Mac OS 9 Lives

Classic Mac OS Hardware => General Hardware Discussions => Topic started by: bamdad on September 17, 2021, 06:23:33 PM

Title: pismo firmware downgrade
Post by: bamdad on September 17, 2021, 06:23:33 PM
hi everyone,

a while ago when i was still using an IDE2SD adapter in my pismo i was having all sorts of sleep problems. after switching to an SSD it turned out to be the fault of the adapter, but in the process of debugging i had clumsily updated the firmware to 4.1.8..

this rendered the brightness control keys nonfunctional in OS 9.0.2.. which is annoying as hell because this is my go to backwards-compatible machine. they work fine in OS 9.1< and OS X but it sucks to have to do reboots just for this.

so.. there is a documented record of a downgrade of a MDD G4 here: http://mac-classic.com/articles/downgrading-a-powermac-g4-mdd-firmware/

it seems i only need a firmware file. too bad these seem to be - according to the aforementioned description - some sort of executable files so even if someone has a non-upgraded pismo and would dump the OF contents for me, i would likely not be able to run it, or worse, brick my machine with it.

this is the point where my knowledge and experience runs out, so if someone has *any* ideas that would help, please share them..

thanks in advance,
bamdad
Title: Re: Pismo firmware downgrade?
Post by: FBz on September 18, 2021, 09:47:03 AM
Isn’t / wasn’t Firmware 4.1.8 THE update for the Pismo,
providing the “latest and greatest” (at the time) optimization
of hardware? (With a side order of RAM detect problems?)

Seems like maybe a clean install of the OS might be in order?
You could have some questionable RAM that needs replacing.
https://www.macworld.com/article/160527/appleram.html

Perhaps you’ve suffered some file corruption via that adapter.
Which adapter was bad & which adapter did you replace it with?

I’d back it up & do the OS re-install before attempting downgrade -
that’s just my approach… allowing the OS installer to now take into
account / recognize the 4.1.8 firmware and “adjust” accordingly.

Of course, could all be as simple as an NVRAM reset too?
Title: Re: Pismo firmware downgrade?
Post by: bamdad on September 19, 2021, 03:05:20 PM
Quote from: FBz
Isn’t / wasn’t Firmware 4.1.8 THE update for the Pismo,
providing the “latest and greatest” (at the time) optimization
of hardware? (With a side order of RAM detect problems?)
yeah, it's supposed to be, but the readme says it requires 9.1.. well it does not require it, but it leads to minor breakage.

Quote from: FBz
Seems like maybe a clean install of the OS might be in order?
You could have some questionable RAM that needs replacing.
https://www.macworld.com/article/160527/appleram.html
well, even though my install is tested and good, i tried a fresh 9.0.4 system folder just to see what happens, but it doesn't help. behaviour is the same. RAM works fine in every OS version (even 10.4), it's a recognised 1GB even with the new firmware, so i don't think that is the problem.

Quote from: FBz
Perhaps you’ve suffered some file corruption via that adapter.
Which adapter was bad & which adapter did you replace it with?
if you'd like i can link the new one - the old one was an 'IDE Pata' chinesium crap that i don't have the link to anymore, but believe me man, there is no corruption here. the system folder works flawlessly on my yikes G4 and there are no other telltale signs of a corrupted filesystem (e.g. RAM corruption problems, artifacts, freezes and the like).

Quote from: FBz
I’d back it up & do the OS re-install before attempting downgrade -
that’s just my approach… allowing the OS installer to now take into
account / recognize the 4.1.8 firmware and “adjust” accordingly.
i always have backups..  and, as i've explained above, i'm fairly certain it's not the OS. it even does the same booted with a freshly burnt CD from the garden.

Quote from: FBz
Of course, could all be as simple as an NVRAM reset too?
already tried that after i noticed the non-working brightness keys, but to no avail. to be absolutely sure i did it again..

so at the end of the day, thanks for the suggestions, but i think my original firmware downgrade idea is the only way to fix this. i assume there aren't any reports out there about this weird but not a lot of ppl upgraded the firmware, and probably nobody specifically uses 9.0.4 on their pismo.

best,
bamdad