13 May 2021 13:28
|i run my v500 on a rev5 A500 board, and it's fine with 512k chip ram. i did get hold of a minimega 2meg chipram board with the later agnus on it - but that leads to vampire location problems.|
having enough of a riser to lift the vamp over the minimegachip board means the keyboard doesn't fit - and the case doesn't go back together.
so i moved my vamp externally with a Lazarus board from Arananet. But the side expansion port that the lazarus board connects to on the rev5's - doesn't have the 7Mhz clock signal that the Rev6 and higher A500's do have there, that the vampire needs.
so i ran a jumper wire from the now empty 68k socket to the lazarus edge connector.
so i now have a 2meg chipram rev5 vampire powered A500 with the keyboard fitted and case closed. just i can't ever remove/refit the lazarus board without having to open it up to re-attach the jumper wire.
however. tldr, yes 512k chip will work fine, just you'll only have 512k chip. :)
(oh, i'm not sure what timing issues i was introducing, but i did have a load of du-pont male-female wires going from the 68k socket to the 68k connector on the vamp. it worked amazingly. andi could close the lid on my A500 with everything inside. just i didn't want to risk those vampire pin legs hence the lazarus board)