overclocking a 040/25

[matthey]

A 25 MHz 68040 can usually overclock between 30 and 40 MHz. A 40MHz 68040 can usually overclock from 42 to 48 MHz. There are probably some 68040's that will overclock to 50MHz but they would be newer. Look for a MC68040RC40 instead of XC68040RC40 and a later letter revision at the end as they may have a reduced size mask. There is 40 MHz 68040's on E-bay...

http://cgi.ebay.com/Motorola-68040-processor-XC68040RC40M-02E31F_W0QQitemZ230156322274QQihZ013QQcategoryZ4663QQtcZphotoQQcmdZViewItem

Be aware that at least 90% will not work at 50MHz and then will need excellent cooling and generate a lot of heat. The 68060 runs much cooler you should consider it as well. Check out Dave's Amiga (overclocking) Hardware page before doing anything...

http://members.iinet.net.au/~davem2/amiga.html

Do a lot of research before you do anything. Good luck.

[matthey]

The 68060 will fit in the same socket where your 68040 is now. The 68060 is 3.3V where the 68040 is 5V so you would destroy a 68060 if you put one in. You need a voltage regulator to reduce the voltage from 5V to 3.3V. There is probably a place already on your board for the voltage regulator and a surface mount jumper or two would likely have to be changed as well. See Dave's site.