Mac OS on ANS - Modding a ROM DIMM

[robin-fo]

So, with all of the wackiness of porting things like Windows NT to PPC Macs, are we going to get modded ROMs for PowerMac 8500/8600/9500/9600 systems that can now run that funky AIX??!

Would be fun to play with!

That would indeed be cool!

 

[gogopuffs]

@Big Ben - would you be willing to document via shaky-cam mobile phone and upload to YouTube or Internet Archive and show the bootup/build process???

Thanks!!!

 

[Big Ben]

I’m afraid there is nothing special about booting MacOS it just boots like any other Power Mac: grey screen, happy mac and so on.
Open Firmware stuff was related to improper configuration.
Front LCD screen is disabled so nothing to see here too.

As far as building a ROM DIMM, I won’t be able to build others until someone design a new pcb board.

 

[Classic_II]

I just wanted to say thank you to Big Ben, John, joevt, stynx, dougg3, Eric & jocketlill.

It is absolutely amazing to see everyone come together to make something amazing happen!!!

If anyone is thinking about making a custom rom board, let me know. I was thinking of reaching out to Joe to see if we could get a blank SIMM created.

 

[joevt]

bitsavers website has PowerSurge Flash ROM pictures and schematics.
http://bitsavers.org/pdf/apple/powerpc/PowerSurge/ROM_Flasher/

 

[winocm]

I forced the boot into Mac OS with setenv boot-command bye

Now the ANS just boot like a normal Mac. To boot AIX I suspect you only have to press Command-Option-O-F and type boot to start AIX.

I tried to install a video card but it wasn't detected, maybe a bad contact or a non-working card as it was untested.

Fun-fact the Cirrus Logic 54m30 chip is limited by... software and hardware (sort-of), because the chip is designed for little-endian operations and the driver lack implementation of endianess convertion.


Source: https://wiki.preterhuman.net/ANS_Hardware_Developer_Notes - page 9 section 2.8

Doc also contains CPU board pinout!

On that note, I ended up making an OpenFirmware driver for the Cirrus Logic GD54{30,34,36,46} cards based on the FirmWorks codebase and some taking apart of the ANS code.

It seemed to work fine when I was emulating the Viper CHRP firmware.

If it's useful for anyone else, here you go.