Macintosh II 68020 Rom Fun

[uniserver]

ok so thanks to Doug (olePigeon) for sending me some ROM Simms.

and thanks to my HAKKO 808 for making my life easy.

Thanks to bbraun for his idea, that I should do this.

I installed a rom simm.

here are my findings

Stock SE/30 Rom Simm - Works!!!

Dougg3 Rom /w Hacked IIsi rom - Does not work, Chime of death

Stock IIsi Rom Simm - Does not work, Chime of death

Stock IIfx Rom Simm - Works!!!

Kinda cool.

All i need now is to get my IIfx rom in and get it built like IIsi ROM is, -no ram size check - bootable 7.0.1 in ROM

[attachment=1]Screen Shot 2014-01-30 at 1.18.05 AM.png[/attachment]

[attachment=0]Screen Shot 2014-01-30 at 1.18.38 AM.png[/attachment]

 

[uniserver]

olePigeon sent me rom rimm slots.



before there was 4 sockets for rom chips.

I had to remove 2 of the 4 sockets.

I had to desolder those .. and desolder all the holes for the Rom Simm Slot.

Installed the new rom simm slot, I left the 2 farthest sockets isntalled because they were not in my way.( just made sure to remove those chips.)

+ I was not totally sure a Rom simm would even work. I am glad it does though…

Would assume with this rom in there.. I can now pop in a SWIM and it will acutely work

 

[CC_333]

That is neat!

I think with the FDHD upgrade, all one did was replace the four ROM chips and the IWM, so with the ROM SIMM containing a later, FDHD-supporting ROM, simply replacing the IWM with a SWIM chip should be enough.

And it's kind of odd that the supposedly universal IIsi ROM doesn't work. Do you have a full MMU chip installed? Maybe the architecture is too different (being a 68020, with every subsequent machine being an '030).

I wonder if this would work on a IIx? }

c

 

[uniserver]

yeah i think you are correct.

yeah the hacked iisi rom works in the IIx and IIfx.

I have not personally tried it in the IIx, only because my iix is next on my list to repair…

Yeah pretty sure this II i have has the MMU chip.

i really wanted the IIsi rom to work because i knew it contained the HD20 init…. i should check to see if the IIfx has the HD20 init..

just for giggles. but then i would have to open up my HD20 and go direct from pcb to mainboard… but hey, would have to be done anyways…

if BMOW gets the HD20 emu going… i would like to make a Nubus slot that has an external Floppy port on it just plugs into one of the onboard floppy ports. or just make a internal floppy port extender and connect that to a Nubus slot… right now i have a long floppy cable hanging out of the floppy port of my Mac II case For BMOW's Floppy Emu… it looks kinda honky. — but works!

 

[techknight]

Well because BMOW posted the ROM hook for the HD20 init, you can add it into any rom within the .Sony trap.