HARD DISK DRIVE TO HARD DISK DRIVE CONTROLLER READ/WRITE SIGNALS CONTROLLER 10 PIN CONNECTOR J2 TO HARD DISK DRIVE 20 PIN CONNECTOR P2 1 (NOT USED) 1 (NOT USED) 2 2 3---(+MFM WRDATA)------------------3 4---(-MFM WRDATA)------------------4 5 5 6 6 7---(+MFM RDDATA)------------------7 S---(-MFM RDDATA)------------------S 9 9 10 (NOT USED) 10 ----I 11 / 12 / 13 / 14 / 15 /--- (NOT USED) 16 / 17 / IS / 19 / 20 ----I 8-6