Epson PF-10 Portable Floppy Unit

PF-10 front view


Epson board name: KOALA
Epson Model: F10PA
Power Rating: 6V 1A
Power source: Rechargable batteries or C Type akaline (LR14)

The PF-10 is a compact floppy drive unit for the PX-8 and PX-4 computers. It uses a 3 1/2" floppy drive, but in 40 track mode. So the track distance (TPI) isn't 1/135" like all other 3 1/2" drives, but 1/67,5". By using only 40 tracks, it is a miniature version of the original QX-10/TF-15/TF-20 5 1/4" floppy format.

Internally the PF-10 contains a single board containing the processor, floppy controller and floppy control logic like stepper motor control and read/write head amplifiers.

PF-10 Koala board

PF-10 Block Diagram

Manual summary

Reconstructed power schematic

PF-10 Power Circuit

In this preliminary reverse engineered schematic the relation between the adapter plug, the rechargable battery pack and the dry C-cell connections is drawn. The power plug contains an extra connection which shorts with the plus side if no plug is inserted. Probably the battery pack is charged through the 6.8 ohm resistor.

Local links:

Last updated: 2019-10-09