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*Almost* Fastest PowerBook ever, and more to go.

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On 7/21/2018 at 6:25 PM, MOS8_030 said:


I worked at Freescale qualifying the 7448.  (And the 7447, 7450/55, 7410)

Apple kept Freescale on the hook for the 7448 right up to the bitter end, stringing FS along having them believe Apple was going to use the 7448.


At one point I was corresponding via email with an Apple engineer trying to get a firmware update for the P58 mobo's so I could run the Apple test suite and OSX with the 7448.

My email got forwarded to about three other people within Apple because they had already pulled the resources from the team that maintained their PPC test suite.

One of the Apple recipients replied with something like "Why do we need this? We're not using A8 (Apollo 8 ) and hit reply all so I was copied too.


My phone rang literally about 30 seconds after I received the email. It was the Apple engineer I had been corresponding with hastening to explain that I should ignore this particular reply and they were working to get me the firmware update I asked for.

I did get the OF update about three days later and about two weeks later FS got the "official" word that Apple would not be using the 7448. 

(Even though despite Apple's efforts it was apparent to FS long before that Apple wasn't going to use the A8. )


Anyway, I have some photos of the P58 (G4 MDD) test rigs I used at work. I should dig those out. They're hardly proprietary now.



thats some very cool information!


id be very interested in seeing pictures of the whole setup, its interesting how you used MDDs as test beds, im guessing Motorola made up custom CPU cards for the 7448s 360CBGA foot print? (as the stock MDDs use 7455s which are 483 CBGA packages)


im very interested in hearing your stories as I have been doing a lot of work and research into PowerPC CPUs and upgrading various Macs with faster ones :)


which you can read about here 

I also have a few posts on Mac Rumors about my PPC CPU Upgrading adventures :)












I also helped dosdude1 with his iMac G4 upgrade project https://forums.macrumors.com/threads/worlds-fastest-imac-g4-2-ghz-imac-g4-cpu-upgrade.2125765/


BTW do you happen to have any Schematics for Apple desktop machines?


I have quite a few PowerPC Laptop schematics but nothing for Apple desktop machines or CPU cards (the only desktop schematics I have are for iMac G4s and iMac G5s 


I would love to get some as it would help imensly with my research and upgrade projects :)

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Yes, Motorola had their own daughter cards. They used a socket that could accept a BGA part.

I have some photos of the card we used with the P58 motherboards on my other computer, I'm out of town right now.

Here's a photo of two systems I set up to do accelerated life testing with the 7448.

I cranked up the voltage and the temperature and and ran the parts non stop for about three months to induce voltage threshold shifts.



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thats so Awesome to see :)


did you have to run a Custom build of OS X along-side the custom Mobo FW when testing the 7448 CPUs? because AFAIK no version of OS X has native 7448 CPU


(CPU Upgrade companies who sold 7448 upgrades for PMs got around this via either Firmware patches that masked the 7448 as a 7455, or via a special NVRAM patch)


we used the NVRAM patch for when we fitted the 7448 CPU to the 7445 iMac, as the Firmware patch we used to get the machine to POST with the 7448 CPU, only removes the Halt on unknown CPU thing apple has, it does not patch anything else, so to get OS X to boot on the 7448 we had to use the NVRAM patch from one of the CPU upgrade companies.


also out of sheer curiosity and research etc, do you have the Custom Firmware apple provided that let the MDDs Boot with the 7448 CPUs? I would love to play with that :) also reading the Schematics for the DLSD PowerBooks I had theorised that they where going to use 7448s but switched back to 7447Bs at the 11th hour, its pretty cool to see that I was indeed on the right path, but I wonder do you think the DLSD still has 7448 support in Firmware? (I know New world ROM PowerPC macs will Halt on POST if they detect a CPU with an unknown PVR otherwise)


I just wanted to say again how awesome this all is


im quite passionate about PowerPC (Apple) stuff esp the very technical side of things, so this is just beyond awesome and I cant wait to see more :) 


thank you very much for sharing what you have

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  • 5 months later...
On 10/14/2018 at 10:42 PM, MOS8_030 said:

I cranked up the voltage and the temperature and and ran the parts non stop for about three months to induce voltage threshold shifts.


I also joined because of this thread.  Thank you for posting MOS8_030!  How much heat/voltage could the 7448 survive in your tests?  I would like to hear more of these insider details if possible.  Is there any chance of getting some ideas on the firmware changes needed to run the 7448?  That seems to be the main issue with trying to transplant them into powerbooks.

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I guess the only way to settle the matter of what processor is in a given system is a to take a pic. If the processor in said system is a 7448, it will be obvious, and there are enough people that work with static and motion media around here that we could collectively sniff out a fake a mile away.


Edit: Nevermind, saw the most pathetic photochop in the world over in the MR thread. That's the end of that story.

Edited by Paralel
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I like the 12" powerbooks and I've done the possible upgrades.  I took one apart and swapped the chip with a slightly better one and was able to get 1.83GHz that's stable and not too hot.  These chips will usually do 2+ GHz but they take more voltage and put out more heat, so 1.83 seems to be about the limit for the 12" from my experiments.  DFS still works, so that's pretty nice when on the battery.  I'd really like to do this swap with a 7448, but I'm stuck on the firmware.  Can anyone help?







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  • 1 month later...
On 3/31/2019 at 11:19 AM, hoi polloi said:


I also joined because of this thread.  Thank you for posting MOS8_030!  How much heat/voltage could the 7448 survive in your tests?  I would like to hear more of these insider details if possible.  Is there any chance of getting some ideas on the firmware changes needed to run the 7448?  That seems to be the main issue with trying to transplant them into powerbooks.

