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Rikintosh

macrumors regular
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Apr 22, 2020
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São Paulo, Brazil
I was looking for schematics for my ibook 1.33 when I happened to open a schematic of what appeared to me to be a PBG4, but in the processor section, it is designated as 7448 (and not 7447b as it should be), it seems that apple really intended to release a PB G4 7448 that some people say never saw the light of day, while others claim that at the end of production apple used the 7448.

Well, I don't want to create a discussion if Apple ever used the 7448, I just want to show that there is a schematic showing it.
 

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DearthnVader

macrumors 68000
Dec 17, 2015
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It they ever used a 7448 it was never an official product just an R&D Mac.

Others have found that later PPC did include support for the 7448 so it's not surprising you found this in the docs. Later PPC don't need the bootrom patched to support the 7448, so Apple certainly planed on using it, but moved on to Intel instead and no such Macs where ever released.

The rare thing would be to find on of the R&D Powerbook G5's or even a schematic for that!
 

LightBulbFun

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Nov 17, 2013
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It they ever used a 7448 it was never an official product just an R&D Mac.

Others have found that later PPC did include support for the 7448 so it's not surprising you found this in the docs. Later PPC don't need the bootrom patched to support the 7448, so Apple certainly planed on using it, but moved on to Intel instead and no such Macs where ever released.

The rare thing would be to find on of the R&D Powerbook G5's or even a schematic for that!
somewhere I do have schematics for a "PowerBook G5"

or certainly an Portable with G5 and U3Lite and portable/battery power management, what the actual prototype looked like is anyones guess LOL

yeah here we go, theres a board view file in there, not sure I ever actually opened it (at the time board view software was a bit in its infancy and the older board view files took quite bit of faffing around to open) if someone can get said board view file open the shape of the logic board might give us some clues!




as you say with the DLSD above its no secret that apple was certainly planning on/playing with the 7448, but they just never went through with it, me and a few other members on here talk about in some old threads as there used to be an annoying persistent rumour that DLSD's had 7448's which they did not!

example where I talk about it as far back as 2017! https://forums.macrumors.com/thread...de.2065752/page-3?post=25045724#post-25045724
 

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Rikintosh

macrumors regular
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Apr 22, 2020
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São Paulo, Brazil
I also read somewhere that Apple tried to throttle the latest PB G4's so the newer intel c2d's wouldn't be humiliated.

Despite the thermal problems (I'll explain later) both the 7447b and the 7448 can reach higher clocks, apparently a 7448 running at 2.3ghz could unseat the first core2duo, especially if there was an L3.

I know that there was a physical prototype PB dual g4, it seems that apple had no intention of using a G5 9xx, but not because of thermal problems, but because this model was never built to take advantage of energy consumption, so probably, apple would launch a dual PB G4, with maybe a radeon x1600, and then in the next generation it would go to Power6.

The thermal problems on ALL Apple PPC machines (except the G5) basically exist because Apple is an ******* and prefers its products to bake in hellish heat than make a little noise with a fan running. They also always used bad fans, poorly dimensioned cooling system, and low quality. The TDP of these processors is extremely low, they heat up because of a poorly designed system. I myself made a post some time ago, explaining how it is possible to incredibly lower the temperature of a powerbook, using some sandpaper, and cutting holes for the fan to suck the air. In addition, the precarious cooling system throws a lot of heat against the LCD, causing the diffusers to warp, and this results in a "shadow" on the screen of notebooks after a few years of use.

The acrylic box where the current prototype of the G4 dual is, had stickers designating Q51 (codename of the PBG5), this means that apple probably built the prototype motherboard of the PBG5 at some point.
 
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DearthnVader

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Dec 17, 2015
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Red Springs, NC
I also read somewhere that Apple tried to throttle the latest PB G4's so the newer intel c2d's wouldn't be humiliated.

Despite the thermal problems (I'll explain later) both the 7447b and the 7448 can reach higher clocks, apparently a 7448 running at 2.3ghz could unseat the first core2duo, especially if there was an L3.

