34 Pin IDC to 25 Pin Female D-Sub floppy drive pin mapping for Magic Super Griffin
(and probably MGD2, etc)
I cracked open my Magic Super Griffin today after finding an old external floppy drive (FDD) that I wanted to hook up to it. I was expecting to have to look at chip pinouts and signals to figure out which pins were which on the 25-pin connector but to my surprise there was space on the motherboard for a 34pin IDC connector. So the signals can and pinout could be taken directly from that. The FDD controller chip on the SMG, for reference, is a socketed (!) Motorola MCS3201FN - http://www.datasheetarchive.com/pdf-datasheets/Datasheets-111/DSAP0039438.html. The datasheet reveals that the controller can handle up to 1.4M drives too.
\ 13 12 11 10 09 08 07 06 05 04 03 02 01 / \ 25 24 23 22 21 20 19 18 17 16 15 14 /
The pins above are taken looking directory at the female pin (cable) side of the D-Sub connector.
The pins of the IDC connector are numbered from left to right, vertically, from the component side of the board.
01 02 03 04 … 33 34
The pin mapping is thus:
D-Sub - IDC - Signal 01 - 01,03,...,33 - GND 02 - 08 - /INDEX 03 - 26 - /TRK00 04 - 28 - /WPT 05 - 30 - /RDATA 06 - 34 - /DSKCHG 07 - NC - NC 08 - NC - +5V 09 - NC - NC 10 - NC - NC 11 - 16 - /MOTEB 12 - 22 - /WDATA 13 - 24 - /WGATE 14 - 02 - /REDWC 15 - 32 - /SIDE1 16 - 18 - /DIR 17 - 20 - /STEP 18 - 01,03,...,33 - GND 19 - 01,03,...,33 - GND 20 - 01,03,...,33 - GND 21 - 01,03,...,33 - GND 22 - 01,03,...,33 - GND 23 - 01,03,...,33 - GND 24 - 01,03,...,33 - GND 25 - 01,03,...,33 - GND Shield - 01,03,...,33 - GND
With the above information I'm now able to make a suitable cable to connect up any standard PC floppy disk drive. I don't know which model drives are actually compatible. Though I would suggest checking out the Datasheet for the FDD controller chip. If you have any success please let me know so I can share the information with others.
BTW, If you didn't know already a Super Magic Griffin is a PC Engine console backup unit. With it you can load dumped ROM images into the SMG and then run them on your PC Engine console. The unit is basically a ROM emulator with FDD and Parallel I/O connections. They were manufactured by Front Fareast Co. Ltd. (Taiwan).