Macobyte
Active member
Here’s a mystery I’m trying to figure out.
I have an SE/30 with a stock logic board with a BMOW ROMinator II and 128MB of RAM. Also in this machine is a 50MHz DiiMO and a MacCon Ethernet card, and it all works perfectly.
I had a spare SE/30 logic board with trace damage which I sent to Will of CayMac Vintage to transplant to a SE/30 Reloaded board (which he did a fantastic job on, by the way).
I have a spare stock SE/30 ROM and 8x 1MB RAM SIMMs (8MB total) which go with this spare board and I sent along with it to Will for use/testing.
Before I sent the board and ROM and RAM, I tested the (stock) ROM SIMM in my good board and got a bus error on boot, after the “Welcome to Macintosh” screen. Thinking it didn’t like the 128MB of RAM, I swapped in the eight 1MB SIMMs. Same result. Either set of RAM worked fine with my ROMinator II. Advising Will of this I sent everything on. He transferred everything to the Reloaded board and tested it with my stock ROM and 8MB of RAM in his SE (effectively a SE/30 with my Reloaded logic board connected) and it worked fine. I believe he even hooked up his TechStep to verify everything was functioning correctly.
I received the Reloaded board back and it works great; I swapped it into my SE/30 and installed my usual configuration of the ROMinator II, the 128MB of RAM, and my DiiMO and MacCon. Curiously, I then swapped my stock ROM SIMM in (with the 128MB of RAM), and I got the same pesky bus error again. So on my other, stock logic board which was in my SE/30, I installed the stock ROM SIMM and the 8MB of RAM and tried that… again with a bus error.
This stock SE/30 ROM SIMM has been tested in two different known-working logic boards, each with 8MB and 128MB of RAM installed, and it has thrown up a bus error in every case except when the Reloaded board was installed in an entirely different SE(/30) enclosure, in which case it worked fine.
Given the bus error message, you may assume it has something to do with the boot drive, and that is another key difference as my SE/30 has an internal SCSI2SD v5.2 running System 7.5.5 and Will was booting off an external BlueSCSI running (I believe) 7.5.3. However, I suspected the boot volume could be the culprit when I originally tested the ROM before sending everything to Will… I swapped in the Mac’s original, working Quantum Fireball drive running 7.5.5; I got a bus error there as well.
So what’s the culprit here? Could there be something unique to only my SE/30, not related to any component on the logic board, which could cause a bus error with a stock ROM while not causing any issue at all with a ROMinator II (and 128MB of RAM and a DiiMO) installed? How do I even begin to troubleshoot this? Any suggestions or input are welcome and thanks in advance.
I have an SE/30 with a stock logic board with a BMOW ROMinator II and 128MB of RAM. Also in this machine is a 50MHz DiiMO and a MacCon Ethernet card, and it all works perfectly.
I had a spare SE/30 logic board with trace damage which I sent to Will of CayMac Vintage to transplant to a SE/30 Reloaded board (which he did a fantastic job on, by the way).
I have a spare stock SE/30 ROM and 8x 1MB RAM SIMMs (8MB total) which go with this spare board and I sent along with it to Will for use/testing.
Before I sent the board and ROM and RAM, I tested the (stock) ROM SIMM in my good board and got a bus error on boot, after the “Welcome to Macintosh” screen. Thinking it didn’t like the 128MB of RAM, I swapped in the eight 1MB SIMMs. Same result. Either set of RAM worked fine with my ROMinator II. Advising Will of this I sent everything on. He transferred everything to the Reloaded board and tested it with my stock ROM and 8MB of RAM in his SE (effectively a SE/30 with my Reloaded logic board connected) and it worked fine. I believe he even hooked up his TechStep to verify everything was functioning correctly.
I received the Reloaded board back and it works great; I swapped it into my SE/30 and installed my usual configuration of the ROMinator II, the 128MB of RAM, and my DiiMO and MacCon. Curiously, I then swapped my stock ROM SIMM in (with the 128MB of RAM), and I got the same pesky bus error again. So on my other, stock logic board which was in my SE/30, I installed the stock ROM SIMM and the 8MB of RAM and tried that… again with a bus error.
This stock SE/30 ROM SIMM has been tested in two different known-working logic boards, each with 8MB and 128MB of RAM installed, and it has thrown up a bus error in every case except when the Reloaded board was installed in an entirely different SE(/30) enclosure, in which case it worked fine.
Given the bus error message, you may assume it has something to do with the boot drive, and that is another key difference as my SE/30 has an internal SCSI2SD v5.2 running System 7.5.5 and Will was booting off an external BlueSCSI running (I believe) 7.5.3. However, I suspected the boot volume could be the culprit when I originally tested the ROM before sending everything to Will… I swapped in the Mac’s original, working Quantum Fireball drive running 7.5.5; I got a bus error there as well.
So what’s the culprit here? Could there be something unique to only my SE/30, not related to any component on the logic board, which could cause a bus error with a stock ROM while not causing any issue at all with a ROMinator II (and 128MB of RAM and a DiiMO) installed? How do I even begin to troubleshoot this? Any suggestions or input are welcome and thanks in advance.