I know that there was a physical prototype PB dual g4, it seems that apple had no intention of using a G5 9xx, but not because of thermal problems, but because this model was never built to take advantage of energy consumption, so probably, apple would launch a dual PB G4, with maybe a radeon x1600, and then in the next generation it would go to Power6.

The thermal problems on ALL Apple PPC machines (except the G5) basically exist because Apple is an ******* and prefers its products to bake in hellish heat than make a little noise with a fan running. They also always used bad fans, poorly dimensioned cooling system, and low quality. The TDP of these processors is extremely low, they heat up because of a poorly designed system. I myself made a post some time ago, explaining how it is possible to incredibly lower the temperature of a powerbook, using some sandpaper, and cutting holes for the fan to suck the air. In addition, the precarious cooling system throws a lot of heat against the LCD, causing the diffusers to warp, and this results in a "shadow" on the screen of notebooks after a few years of use.

The acrylic box where the current prototype of the G4 dual is, had stickers designating Q51 (codename of the PBG5), this means that apple probably built the prototype motherboard of the PBG5 at some point.
The 7448 doesn't support L3 and the main thing holding back the G4 systems was the lack of true DDR support.

CoreDuo wasn't greatly faster than the 7448, but it was dual core and supported true DDR bus and RAM as well as double the L2 cache.

Moto didn't care about Mac's, they cared about imbedded systems and it really wasn't till much later ( Freescale/NPX )That a real chip that could have competed with the Core/Core2 was designed.

It was too late, Apple's bread and butter was laptops and they could not wait. The G5 chipset was too power hungry for a laptop.

By the time they clocked everything down on the G5 laptop to keep it from setting your papers on fire, it was slower than the 7448.

It wasn't Apple, it was IBM and Moto!

But that's all over now, and Apple has everything pretty much in-house now but the Fab.

So if there is any switch back to an external design we can blame that direct on Apple.

Overall the switch to Intel was great for Apple, but the desktop towers would have been better on Power for quite some time. It was just a matter that IBM only cared about CELL.

Pro Towers really don't rake in the cash like laptops do.

Not that any of it matters now, Apple is a Cell Phone company that makes some other ****.
 

Rikintosh

macrumors regular
Original poster
Apr 22, 2020
204
242
São Paulo, Brazil
Yeah, I liked Apple until they released the first macbooks with a glass screen. From then on (that time) they began to treat the consumer like garbage, pushing products with intentionally flawed design, and almost impossible to repair. These days, an iphone has become virtually irreparable even for a professional with the necessary machinery.

I like powerpc's a lot, I intend to build a powerbook g5 from an imac g5 in the distant future. Currently I'm just trying to put together dream builds with as much as possible (aka iBook 1.6ghz)

In the past I've had a 17 inch Powerbook that has been upgraded to 1.9ghz. It performed well in games, but it was still bad for internet (powerpc doesn't really like web 2.0), virtualpc was also slow, I believe my imac g5 1.8ghz was faster.
 
I was looking for schematics for my ibook 1.33 when I happened to open a schematic of what appeared to me to be a PBG4, but in the processor section, it is designated as 7448 (and not 7447b as it should be), it seems that apple really intended to release a PB G4 7448 that some people say never saw the light of day, while others claim that at the end of production apple used the 7448.

Well, I don't want to create a discussion if Apple ever used the 7448, I just want to show that there is a schematic showing it.

This was discussed here in 2019, with a citation (the last link in that post) to 68kMLA’s forums on what happened.

The final G4 boards designed for, at least, the upper two PowerBook G4s (revised to use PC2 RAM) expected an inclusion of the 7448 chip, but things changed abruptly during development (July 2005, I seem to recall, was when these decisions occurred). To wit, there are components labelled within the A1138 and A1139 PowerBooks which specify “PowerBook G4 1.67 GHz or higher” — meaning, Apple’s designers of the revised logic board were working to accommodate a faster CPU, such as what was expected from the start of 7448 production, but the executive decision to halt those plans fairly late in the production cycle is what thwarted that from ever happening.

