The MFD4 allows the installation of two internal floppy drives when rehousing an A1200 motherboard. The MFD4 is a modified floppy cable with three floppy headers, where one is installed on the internal fl oppy port of the motherboard, as well as a small PCB which connects to the chip labeled U8. On the PCB a jumper block can be found, labeled DF1:, DF2:, and DF3:. Only the DF1: jumper is active.
Cable Diagram
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DF1: DF0: Internal floppy port