The conversation on this page has been archived and is no longer active.

PRAM contents.

Message #1 - Posted 2004/05/03 - Paul Grayson

Is there a definitive list available anywhere that goes into detail as to exactly what is stored in PRAM?

I've just zapped mine and it appears to have resolved a serious performance problem on this iBook, which I suspected was due to the hard drive being accessed using PIO instead of UDMA. To double check this, a detailed list of all the parameters set in PRAM would help.

Message #2 - Posted 2004/05/03 - leeg

Paul Grayson wrote:

Is there a definitive list available anywhere that goes into detail as to exactly what is stored in PRAM?

I've just zapped mine and it appears to have resolved a serious performance problem on this iBook, which I suspected was due to the hard drive being accessed using PIO instead of UDMA. To double check this, a detailed list of all the parameters set in PRAM would help.

A reasonable list of what's in the *NVRAM* may be discovered by the 'print-env' word at the OK prompt. However Apple don't document too much of the PRAM's contents, and indeed tell us not to rely on anything we discover by reverse engineering being available. So *exactly* what is stored in one machine may or may not have anything to do with *exactly* what is stored in another :-/

Graham Lee
I am leeg, for we are many
If it first you don't succeed, I wouldn't recommend giving basejumping a go. http://users.ox.ac.uk/~wadh1342

Message #3 - Posted 2004/05/03 - Paul Grayson

On Mon, 03 May 2004 12:52:05 +0100, leeg wrote:

A reasonable list of what's in the *NVRAM* may be discovered by the 'print-env' word at the OK prompt. However Apple don't document too much of the PRAM's contents, and indeed tell us not to rely on anything we discover by reverse engineering being available. So *exactly* what is stored in one machine may or may not have anything to do with *exactly* what is stored in another :-/

Running 'printenv' from OpenFirmware doesn't offer any real clues.

My problem may have started after playing with a Linux bootable CD distribution, so I'm wondering if that does odd things with the PRAM? I'll have to download the Linux kernel source to find out. That could take some time.

Message #4 - Posted 2004/05/03 - leeg

Paul Grayson wrote:

On Mon, 03 May 2004 12:52:05 +0100, leeg wrote:

A reasonable list of what's in the *NVRAM* may be discovered by the 'print-env' word at the OK prompt. However Apple don't document too much of the PRAM's contents, and indeed tell us not to rely on anything we discover by reverse engineering being available. So *exactly* what is stored in one machine may or may not have anything to do with *exactly* what is stored in another :-/

Running 'printenv' from OpenFirmware doesn't offer any real clues.

No, as I said, this stuff isn't well documented and I don't think that Apple have plans to change that. Indeed even their implementation of OF is severely lacking in help [though there are a couple of technotes, they're bobbins].

My problem may have started after playing with a Linux bootable CD distribution, so I'm wondering if that does odd things with the PRAM? I'll have to download the Linux kernel source to find out. That could take some time.

Ah, is there not a CVSweb interface? There used to be one at lksr.org but it seems to have disappeared :-(.

Graham Lee
I am leeg, for we are many
"Don't rush to implement your commander's orders. Wait until he changes his mind." - Soviet Army saying
http://users.ox.ac.uk/~wadh1342

Message #5 - Posted 2004/05/03 - zoara

Paul Grayson wrote:

Is there a definitive list available anywhere that goes into detail as to exactly what is stored in PRAM?

RATTLE, in most (but not all) cases.

-z-

"I didn't expect the voice of karma to be called Bob." -- Giles, uk.comp.sys.mac

Message #6 - Posted 2004/05/03 - Andrew Collier

Previously, leeg wrote:

A reasonable list of what's in the *NVRAM* may be discovered by the 'print-env' word at the OK prompt.

Typing:

nvram -p

at the terminal is probably more convenient, as you don't need to reboot, and you can copy and paste the interesting bits into google.

Andrew

--- Andrew Collier ---- To reply by email, please use: ---- http://www.intensity.org.uk/ --- 'andrew {at} intensity.org.uk' --
Have you lost your Marbles? http://www.marillion.com/

Message #7 - Posted 2004/05/03 - Paul Grayson

On Mon, 03 May 2004 15:07:18 +0100, leeg wrote:

Ah, is there not a CVSweb interface? There used to be one at lksr.org but it seems to have disappeared :-(.

You can't grep multiple files through such an interface, though.

Anyway I've downloaded 2.6.5 now, but it's going to take a while for me to find anything relevant. I'll probably need to get a version of 2.4 later as that's more likely to be the kernel on that CD.

Message #8 - Posted 2004/05/07 - Paul Grayson

On Mon, 03 May 2004 14:02:32 +0100, Paul Grayson wrote:

My problem may have started after playing with a Linux bootable CD distribution, so I'm wondering if that does odd things with the PRAM? I'll have to download the Linux kernel source to find out. That could take some time.

No, it's not that. They've come back again. They seem to happen after leaving the machine running for a long time, but not sleeping. Then the severe problems return. The only thing I can consider is the hard drive spin down. I'll turn that off, zap the pram yet again, and observe for a few days.

Need Help? Have a Question?

Looking for more help, comments, and answers?

Ask your questions on Ask Different. Ask Different is a community of Apple users ready to help.