Backlight control on the 12" iBook G4 A1054 1.2GHz late 2004

[LarsG5]

Hi,
I have a 12" late 2004 iBook G4 (@1.2GHz) and well, I have managed to resolve most of the issues of running OS9 on it.
Of course I'm not counting the obvious unfixables, like a lack of sleep option or Airport/USB 2.0 support - these are obviously a no go.

BUT I am still looking for a solution to:
1. iBook running really really hot under OS9. It runs much cooler on OS X, so I suppose it's a software/OF (?) related issue.
2. As the topic of this thread suggest, I cannot make the backlight control to work. I have used this ROM file (2018-05-05 darthnVader ibook backlight 0x1c30 ::r3.hqx) to make the screen at least usable, but it's stuck at the highest level of brightness. Still better than every other solution I have found so far, but yeah, after several minutes of using the iBook my eyes start to sore.

So my question is: Has any of you found any solution to these issues?

Thanks in advance

[darthnVader]

I found with some iBooks, that the backlight keys get inverted, try using the up backlight key to lower brightness.

Does the brightness control show in the Display Control Panel?

Also, as far as the system running hot, it should be cooler under OS 9, unless you hack about in OF to set dfs_high, as but default, OS 9 runs the CPU @600Mhz.

[LarsG5]

Hi, thanks for your answer.

Initially I had this problem with iBook booting with its screen completely dimmed out and inverted backlight control keys, but then I used your custom rom posted in another thread that made the display be constantly at its fullest brightness level with no way of dimming it (neither keys nor control panel do anything). I still prefer it to be this way, since the original rom makes the screen too dimm even at its brightest setting. So yeah, I'm looking for a "mid-way" sollution

Second issue: even when my iBook was downclocked it still run hotter under OS9 than OSX. Thus my question, since that's a somewhat concerning.

Btw, thanks for everything you do here. You've helped many of us enjoy OS9 to its fullest.

[LarsG5]

Regarding overheating issue:

I dont know who that guy is, but I totally owe him a good pint of beer!
(http://mac-classic .com/posts/2020/01/13/controlling-system-fans-with-open-firmware/) (remove the space bar)

Long story short: he found a way of controling the fan speeds via Open Firmware. Setting it up with a script method he explains at the end makes it so you can easily just change the speed value using Simple Text and then reboot your machine. That's probably as best as it gets until somebody finds out the way of implementing full cpu power management.

Until that, the lack of backlight controls is the only issue left for me. Any help much appreciated.