THE FSD-1 SINGLE FLOPPY DISK DRIVE

     I don't have a schematic for this drive. It is apparently a clone of the 
Commodore 1541-II REV 4 as it uses the same DOS ROM (CBM 355640-01, checksum 
hex 641F) code in a single 16K IR EPROM. The drive has an internal switch-mode 
power supply and uses a Newtronics twist-door mechanism. 
     Note: if you need to swap out the mechanism for any reason, it's identical 
to ones used in a 1541, but the stepper motor wires (the white six pin plug) 
color codes don't match! Perhaps this was done to skirt copyright issues with 
Commodore... I don't know. Those wires -must- be swapped around to match the 
old FSD mechanism. Use a straight pin to slightly compress the tabs in the tiny 
slots of the connector so the pins can be pulled out. If necessary, gently bend 
the tabs out again slightly so the pins stay in place when reinserted in the 
connector. The other three connectors appear to be wired correctly. Just make 
sure you put them back with the proper orientation. There is no keyway to 
prevent reversing them! The black connector for the R/W head wires is marked 
with pin 1 as is the silk screen PC board. The two tiny switches on the bottom
of the drive case are for device select, as on a Commodore 1541-II. The drive 
was shipped with both switches up (on) as device 8.