It was determined that this needed to be posted here on AppleFritter as well in the event that there might be a 'FritterCritter poking around who may want to get involved.
My post on 68kMLA:
Protocol7 and I traded quite a few PMs on this one.
** There is macbootable Sil3112 firmware. FirmTek SeriTek/1s2 is the card. aka Sonnet Tempo SATA (TSATA). These cards can boot pre-G3 PowerMacs and boot 7.6.1.
206 The Tempo SATA card does not seem to work properly in my Power Mac G4. Do I need different firmware? Apr-25-10
Some customers have experienced problems with the current version of the firmware in older G4 machines. Sonnet suggests downgrading the firmware to the Version 5.13, which can be found at http://www.firmtek.com/download/SeriTek1S2_513.zip
** newest recommended FirmTek firmware (5.13) is 136k. This is too big to fit on any Sil3112 card currently tested and also a crossflashed Sil3512 based card. FirmTek firmware 5.11 is 131k, still too big.
Either need to find a bigger chip to solder onto the card or reduce the size of the firmware or find a card that has a bigger chip already. Protocol tried multiple times to reduce 5.13 it but no luck yet. Not sure if he tried with 5.11 since then though.
(The Silicon Image updates are 128k, Weibetech's are only 64k, but we need the FirmTek one)
** There was an OS9 flasher mentioned in a MacGuru article. It has not been located yet.(hoping that it might come with a smaller fimware file)
Props to Protocol7 for his legwork searching the vast internet and editing the ROMs.
And RIP to the new-in-box 3.5" floppy disk I seem to have killed with all the flashing activity.
Protocol7, if I have missed anything or if you have updates please post it.
To others, if you want to try to reduce a firmware or have a card that can take a full-size FirmTek firmware please let it be known. :)
And some additional info posted by protocol7 that looks like it may have significant potential!:
There's also a Japanese card that uses the Sil3112 and appears to only have a 512kbit eeprom (64kB firmware file). Finding a firmware from that would be immensely helpful. I can't say with any degree of certainty that the Mac cards are otherwise identical to the PC ones. It'll take a suitable firmware file to find out for sure.
So that is about that. In the PC world You see people crossflashing Sil3512 and Sil3112 cards so if you can only get one, you may still be in luck.
Not really sure what else I should add here, but if you have any questions or comments please do post.