Another repaired A3640

At long last I've got around to replacing the caps on my original A3640.

A couple of the caps look slightly off centre but they all check out ok.

I nearly crapped myself when I put it in my spare 4000/30 and it wouldn't boot up

I'd forgotten to switch over from internal clock to external clock :jester:

Dave G 8)

Re: Another repaired A3640

@Davideo

Those jumpers are easy to forget, Just ask Zetr0 :jester:

Nice work mate

TC

Re: Another repaired A3640

WTF? A 3.1 board without the overclock hack?

Re: Another repaired A3640

Overclock hack? Tell us more

Re: Another repaired A3640

Same here?

Is there a bonus to be had with a standard 4000 with the hack?

My other 4000 has got a Warp fitted to it with extra RAM on board

The A3640 I inherited with the 4000/30 has been buggered up by its previous owner. There are no solder tags left :banghead: Anybody got any ideas how to sort that one out?

Dave G 8)

Re: Another repaired A3640

davideo said:

<snip> There are no solder tags left :banghead: Anybody got any ideas how to sort that one out?

Dave G 8)

Click to expand...

Yeah, ....send it to Zetr0.

Kin

Re: Another repaired A3640

Dave, just look where the solder tag goes to - i had the same problem... I ended up finding the right place to solder to using a via. There was enough pad left to check continuity with a multimeter, and double check with the schematics

Bear in mind the schematics are online too.

Re: Another repaired A3640

I would like to thank rkauer that put me onto the hacking of the A3640.

Essentially what you do is hack the delay line so that you can clock-the-card up from 25mhz upto 40mhz.

not all cards will go as fast as 40mhz, some (few) wont clock-up at all, but its such a cheap easy mod for a large benefit.

Recently I sold such a modified card with an 40mhz compatable full core 040 to MagerValp, unfortunately I never got round to doing a full test on its range.

heres the card


here is the delay line hack (in Commodore Blue 30 Awg)


here is the Osc hack: Machine turned (gold plated) socket pins for changing of the Oscilator (crystal)


here some results that MagerValp got at 33mhz




and theres more on MagerValps experiments


@Davideo

I can help with the loss of the pad m8 (and delay line +OSc socket), I am working on DDNI's A630 this week, but I can get a look at it next week =)

Re: Another repaired A3640

@Zeets

The other board looks as though it's had some sort of hack on it already.

I'll see if I can get a picture added to this thread tonight showing the other board.

I'll look into chiarks suggestion and see what I can make of it - failing that it could finish up on your doorstep yet Zeets.

Dave G 8)

Re: Another repaired A3640

No worries m8, anything for a fellow AmiBayer / EAB'er =D

Re: Another repaired A3640

Here's the other board. It's a version 3 with a hack of sorts on U200.

Any ideas on if this is a legit hack or not? and what it's for?

I should learn to look aroound the internet better before asking questions :ROTFLOL2:

Just found this on Anthonys site


Dave G 8)

Re: Another repaired A3640

@Davideo

I have no idea what that hack is for... to be honest it looks mashed, I would be inclined to repair that lol