>> why does the G5-20" work and the G5-17" 1,9Ghz (x600pro) not?

> Yes, support (unofficial) for the 17" A1144 would be useful.

Seems it's there now:

"Devs/Monitors/Radeon
[...] Added iMac G5 17" iSight compatibility"
https://www.morphos-team.net/releasenotes/3.16

Quote:

Yes and no.

The iMac is one of the few supported options for dual-monitor support so if he sets up Ambient to show up on the external screen before removing the buildin panel he should be good. Until that setting gets lost for one reason or another....

I continue with interesting discussion started ( a liitle offtopic ) here: iMac G5 overclocking

Code:

Fortunatelly, I receive iMac iSight G5 ( A1145 ) and iMac G5 A1058 (which is very probably version overclocked in above links ) schematics.

I can confirm, that resistors responsible for CPU bus clock configuration 3:1 -> 2:1 are:
iMac G5 1.8 GHz A1058: R3012 -> R3028, exactly like mentioned in above links
iMac G5 iSight 2.1 GHz A1145: R4712 -> R4728

Accordind to Northbridge and CPU manuals, the CPU bus clock domain is independent from other clock domains, so CPU speed not change with change of CPU bus speed ( in opposite of G3+G4 overclocking, where CPU frequency derives from bus frequency).

So, all this is theory. In praxis there still can remain risk of damage, because of:
- inappropriate version of real iMac iSight and schematics (not too big risk)
- Northbridge in iMac can have lower "Speed Classification", i.e. maybe in real is not 1.05 GHz capable
- insufficient cooling after bus overclocking
- damage during mounting / dismounting / soldering
- other things I didn't notice



[ Edited by sailor 20.05.2022 - 08:20 ]

> Elastic Interface ( Apple schematics terminology )

In fact, Elastic Interface is a term coined by IBM and adopted by Apple.

> U4 [...] = CP925 [...] = Kodiak

Seems the confusion still prevails:

CPC925 = U3/U3H
CPC945 = U4 = Kodiak

@Andreas
corrected. Too much too similar numbers.

And if I study our iMac G5 iSight Schematics, there is another interesting findings:

iMac use SATA connected HDD and ATA connected DVD.
But in real, used Southbridge have two SATA ports, and only one is connected.
If anybody wants (and he finds appropriate pins on motherboard) I have the scheme how to connect it. It needs four additional condensers, but it is not too complex.

Then you can connect or modern SATA optical drive, or second SATA HDD (with both disks 2.5" size to fit to one 3.5" bay).
Of course, it is only HW point of view. I am not sure if OpenFirmware or OS recognized device which was not taken into account.

Southbridge is Broadcom, type (yet) unknown, but can be ( at least partially ) identified by PCItool, device ID. Apple codename is SHASTA. But for SATA port addition no identification is needed.

I've been using my iMac A1145 for a while now, and for some reason I never noticed, until now, that there doesn't seem to be a brightness option, as far as I can tell, for it in preferences to reduce or increase that feature of the screen itself, or does someone know how to adjust the screen brightness on these iMacs?

There is of course a keyboard control for the PowerBooks, and other notebook type hardware. For the MacMini you need a separate screen that usually has some independant way to adjust the screens brightness but with the iMac there doesn't seem to be this feature supported, as yet, is this an oversight, or a problem in working out just how Apple got it to function with Mac OSX, and make it work within MorphOS?

The API for that exists and I do have a primitive 20% ready screenbar module that uses it.
Maybe I‘ll do the next 75% once I get the new PastePass out of the door.


If I look at what my boss thinks about the use of my time that may end up being in the year 2525……

I’ll be bringing some of the PowerBook services to the iMac support for 3.18…

Quote:

Very cool!

Any idea how hard it is to get a bootscreen going for there?

Just hit a brick wall on trying to update my G5 iMac iSight 20" to 3.17 (currently running 3.16). I'm trying to boot from USB (can't from the optical as it is non-functional), but after the 'quiescence' message I'm getting the following error:

Invalid memory access %SRR0: 00000000.00c02230 %SRR1:100000000.00003030

I've tried re-downloading the iso in case it was a download error, but hit he same problem. Any help would be much appreciated!

Thanks,
Nigel.

Quote:

You're probably booting the wrong boot image. You need use the boot image from the mac_ppc64 directory, not the mac_ppc32 directory.

Ah, user error, might have known! Many thanks, I'll give that a try,

Cheers
Nigel.

Quote:
Indeed, an architecture check at the beginning would be helpful. Maybe at OFW level somehow?

[ Editiert durch polluks 16.08.2022 - 17:48 ]