My memory is hazy but I think the voltage was 1.5v and the temp was 110c.  Apple supplied the firmware patch. I have searched my "archives" and I can't find any copies of the Apple software. In addition to the firmware update we also had a hardware test suite that ran in in OF.

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I'm looking back through some of my old work emails from ~2005 and we were running two Apple test suite tools. One suite was called "iSys" and the other suite was called "INDY". We only ever tested A8 with 10.3 on the MDD G4 systems. I believe the "INDY" software was the old stuff.


Here's an interesting bit I found from that time from an engineer at Sonnet:


"These are two different things as it turns out. The boot ROM does have to change, typically for PVR changes, but also for cache reporting and processor speed reporting - the new PLL multipliers were not part of the old speed tables.

So, one set of changes provides support in the boot ROM. This takes the boot process from initialization, memory configuration, cache configuration, some testing, and then into Open Firmware.

Open Firmware then looks for the official boot device; if OS X is selected, it loads a bootstrap program ("BootX") which does some prep, then reads the kernel image from disk into memory, and jumps to it.

Once the OS X kernel  starts booting, Apple reads the PVR again with a mfspr instruction and then looks up in a processor table all the features and characteristics of the processor. Interestingly, they do not use the information for the boot ROM data structures, but read it straight out of the processor.
Frankly, we may have had some hand in that, as OS X was able to boot on some old, old machines (9500 class) using our processor upgrades that never had the PVR value set correctly in the boot data structures.

So, this is a second set of changes, this time in the OS X kernel - and very minor, as I stated. I don't see any way around it though - Apple reads the pvr, and there is no intervention in the code stream until it is used to look up the processor info in the table.

I routinely have to make custom kernels for new processors (7457, 7447A for example) before Apple provides official support, but we never thought much about it not being part of future OS X versions till the Apple WWDC announcement.

I'm happy to provide any further info on the issue, as we really like the 7448 so far and would very much like to use it in our products when it becomes available."


And here's a note I sent to my boss around the same time.


"We are using a custom kernel now with 10.3.5. That's because the A7PM wasn't out when 10.3 was released. However, I'm sure 10.3.9 supports it.
(Your laptop requires at least 10.3.4 I believe)
To get A8 to work we had to do a firmware update so the system (hardware) would recognize the part. That's a fairly trivial update.
The same custom 10.3.5 kernel works with A8. (I don't know why.)
However, I've tried to boot 10.4.x with A8 and the OS won't load.
I assume because the OS doesn't recognize the PID.
So, yes, in order to run A8 on 10.4.x Apple will have to update the kernel. He's absolutely right that because of this it may be very hard or impossible to make a 7448 upgrade for older Macs.
Of course Apple has always discouraged upgrades anyway, so any support
for 7448 wouldn't be done just for them....
He (and we!) can only hope that Apple will use the 7448. 
It makes it kinda hard for the upgrade companies to move forward.
If you would like more information I can make some discreet inquiries
to the Northern folks. I'd like to get a kernel for A8 and 10.4 anyway."


(I never did get any support for 10.4 to run on the 7448)


I also found some comments about getting the MPC8641D (dual-core 7448) to run on the Mac back then, but that was after extensive hardware/software hax. :)

Edited by MOS8_030
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On 5/28/2019 at 10:40 AM, MOS8_030 said:

I'm looking back through some of my old work emails from ~2005 a

Thank you for taking the time to look back through your files and reply to this thread.  Do you think any of your old contacts would be willing to share the details of these 'minor' changes needed to run a 7448?  I don't think it would be detrimental to their market share at this point.  I know powerlogix/newer technology did come out with 7448 upgrade cards and firmware for the tower macs.  I think these ran with OSX 10.4 and 10.5 (maybe not with 10.3?).  I'm interested in getting a '48 working in a powerbook, which would require some firmware tweaks.  Did you know anyone at Daystar?  I think they had or were working on using 7448 upgrades as well.


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I don't have any contact with anyone any more. What I was hoping to find in my old email was any zip files with the firmware update I used on the MDD G4 systems or any of the updates for OSX but no luck. There's a very slight chance I may have something archived on a CD somewhere. However I think it's probably only my emails I saved from work. (I've already checked the three Macs and one PC I have my files scattered across.)

Anyway, if I do turn up anything relevant I'll post it here.


Motorola had a pretty tempestuous relationship with Apple over the years. Supporting Apple required a massive dedication of resources and as soon as Apple announced the switch to Intel Motorola rapidly disbanded the support group and reallocated the resources and personnel.

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the annoying thing about Apple Open Firmware on the G3 BW and newer is if it does not recognise the CPU thats been installed it will halt on purpose,


older Firmwares like found in the beige Macs, will actually boot on an unknown CPU, obviously all the "extra" bits like L2 L3 cache dont get enabled but at least they boot


thats what the Giga Designs Firmware patch me and Dosdude1 used for the iMac G4 thing does, unlike the more developed firmware patches from sonnet and the like, which will mask a CPUs PVR etc


all the Giga Designs does is remove the "halt on unknown CPU" thing from the firmware, sadly it seems like it the patch only works on Firmware versions 4.7.x and lower (and sadly the Sonnet Firmware patches etc are all machine specific)


so the bare minimum to booting a PowerBook G4 with a 7448 CPU is to figure out how to patch out the "halt on unknown CPU" thing in its Firmware

Edited by LightBulbFun
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