Even so, as the specs of the new logic boards could accommodate the 7448 processor, Daystar and others provided that as an upgrade service. They likely relied on info within the schematics you referred to.

I also read somewhere that Apple tried to throttle the latest PB G4's so the newer intel c2d's wouldn't be humiliated.

“I read/heard somewhere” is not a reliable citation for, well, anything, anywhere, ever — especially not in this (dis)information age. :)
 

GMShadow

macrumors 68000
Jun 8, 2021
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7,496
To wit, there are components labelled within the A1138 and A1139 PowerBooks which specify “PowerBook G4 1.67 GHz or higher” — meaning, Apple’s designers of the revised logic board were working to accommodate a faster CPU, such as what was expected from the start of 7448 production, but the executive decision to halt those plans fairly late in the production cycle is what thwarted that from ever happening.

Given how fast the Intel switch actually happened (compared to Jobs's initial announcement of 2 years) I would hazard a guess that at least *some* of the reason was simply "We're going to have a 15" Intel-powered 'Book shipping by February 2006, don't bother investing more engineering time on what will soon be a dead-end product."

Granted, some of the decision making at the time was odd - the iBooks ended up with a higher RAM ceiling than the 12" PBG4, the 'silent upgrade' Mac mini models, the shipping of the iSight iMac G5s (which had a major casing redesign compared to the prior one, though I think they reused a lot of that for the Intel successor) for all of three months. Granted, on that last one I think Apple may have felt it important to keep the iMac more up to date for some reason.
 

Needleroozer

macrumors regular
Mar 29, 2013
137
197
somewhere I do have schematics for a "PowerBook G5"

or certainly an Portable with G5 and U3Lite and portable/battery power management, what the actual prototype looked like is anyones guess LOL

yeah here we go, theres a board view file in there, not sure I ever actually opened it (at the time board view software was a bit in its infancy and the older board view files took quite bit of faffing around to open) if someone can get said board view file open the shape of the logic board might give us some clues!




as you say with the DLSD above its no secret that apple was certainly planning on/playing with the 7448, but they just never went through with it, me and a few other members on here talk about in some old threads as there used to be an annoying persistent rumour that DLSD's had 7448's which they did not!

example where I talk about it as far back as 2017! https://forums.macrumors.com/thread...de.2065752/page-3?post=25045724#post-25045724
Absolutely fascinating!

Block diagram from the schematics:
1678759401999.png


I was able to open PBG5.bvr without any problems using OpenBoardView.

Top of board:
1678758914554.png


Bottom of board (annotations added):
1678759318383.png


J4010 and J4020 are DDR SODIMM slots (333MHz, 128bit, 2.5V).
J9020 - Firewire 1934B connector (Firewire 800)
J9010 - Firewire 1394A connector (Firewire 400)
J8710 - Gigabit Ethernet (J8700 in the block diagram appears to be a typo)
J5690 - S-Video connector
J5900 - DVI-I connector

U2300 - "Shasta" chipset/Southbrdige
U5700 - SIL1178 TMDS encoder (used for DVI output)
U8600 - "Vesta" Ethernet/Firewire interface
U2900 - PPC970 "NEO 10S" CPU
U3 - Northbridge "U3Lite"
U4900 - ATI M11 AGP-connected GPU - might be an "ATI Mobility Radeon 9700"

There are connectors running off the logic board for left and right USB 2.0 ports, an audio codec, ATA ports for both hard drive and optical drive, PCI for the AirPort card, and a Cardbus connector. Interestingly, the trackpad is annotated as being connected via USB and handling the keyboard signals as well, like on the early Intel MacBook Pros (older PowerBooks used ADB for those interfaces).

There are two fan connectors, and the display is connected via LVDS rather than TMDS.

It seems like this was going to fit roughly into the footprint of a PowerBook G4 based off the external connectors. I would love to see what the heatsink solution for this beast would have looked like...
 
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