I bought a notebook of COP400 development info and disks off ebay. The disks turned out to be 8", so I bought an NEC FD1165A floppy drive. This drive is easier to use than other 8" drives, because it only requires 5V DC and 24V DC, and has a 50-pin DIL connector instead of an edge connector. I found a manual for the FD1165 which is very similar, and the NEC APC System Reference Guide has the pinout info for the FD1165A.
I used a PIC microcontroller to control the drive select, head load, side, direction, step and low write current signals, and read the ready, track 0 and write protect signals. The program steps to each track and waits 1 second; since the disk rotates at 360RPM, that's 6 rotations. I had to replace the 150 ohm termination resistors with 1K to get it to work reliably- the PIC couldn't quite sink enough current to overcome 150 ohms.
I captured the index pulse, read data and step signals with a Saleae Logic 16 at 25MHz. I exported the capture as a CSV file, and wrote a program to decode the FM data and read the file data.
I was able to read all the sectors successfully from 3 of the 4 disks; the 4th has obvious physical damage, so the data may not ever be readable.
COP400 Product Development System User's Manual
COP400 Product Development Software Information
QuikLook User's Manual
COP400 In-Circuit Emulator User's Manual
COP400 PDS diskette format info
program to read the disks
The following diskette archives contain FM-decoded bitstreams of each track (diskbits_s0_tn.bin), a disk-image file (disk.bin), a logfile from the dumping process (floppy.log) and the files from the disk.
COPS Tester PDS Master diskette
COPS Tester PDS Test diskette
COPS Tester ROMCHK diskette
back to COP400 page
back to Decap page
back to Home page