By the way, the machine has 64 mb, but I can see three memory banks in the motherboard. I can't see them very well but I think they are all equal, among other things, in capacity. But you can't divide 64 by 3. Any ideas???
If I were to hazard a guess, you've either got a bad chip, or you're not seeing all of your memory. If you do indeed have a towerized A4000D, and the 68060 accelerator, you should have TWO spots that have memory. The normal A4000D (and I think the A4000T) was limited to 16mb of ram and 2mb of chip memory. If you're seeing 64mb of fast memory, it could be that you have two 32mb sticks in the accelerator, with none on the motherboard, and they have to be in pairs, so the third one just isn't detected (or is bad). Or you could have 3 16mb ones on the accelerator, and the 4 4mb ones on the motherboard would give you 64mb of fast memory, but I am pretty sure you have to have them in pairs...
Stupid memory... mine is failing!

It's funny that SIMMS had to be in pairs, then DIMMS didn't, then all of a sudden they don't HAVE to be, but they SHOULD be in pairs for dual-channel, then now newer systems handle triple channel as well...
Otherwise, I really can't figure out how you have 3 chips with 64mb of ram. And where is the Chip memory?
slaapliedje