Any PCBs available to re-house a 68040?

[Lektroid]

I have a very dead Apollo 1240, the battery severely leaked into 74F74 and when I removed it, pretty much every pad lifted, there is corrosion through the vias, etc, etc. It is certainly beyond saving (unless someone has a schematic?).

I was wondering if there are any PCBs available in which I could transfer the important parts over including the 040 chip in order to build a replacement accellerator? If there's a blank Apollo PCB, that would be even better, but I'm probably expecting too much there.

I just feel it's a waste of a good 040 chip which I would like to see running in my A1200

[Lektroid]

Guessing there is nothing available...

If anyone has a Apollo, and can map out the destinations of the pads from the 74F74 with a continuity checker, that way it can hopefully be bodge wired back into existence...

I really don't want to give up on this.

[Chucky]

I have done a complete replacementpcb for apollo. but as I promised I will not release the files for it. but I can help you with that area.. will try to dig up a photo of that part.

[Chucky]

[Lektroid]

Originally Posted by Chucky

I have done a complete replacementpcb for apollo. but as I promised I will not release the files for it. but I can help you with that area.. will try to dig up a photo of that part.

Thanks for the PCB layout image that's extremely kind of you. Do you sell the blank PCBs?

[Lektroid]

Quick update, I installed a replacement 74f74 took the +5V from the top of the bypass cap and did all the bodge wiring to reroute the pins to the necessary connections, but when I try to boot, the A1200 is dead, no action from the CF card or the floppy. just a blank screen.

I'm at the stage now where I probably need to scrap this idea and find another way to speed this A1200 up. Unless anyone has any other suggestions?

[Chucky]

have you tested all traces from the 74F74?

[Lektroid]

Originally Posted by Chucky

have you tested all traces from the 74F74?

Hi Chucky, thanks for your reply. As I mentioned in my opening post, most of the pads are lifted and missing (I have anchored it on with the 5 remaining pads), the vias are corroded so I cannot use the traces, instead I have used bodge wires in their place, and yes they now all go to the connections on the layout you provided (continuity checked), although there seems to be a layer missing in your image with the ground and +5V is, so I took a chance and used the +5V feed from the top of the bypass cap, although without the bottom trace shown, I'm only guessing this is the correct +5v feed. I also tried a different known working RAM stick in case that was the issue.

This card came inside an Amiga which I bought a few years ago as a job lot and has never worked, so I'm wondering if it even has the appropriate crystal oscillator in; the chip is rated at 25MHz and the crystal is 56MHz - seems a strange jump up in frequency. I have ordered a new crystal, but it's shipping from China, so could take a few weeks.

Did you ever manufacture PCBs for this? If so, do you have any available to sell?

[Chucky]

I have sent you a PM about that

[Jpor]

Originally Posted by Lektroid

Hi Chucky, thanks for your reply. As I mentioned in my opening post, most of the pads are lifted and missing (I have anchored it on with the 5 remaining pads), the vias are corroded so I cannot use the traces, instead I have used bodge wires in their place, and yes they now all go to the connections on the layout you provided (continuity checked), although there seems to be a layer missing in your image with the ground and +5V is, so I took a chance and used the +5V feed from the top of the bypass cap, although without the bottom trace shown, I'm only guessing this is the correct +5v feed. I also tried a different known working RAM stick in case that was the issue.

This card came inside an Amiga which I bought a few years ago as a job lot and has never worked, so I'm wondering if it even has the appropriate crystal oscillator in; the chip is rated at 25MHz and the crystal is 56MHz - seems a strange jump up in frequency. I have ordered a new crystal, but it's shipping from China, so could take a few weeks.

Did you ever manufacture PCBs for this? If so, do you have any available to sell?

The Apollo and Blizzard 040 cards use a 0.5 clock divider against the CPU. So 50mhz / 2 = 25mhz.

So bus runs at 50mhz but the CPU only runs at half that. There were Apollo 040’s at 40mhz running 80mhz crystals. Have owned both.

[Lektroid]

Originally Posted by Jpor

The Apollo and Blizzard 040 cards use a 0.5 clock divider against the CPU. So 50mhz / 2 = 25mhz.

So bus runs at 50mhz but the CPU only runs at half that. There were Apollo 040’s at 40mhz running 80mhz crystals. Have owned both.

It currently has a 56MHz installed so it will surely struggle to divide down. I'll order some 50MHz crystals from ebay now. Thanks for the info