Help! Type 11 errors after adding FPU to LC III

[9646gt]

So after reading around type 11 errors occur on PowerPC machines running emulation layer for 68k code. My LCIII is a stock 68030 (overclocked to 33mhz with the resistor mod). It has a BlueSCSI V2 with 7.5.5 installed and has 32mb of RAM. I added a FPU tonight bought from this auction https://www.ebay.com/itm/2760990302...SR24dMOR4m&var=&widget_ver=artemis&media=COPY
Every since then I have went from being completely stable to getting type 11 errors when opening speedometer or macbench. I don't recall the error code I got in SimCity but it also crashes while sitting paused inside my created city. It seems maybe the FPU is to blame but I don't understand why. Do I need to reset PRAM or something? I don't have a PRAM battery installed. Virtual memory and 32but addressing are both turned on.

Just fired up techtool 1.0.4 and it shows no GPU installed

 

[Nixontheknight]

I'd say try adding a PRAM battery, as well as try reseating the FPU

 

[9646gt]

I wonder if I didn't jar the RAM loose. Even Netscape now gives type 11 errors. Seems anything that uses higher amounts of RAM throws the error

 

[Nixontheknight]

I wonder if I didn't jar the RAM loose. Even Netscape now gives type 11 errors. Seems anything that uses higher amounts of RAM throws the error

maybe, try reseating the RAM

 

[Melkhior]

I'll just quote my answer on reddit

On the MC68030/MC688882 relationship...

• chip markings are upper bounds on the frequency they have been validated at; they also have lower bounds but usually it's not an issue for 68k-era chips
• the communication between the '030 and '882 is done through the system bus of the CPU, so any issue here appears as bus errors
• the communication between the '030 and '882 is done using asynchronous cycles ('020 and earlier only use async, '040 and later only sync, '030 has both)
• as a consequence of the async cycles, the CPU and CPU can run at different speed, though in the LCIII they are fed the same clock so run a the same speed (Apple always used same clock FPU, but FPU on accelerators and add-on cards were sometimes running at different speed from the CPU).

More relevant to you, 40 MHz '882 in PLCC package are widely faked, same as 50 MHz '882 in PGA package. It's highly likely this is a lower grade '882 that was remarked to 40 MHz. Try lowering the system frequency back to 25 MHz, or even 20 MHz, to see if things improve - if they do, then it's definitely a fake. If they don't, the FPU might be defective (or there could be a reliability issue with the FPU socket/traces to the CPU, but that's less likely).

 

[9646gt]

Solved: I feel like an idiot but I pushed the FPU further into the socket and it still has some travel left and is now properly seated and functioning 100%.

 

[Melkhior]

Solved: I feel like an idiot but I pushed the FPU further into the socket and it still has some travel left and is now properly seated and functioning 100%.

That fake '882 works at 33 MHz? lucky you! Guess it was a "reliability issue with the FPU socket" after all

 

[9646gt]

That fake '882 works at 33 MHz? lucky you! Guess it was a "reliability issue with the FPU socket" after all

Right!? It seems to work flawless. Passed ever FPU benchmark at least. I guess I get lucky once in a blue moon. Everything else I try to do turns out like a video on the Action Retro channel on YT hah!