A3640 rev3.1 68040@25mhz CPU Amiga

[Darrin]

I replaced the A3640 in my A4000 with a GVP 68040 40MHz & 64MB RAM.  I took the A3640 and put it in my A3000 desktop and according to SysInfo there's a big speed increase.  Unfortunately I can't really tell you how it "feels" as I haven't put it to much use apart from testing some floppy disks created using a Catweasel.

One thing you will need to do is to modify the heat sink on the CPU.  The one fitted is too tall to put the floppy drive housing back on, so you'll need to find a low profile one.  I got one off an old Intel processor and it works a treat.

Also, don't forget to move the two jumpers on the mobo so that the A3000 knows to use the card in the CPU slot.

[Darrin]

BUT:

In an A3000D they get very hot (unless you can find an L88M chip) and really require you cut vent holes in the floppy disk mount plate.

Nice tip, I'll give that a go when I have some spare time.