With all due respect Ronald, but I have retracted my agreement with your argument regarding the reason why the FDC moved from #A00 to #BC48 and not to #BC00.That was for practical reasons, less modifications on the controller board since the “designers” of the mod did not want to mirror the controller like it does in the original configuration.
To move from #A00 to #BC00, only two very simple changes are needed:
1. Changing Blk0 on PL6/7 to BlkB (no problem, this moving #Bx outside the Atom instead of #0Ax was done anyway).
2. Changing the address selection line Y1 to Y2 on the controller card.
removing pin 14 of the LS138 (Y1, IC22) from the IC socket and then a drop of solder on the printed circuit board between pin14 of that IC socket and the adjacent pin 13 of the same IC socket.
That makes the entire move a fact!
N.B.:
Roland, could you, please, explain a bit more on what you mean by the "mirroring" of the controller, that you mentioned
Statistics: Posted by Louis.m — Fri Mar 28, 2025 10:37 pm