Hi,

I have 2 almost identical PowerMacs G4 MDD - one is 2x867MHz (133MHz bus), other is 2x1.25GHz (166MHz bus). I'm exchanging gfx card (Radeon 9000 MAC edition) and hard disk between them.

Problem is - the 1.25 one works OK, but 867 doesn't boot, I have to boot with alt pressed and click "next" (MorphOS is the only OS on this disk). When I do it - MorphOS works OK, when I don't - I have white screen, but I can reboot through ctrl-amiga-amiga.

Where could be the problem?

are your jumpers on your drives set to master/slave instead of cable select ?

No, it was CS on HD. I've changed it to Master (it's single drive), no results.

Perhaps the default boot parameter in openfirmware is not good enough? It might have being modified for MacOS, and it tries to boot somewhere else... although the fact that crtl+amiga+amiga reboots probably invalidates this option...

The part about that it boots while pressing alt and selecting morphos, makes me think about something with openfirmware boot parameters...

Someone told me to reset openfirmware (via reset-nvram and reset-all in OF), I've done it with no result.

According to my info, the dual 867 is

PowerMac3,6 (MPC7450): dual 867 MHz (internal L2 256KB, external L3 2MB)

There is a known problem with MPC7450 CPUs if the console is active (which it is for Radeon9000)
It will be fixed for next update.

Where did you get that info? According to my knowledge - all MDD have 7455, and MorphOS says the same.

> According to my info, the dual 867 is PowerMac3,6 (MPC7450)

"Processor Type: PowerPC 7455 (G4) x2"
http://www.everymac.com/systems/apple/powermac_g4/stats/powermac_g4_867_dp_mdd.html

What's your source?

Ok, guess I need to update my info then.

So what is madman's problem then ?

What happens if you swap the cpumodules ?

I'll try tomorrow... I think it's not a problem, but maybe?

Well depending on what happens you can rule out the cpuboard ( or not )

I've decided to leave CPUs as they are to avoid further problems. I assume that the connection Radeon-MDD867 is in some way bad, I'll test it with other card and maybe report.

did you try to reset the motherboard with that little button next to the clock battery?

I had some problems today with reinstalling MorhpOS, it always hanged during installation. I burned the ISO on three different CDRs, swapped hardrives and dvdrom ... nothing helped untill I pushed that button. I am not sure what was wrong and I also do not know what it did besides resetting Openfirmware... but it helped.