Custom SE/30 ROM: Original Gestalt ID, HD20 support, 32bit clean and RAM/ROM check disabled?

[BadGoldEagle]

Hello

I'm going back home for a couple of weeks in March so that means spending more time with my Macs!

I had Mode32 installed on my SE/30 but for some reason it was the wrong version for 7.5. Having the wrong version installed can completely screw up your hard drive. And in my case, it kinda did. I removed the old version and reinstalled the correct one but unfortunately, the computer boots in 32bit mode only 10% of the time. I don't want to reformat the hard drive and lose 30+ years of work. Plus having a 32bit dirty ROM isn't necessarily great. 

So, TL;DR: 

I'm going to get a GGLabs MACSIMM (if they ever manufacture new ones... otherwise I'll have to get it done somewhere else) but first I'd like to know if there is a modified SE/30 ROM floating around somewhere that has the following features:

- 32 bit code

- SE/30 Gestalt ID (#9): I'm running a small hack for 7.5 that shows what machine you're using when you click on "About this Mac" (like on 7.1) and I don't want it to show a IIsi or something...

- ROM/RAM check disabled

- HD20 support (for transferring files on the Floppy EMU in HD20 mode)

I've looked online, I'm sure I've come across one that fits my requirements before but I can't find it now... Any help appreciated!

Thanks!

BGE

 

[Bolle]

Gestalt shouldn’t change with a different ROM.

I can send you a bare ROM SIMM that takes 29f040 chips for a total of 2MB if you want.

No need to pay too much for a GGlabs SIMM

 

[BadGoldEagle]

PM sent!

 

[BadGoldEagle]

Back to the main topic: 

Apparently the ROM that has (nearly) all the features I'm looking for is the one from the IIsi, but it has the RAM check enabled. Any way to remove that with an hex editor? I found several ROMs online but they have additional features I don't really like. I'd rather make my own if that's not too difficult.

In other news: I've just learned that the Gestalt ID won't change with a different ROM, so that's one thing covered. And I might still go with the GGlabs SIMM as they offer free flashing service (I don't have a programmer so I'd have to add the cost of buying one and the chips to the whole thing... so it might be more expensive in the end).

 

[BadGoldEagle]

Problem solved: see my comment on this thread 





Here is the ROM file I'm going to use

View attachment iisi+nomem2.bin