A3640 CPU for A4000(T) running at 32mHz on ebay

[tonyvdb]

Go here for listing.

[Akiko]

Is that nice looking tower going up next?  :-D

[tonyvdb]

LOL, nope ;-)  Just getting rid of some things lying around. I hung on to it just in case I had problems with my Cyberstorm but that is not likely so I might as well get rid of the A3640.

[amiga92570]

did you just replace crystal or did you modify delay line? Also what speed processor are you using. I Have a couple 3640's and was going to overclock one with a 33mhz 040 but wasn't all to sure how stable it was.

[tonyvdb]

The work was not done by me I bought it 3 years ago this way but it works really well. The crystal is replaced as it says 64.00000MHz on it (meaning cut it in half at 32MHz)I do not know what else was done as I dont know what to look for. The prosessor is a 68040 as usual.

[hardlink]

I didn't know you could hack the A3640's that far. I would be a neat thing to put in a A3000 desktop!

[amiga92570]

I know you can get them to about 33mhz, but you have to make a delay line modification. Some still do not work correctly, but I couldn't help to think that this was due to the 25mhz chip heating up. I have been trying to find someone who has overclocked it and installed a 33mhz chip to see if it still has the same problems. Have you unclipped the heat sink to see if it has a 25 or 33mhz chip? I really want to know.  :-D

[tonyvdb]

I'm not willing to remove the heat sync as I dont want to mess with it. It works and thats good enough for me. I do know that there is a little jumper wire that was not on my other 3640 that I sold a year ago. It looks to be done very professionally as the solder points are just perfect.

[amiga92570]

thanks, thats the delay line mod. I may give it a try.

[Karlos]

You sure that's not 32MHz? ;-)