Changing the Open Firmware screen resolution?
jimrh at charter.net
Sun Feb 5 14:33:59 EST 2012
From: Jackoverfull [mailto:jackoverfull at gmail.com]
Sent: Saturday, February 04, 2012 7:14 AM
To: Jim Harris
Cc: yaboot-users at lists.ozlabs.org
Subject: Re: Enable multiple OSX boot option and intellegent labels?
Il giorno 04/feb/2012, alle ore 06.50, Jim Harris ha scritto:
What you wrote was VERY odd, so I must did a few tests on my iMac G3, the results were rather surprising. My compliments: you just led to the discovery of a "new" Tiger bug (or "feature", perhaps).
If I set the resolution on my 10.4.11 system to 640x480 it comes back to the one that was setted previously (1024x768 or 800x600) on logout (shutdown/reboot included), hence setting the open firmware resolution to that one as well. On Mac OS 9 everything works as expected and if I shut down the system with a resolution of 640x480 it boots with an open firmware with big text.
I think, after a few minutes of reflection, this is actually not a bug, but a perverse feature of OS X: actually if you change the resolution to 640x480 from the Preference Pane (not from the menu) you are warned that some software may appear incorrectly (basically because many applications assume a minimum screen estate of 800x600 or even 1024x768). It is possible that someone in apple chose to restore the previously used resolution on a 640x480 logout thinking that noone would ever willingly use a resolution so low.
Anyway, 800x600 could still be a viable choice, see if it fits your needs.
Also, the ASCII art thing wasn't (solely) a joke: it could be a viable way.
I am trying to deliberately send all messages to this group in plain-text, so that there are no mistakes.
Re: Bug (feature!) in Tiger.
This is not a *Tiger* issue.
What I want to do is to set the screen resolution while within *OPEN FIRMWARE* so that the screen is easier to read.
What I am doing is this:
1. Perform the Macintosh "four-finger-salute". . . OPT - CMD - O - F . . . . to get into the Open Firmware editor.
(This is a very bad pun on Microsoft's "three-finger-salute" CTL - ALT - DEL)
2. Notice that the size of the displayed characters on the screen is very small.
3. Execute a "printenv" command to print the entire list of environment variables.
4. Notice that "screen-#columns" is set to "100"
5. Notice that "screen-#rows" is set to 40
6. Set "setenv screen-#columns 50" and "setenv screen-#rows 20" (essentially dividing both numbers in half)
7. Re-run the "printenv" and note that the values entered have "taken" also note that the screen-resolution has not changed.
8. Execute "shut-down" to write novram and power down the computer.
9. Restart as in #1 above.
10. Note two things:
a. The screen resolution within Open Firmware has not changed.
b. Executing a "printenv" shows that the values entered are still there.
I have not figured out a way to make the OPEN FIRMWARE screen text larger.
p.s. Ascii art would be both time-consuming and complicated to implement - especially within the confines of the ofboot.b file - to the point where it would be cheaper and easier to just go buy a monitor that is 2 x 1.125 meters in size! (laughing)
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