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LC 475 - switch from 68LC040 to the 68040 with FPU, what do I have to consider ?
Posted by: mkuenzel on 2023-09-04 05:27:34
for example on E**y there is an offer for a "Motorola XC68040HRC25M Socket PGA179 CPU 25Mhz". Should this cpu work ?
Posted by: Phipli on 2023-09-04 05:42:55
for example on E**y there is an offer for a "Motorola XC68040HRC25M Socket PGA179 CPU 25Mhz". Should this cpu work ?
It's just a straight swap. The only difficult is making sure you take care removing the old CPU. Best to use something thin that you can slip into the gap and then rotate to lift. Avoid screwdrivers off possible, avoid "twisting" if possible. Ideal is a dedicated CPU removal tool, but they seem hard to find.

Best might be a plastic prying tool.
Posted by: mkuenzel on 2023-09-04 10:32:09
I already removed the old cpu without problems. Currently the board is prepared for washing and recaping.
Posted by: ArmorAlley on 2023-09-04 10:54:34
Do look into upping the bus-speed to 33MHz as well as getting yourself a 33MHz 68040 processor.
Posted by: MacKilRoy on 2023-09-04 11:11:53
The HRC processor should be fine if you choose to operate it at 33mhz with an overclock. It’s supposed to be a high temperature variant, meaning it runs at a lower temperate at stock speeds, apparently. I’d recommend a heatsink though, regardless.
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