Upgrading Powerbook 190 to 68040 with FPU?

[DominBear]

Can it be done?
I tried installing MC68040FE33V but no chime. CPU gets warm so it does something? Soldered LC back, works again.
Does the ROM care about it? They are pin compatible and the only difference should be FPU?

 

[Kai Robinson]

IIRC @This Does Not Compute tried this with a 540c and....no luck.

 

[Fizzbinn]

I recall reading somewhere about someone else doing this successfully, ...and something about only specific CPU part numbers working in Macs. Was it a 5V vs 3.3V thing?

https://68kmla.org/bb/index.php?threads/mc68040fe33v-source-spotted.30947/

PowerBook 500 Series full 040 CPU swap

You definitely should! I’m guessing this mod could be applied to the 190 and the Duo 280c. I was thinking that too.. actually I’m thinking if you took a 190 and replaced its screen with an active one from a 5300 (maybe even a CE?) and gave it a full 68040 you’d pretty much have the best...

68kmla.org

I think these are saying you need one of these:

MC68040FE25A
MC68040FE33A
MC68040FE40A

https://tinkerdifferent.com/threads/identifying-and-confirming-fake-68040-cpus-especially-the-l88m-mask.820/post-28861

and that the ends in V version actually doesn't have an FPU and is 3.3V not 5V.

 

[jmacz]

I have successfully done it on a PowerBook 540c and a PowerBook Duo 280c. @croissantking is the first I saw do it successfully (the above link is to his thread) on his 540c which is what inspired me.

Never tried on a 190.

 

[DominBear]

I tried these CPUs https://www.ebay.com/itm/226944137012

 

[DominBear]

Ah crap. It looks like V is 3.3V part. So I probably fried it a bit ;-)
I guess I need to find 5V part and try again.