing tables to more than 2gigs. I have an idea but that needs to get the PSU in my MDD working again.
Yes, the hardware supports 4GB, but Apple is the one responsible for crippling the potential of the G4. Call it corporate greed and money.. the G4 was underpowered because Apple did not allow it to accept 4GB at the time. I would like a G4 with 4GB of memory and it can be done based on your research - the memory controller needs to be re-written to accept the higher amount and also Open Firmware. If you can modify the Addressing tables to allow 4GB, then that would be cool.
Quick update: I found out what file exactly is against the ram size above 2Gigs and maybe(just maybe!!) I can replace it with the one that will accept more than 2Gigs.
Ok, theoretically speaking, could I then be able to upgrade the G4 Titanium's memory to 2GB or 4GB or is this for the PowerMacs only ? Certainly, I'd like to get 2GB or more out of the G4 Titanium 1ghz. Yes, I am using this and compared to the G4 DLSD 1.67 I feel this thing is more responsive , probably due to the 1MB L3 Cache. 7447a/b lack L3 cache, but have a larger L2 cache of 512mb.
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U me both.
I dont have the schematics of the TiBook so I cant say what is the hardware limit of that specific machine, And its not just for the PowerMac because I started exprimenting on my DLSD, my MDD was brought back to life just yeasterday and also I dont have schematics for that either, so the testing for more ram isdoable just on my DLSD. If I can get the OS X to boot with the more ram than I will move the HDD to the MDD and start trying what amount of ram it will accept. Evetualy I will release the files if they will work.
Meanwhile, I can try to find the schematics for the TI G4 1GHZ.. It would be nice to have 4GB memory in this thing.
Okay, when you find them I will tell you exactly how much ram it can handle by hardware design. But also imagine not just 4gigs but also a 7457 clocked at 1,5ghz in it with a 4mb L3 cache.
Actually, the Titanium G4 1GHZ I have has the same processor as the MDD I believe - a G4 7455. Onyx lists it as Apollo with its codename. I will have to search old developer sites to find it. Is there a way to even increase the L3 cache ? 1MB is nice, but 4MB would be sweet.
Yeah I know, but thats the 7455, but it would be cooler with a 7457. The MDD has 2MB L3 for each cpu. But the 7457 can support up to 4MB.
As I said, I will try to find it. Btw, when you are using your PPC macs, do you have JAVASCRIPT disabled ? I find webkit runs a lot faster and I can type what I see where as with Javascript enabled macrumors is so slow and typing I have to wait for a 2nd or two for a letter to appear. Kinda like ghost typing.
Hi Joybed ! I think I found it. This site gives the whole thing about the MPC7455 G4 which is the processor inside the Titanium G4 1GHZ and other models, including the MDD G4.
MPC7455 Datasheet - Free PDF Download
Download the MPC7455 datasheet for detailed specifications and information on the MPC7455 electronic component.
Let me know what you think and if its possible to go to 4GB PC133 memory on the G4 Titanium.
Hi Joybed ! I think I found it. This site gives the whole thing about the MPC7455 G4 which is the processor inside the Titanium G4 1GHZ and other models, including the MDD G4.
MPC7455 Datasheet - Free PDF Download
Download the MPC7455 datasheet for detailed specifications and information on the MPC7455 electronic component.datasheetspdf.com
Let me know what you think and if its possible to go to 4GB PC133 memory on the G4 Titanium.
I haven't seen any 1GB or 2GB PC133 SO-DIMMs in the wild...
It would be nice if the L3 can go higher than 1MB, maybe to 2MB ?
Wait I didnt meant the datasheet of the CPU, I have all the datasheets a documentfor the whole 74XX series. I need the schematic diagrams of the TiBook itself.Hi Joybed ! I think I found it. This site gives the whole thing about the MPC7455 G4 which is the processor inside the Titanium G4 1GHZ and other models, including the MDD G4.
MPC7455 Datasheet - Free PDF Download
Download the MPC7455 datasheet for detailed specifications and information on the MPC7455 electronic component.
Let me know what you think and if its possible to go to 4GB PC133 memory on the G4 Titanium.
Oh, you mean the service guide - the pull apart guide ? I think I have that too. I can upload it here when I find it.
I found that too but there are no board schematics in that. I need the wiring diagrams for the motherboard. How things are connected to each other.
Not sure you're going to find one in the wild. Usually the service guide was as good as it got. If anything needed more detailed repairs, Apple would just ship out a new logic board to the service centre. I doubt they ever got the soldering iron out or did any more intensive diagnostic work than the software tools Apple supplied to them but it doesn't hurt to search.
Ok, I found the developer site for the 1Ghz titanium G4
Because I have the schematics of my DLSD and the iMac G5 but I cant find them for thr TiBook.
IDK there was a site with like 30 schematics of 30 devices from PPC and two or three of the early Intel.