So the Floppy for the PX8 is specialized for a CP/M
host it's not running
CP/M itself as there is not enough ram alone to qualify.
To clarify the Epson
floppy drive issue, there were three products:
TF-20 - Z80 based, 64k RAM, 2k ROM, boot from disk
TF-15 - Z80 based, 2k RAM, 8k ROM, runs from ROM
PF-10 - 6303 based, 2k RAM, 8k ROM, runs from ROM
The TF-20 supported the commands used by the HX-20 and the PX-4/8
The TF-15 and PF-10 only supported the PX-4/8 commands.
The TF-20 used the boot tracks of the disk to load some OS and a program
which made it a serial 'file server' for the host. The OS could very
well be a slimmed down version of CP/M.
The HX-20 commands are file based and were issued mainly from Basic. The
Basic
extension is also on the boot disk.
The PX-4/8 commands are sector based and issued from CP/M.
All devices used the same protocol, epspd and baud rate. The same
protocol was used internally in the HX-20/PX-8 between the various
processors. The HX-20/PX-8 external video device also used it.
The TF-15 and PF-10 are both ROM based. The TF-15 used the same housing
as the TF-20. As this resembled the QX-10 computer, the origin of the
TF-15/20 product was probably to provide two extra floppies for this
computer.
For those interested
http://www.xs4all.nl/~fjkraan/comp/tf20/ contains
some info on epsp and the TF-20 boot disk.
Fred Jan