Quote:
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?
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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.
