32-bit Clean ROM

[just.in.time]

After years of waiting I finally got around to getting a 32-bit clean ROM SIMM for my SE/30 (I believe it is from a IIsi).

The real conquest is that I now have Mac OS 8.1 running smoothly on my SE/30

 

[Crutch]

Do you see any weird video artifacts on startup with the IIsi ROM? I tried that recently and always saw simasimac-looking scrambled pattern for the first few seconds before I got a happy Mac. Made me nervous. 

 

[360alaska]

Do you see any weird video artifacts on startup with the IIsi ROM? I tried that recently and always saw simasimac-looking scrambled pattern for the first few seconds before I got a happy Mac. Made me nervous. 

Pretty sure video artifacts are completely normal for using a IIFx rom, a IISI rom will boot right away.

 

[just.in.time]

So interestingly, about 2/3 cold boots have the artifacts at boot time for a few seconds, then they go away and happy Mac shows up.

That said, I think there are several versions of the IIsi ROM, so it may vary from rom to rom. Mine starts with rom chip 341S0820.

 

[olePigeon]

Why do people want the IIsi ROM over, say, the IIci ROM?  I experienced no video artifacts when using a IIci ROM.  Did IIsis come with a ROM?  Are they just really common?  I'm not aware of any IIcis that shipped with a ROM SIMM, but it's trivial now with the DougG3 ROM.

 

[just.in.time]

Personally, I like my ROM SIMM to fit without having to use shims of some sort to hold it in place. Apparently the board thickness the original SIMMs used is hard to come by now.

Some IIsi models came with SIMMs, some had the ROM soldered in. So when people say the are using a IIsi ROM, they generally mean the original Apple branded SIMM that has proper fit. The IIci ROM code can be used, but only if flashed to another product. Not on an original Apple part.

As for the artifacts, they are really a non issue. They show up for 2 or 3 seconds, then disappear completely and the happy Mac logo appears and boot up continues as normal.

 

[olePigeon]

Ah, OK.  I have the original red ROM.  I didn't experience any issues with board thickness.

 

[Von]

Gamba2 documented the SIM chip numbering here

I used this when I was sorting through my stack of SIMs in June:



Top 3 are all IIfx per chip numbers and tattle tech reporting 32-bit clean. The top left does not boot...does anyone know if a SIM can reflashed?

Here is the back of the SIMs:



When I boot to the IIfx SIMs I get different artifacts...here is one:



And the other:



The machine has 128MB RAM so it takes some time for the RAM check to complete. I'd love to find a way to skip this but I don't think there is unless you are using a ROMinator.

 

[olePigeon]

If you ever stumble upon a Daystar accelerator, you can disable the RAM check via the Daystar Control Panel.

 

[Von]

If you ever stumble upon a Daystar accelerator, you can disable the RAM check via the Daystar Control Panel.

Good to know. One of the SE/30's is getting the on-board 50mhz installed soon so I will look for that setting in the DayStar CP.

 

[Crutch]

Ahh my SE/30 gets the same as the first video artifact shown above (from the IIfx ROM) even though it’s using the IIsi ROM ... but I also have 128MB RAM so maybe it’s just due to a slow RAM check? It seems harmless but aesthetically imperfect. Oh well. 

 

[just.in.time]

@Crutch @Von my SE/30 also does the top artifacts for ~3 seconds. I have 20mb of RAM installed, for reference. I also have a 40mhz 030 upgrade so RAM check goes decently quick (compared to before).

@olePigeon yeah, some people get lucky and don’t need anything, others do require shims else the machine won’t boot. I decided to not take the gamble since I already had a SCSI2SD as well. I may still pick one up at a later date to play around with, but for now the IIsi SIMM that I got on the cheap gets the job done.

THAT said, I do have the Rominator 1 installed in my Mac Plus and absolutely love it. Highly recommend to anyone with a 128, 512, or Plus.

 

[olePigeon]

You could always redo the solder on the pins so it's extra thick.

 

[just.in.time]

@olePigeon I was thinking replacing the slot with one fit for the modern board thickness. Part shouldn’t be too expensive.