Should I get a Rominator II?

[croissantking]

absolutely, im sure even with all the resources available today that to be able to patch the system boot process to do all that stuff would require some serious skill.


from memory, and im not a coder, ive just read about it but when the system file boots there are a bunch of PTCH resources that get loaded up to either add/replace specific macOS functions etc. this happens before the rest of the OS starts up btw. when system 7 came out there were certain functions on the core OS that Apple wanted to change however because of how the macOS works the only way some things could be added was by patching a pre-existing resource that's part of the boot up process to basically added the function they wanted that gets loaded before the rest of the system starts loading, Apple did this a lot over the following years and while im sure many other companies did the same it certainly wasn't a common knowledge type of skill set for a Mac programmer to have at that time.
So Mode32 as far as I understand it is a INIT but mostly its just a file for holding the actual 'data' that gets used to patch the system file with code to replace 24bit ROM routines with 32bit versions.
they possibly could have actually just patched the system file using a patching app and not used an INIT at all, however im just speculating here and might be wrong. there might be a reason im not aware of as to why they used an INIT.

Well, if you take the extension out of the extensions folder it won’t load anymore at early boot time. I assume the system file stays patched but checks if the INIT is present before continuing?

 

[croissantking]

So an update. I've moved the 'good' ROM socket from my IIsi to the SE/30 logic board. I also decided to reflow all the solder joints on the PSU, analog board and CRT neck board. (I was having some picture stability issues even after a recap of the analog board, so thought it would be wise.

In my haste to reassemble the machine I forgot to connect the flyback anode cap to the CRT and unfortunately when I powered it on it shorted out to ground against the metal cage in the photo and one side of the suction cup melted. I disconnected power as soon as I smelled the burning.

I reconnected the anode cap and powered back on, expecting the worst, but the machine seems fully operational with a good picture.

Have I been lucky? Can I just replace the suction cup from a donor CRT and get on with it? And presumably it's safe to run it with a slightly melted cup?

 

[croissantking]

Update: I did a bit of research and I think I will replace the cup before I use it any more.

 

[croissantking]

Since soldering in the new ROM SIMM socket that I pilfered from my IIsi, the error that I used to get in MacsBug 'The ROM symbol file could not be read due to an OS or memory error' has disappeared. This is a good sign.

 

[croissantking]

I want to tie up this thread with my conclusions, and thank everyone for their input.

I think all my stability issues came from that bad IOW line between the Glue Logic and the SCSI chip. The problem I had was that the issues were intermittent, but putting the logic board through the dishwasher finished off the remains of the marginal trace, allowing me to correctly diagnose the issue and run a bodge wire. I am running perfectly now.

If there ever was an argument for dishwashing your dirty logic boards, this is it.

 

[aplmak]

Man you are very lucky you didn’t get a decent shock there!!! Extreme caution when playing with crt anode caps/flyback! Just glad you and your Mac are safe! I’ve had my original Rominator for years!! I love it! But having a stock Apple IIsi ROM makes it feel more complete for me. BTW I’ve seen these new ROM clips online that are pretty cool!

 

[croissantking]

An update on my SE/30 adventures. I ran this board some more and my problems came back. I recently traced the RAM weirdness and instability to a bad F240 chip - swapped that out and the board is rock solid reliable now.

One of my clues was that I could run one bank of RAM without issue, but not two. The F240 logic connects the two banks together.

I’ve just got four other boards to fix now, this is my first fully working SE/30 board.

 

[croissantking]

The Rominator II that I acquired along the way made the process *much* easier, as it allowed me to test each bank independently of the other, and allowed me to run one bank of 64MB RAM with the other bank empty. You can’t do these things with the stock ROM. I also discovered that one of my 4MB modules is faulty which threw me off earlier on.

To reference the title of the post, I would 100% recommend anyone trying to diagnose SE/30 RAM issues to get a Rominator.