Re: hosed nvram on OldWorld Mac
Dang, this arrived with perfect timing! Get it, timing? See my [lengthy] next post for details. I'm still composing it.
Michel Lanners wrote:
> On 3 Feb, this message from Andrew Sharp echoed through cyberspace:
> > No, I'm getting no output on the monitor.
> Important side-note: control video hardware as initialized by OF is
> notoriously bad at doing monitor timings. By default (i.e. after a PRAM
> reset) it sets up some weird mode that resembles 640x480@60HZ, but
> Depending on your monitor, it may or may not sync to this sh... My old
> Phlips 17B does, my newer Dell P990 doesn't.
> If that is your problem, get yourself a serial console, reset PRAM, and
> boot with cmd-opt-O-F into OF, set your terminal to 38400 and conectit
> with a null-modem cable to the modem port. You should have the OF user
> interface there.
> >From there, do like this (from a mail from some time ago...):
> Fixes for Apple OpenFirmware 1.0.5
> Alan Mimms (firstname.lastname@example.org)
> Sun, 17 Aug 1997 19:08:19 +0000
> I have finally had enough with the buggy screen and disk drivers in Apple's
> Open Firmware on PowerMac 7200, 7500, 7600, 8500, 9500, and probably some
> others I'm forgetting. So I have written some NVRAMRC based patches to
> Open Firmware to hack around the bugs enough for my purposes anyway. I
> hope the hacks may help you too.
> Start up and break into your Open Firmware -- Cmd-Opt-O-F during the boot
> beep held down until the "user interface" for Open Firmware comes up on
> your screen or, if you're smart, your serial port. The banner printed by
> Open Firmware shows the Open Firmware version. These patches ONLY apply to
> Open Firmware version 1.0.5. Other versions will crash if these patches
> can be applied at all!
> Type at the prompt:
> and hit control-L to see the cryptic stuff that is part of your Open
> Firmware's startup sequence. This stuff patches various bugs in the ROM.
> Hit control-N enough times that you no longer see a new line of
> gobbledegook every time several times in a row. This means you're at the
> bottom. Either paste the following into a terminal session (NOTE: must be
> at least a dozen or so ms delay between characters and maybe 100ms between
> lines to work right!) or else enter the following lines very very carefully:
> dev /bandit/gc/via-cuda
> ' write value &W
> : -&We &W swap - execute ;
> : P1 4D8 -&We false 548 -&We ;
> &W FC + ' P1 BLpatch
> : P2 0C 2 ms ;
> &W E0 + ' P2 BLpatch device-end
> : wBoot
> boot-device ['] $boot catch drop
> ." -Waiting for boot-device" cr
> d# 500 ms
> key? until
> Note that ALL whitespace above except for the line indentation is REQUIRED.
> FORTH is a very very very strange "language". It may be safe to leave the
> line indentation as I have it above when pasting if you wish. It's
> wasteful but who cares?
> At the end of this laborious typing (or pasting) session hit control-C (yes
> that's right: control-C is the end of editing session character in Open
> Firmware). Then type at the prompt
> to save the changed NVRAMRC variable into NVRAM.
> The first block fixes a bug in the via-cuda driver in which not enough time
> is given for the device to settle when it is told to set the video
> controller's clocks up.
> The second block defines a FORTH word that can be used in place of the
> normal boot-command contents to wait for the disk to spin up before
> attempting to really boot. This avoids the standard "black screen the
> first time you power on the computer each day" problem.
> Then type at the prompt
> setenv boot-command wBoot
> This sets up the default command executed on auto-boot (normally on power
> on) to run the above disk spinup waiting hack.
> FYI: the reason I know about this stuff is that I worked for about two
> years as the Copland booting guy. Sheesh...
> Please don't inundate me with a bazillion questions about Open Firmware. I
> have a real job and it takes 60+ hours a week of my time. I get PAID to do
> it. I just did this to fix MY PPC Linux box and I wanted to help you folks
> out a teeny bit if I could. No, I don't work at Apple anymore. Cancelling
> Copland was the last straw. I worked there more than nine years. (sigh)
> Happy trails.
> A copy of the universe is not what is required of art; one of the damned
> things is ample. -- Rebecca West, The Creators, by Daniel J. Boorstin
> Hope this helps
> Michel Lanners | " Read Philosophy. Study Art.
> 23, Rue Paul Henkes | Ask Questions. Make Mistakes.
> L-1710 Luxembourg |
> email email@example.com |
> http://www.cpu.lu/~mlan | Learn Always. "