Vfloppy is a disk simulator for the Epson PX-4 and PX-8. It uses the epsp protocol used by the Epson TF-15, TF-20, PF-10 and compatible disk stations. It is written in C for Linux, and should be portable to any *nix with standard libraries. Apart from the program, only a serial port and a cable to connect it to the PX-4 or PX-8 is needed.


The original version, written by Justin Mitchell and friends, consisted only of a TF-15 simulator for the PX-4 and a formatter to create empty images. The floppy images were files containing only the sector information of the tracks 4 and up, as the lower tracks are not used by CP/M. This format uses the extension ".vfd".


The versions 1.1 to 1.4 add support for the PX-8, and a read and write utility to transfer files between the images and the file system. Due to a bug, only file sizes below 32 kByte are supported by these utilities. These versions of the utilities use functions which make them less ideal for porting to Windows.

Emulators and D88

With the advent of the PX4 and PX-8 emulators, a new floppy image format appeared, Pasopia D88. As this format contains the complete floppy (also tracks 0 to 3), the simulator could in principle also support the HX-20 command set.

The 2.0 version of the simulator is an almost complete rewrite based on the Epson protocol description. This was done to make extension of the command set doable. By the way, only the basic commands for reading and writing are supported, the commands for formatting and disk copy are not. Having those too would be nice, but not really needed as these operations can be done on the host computer.

The emulator site has programs to convert Teledisk and ImageDisk images to D88.

New format, new possibilities

Because of this, and that there appeared to be no read and write utilities for the Epson PX-4/8 D88 format, I converted the simulator and utilities to this format. By the way, neither the simulator and utilities have any knowledge of the image structure, they only know where to read or write the data. The latest version finds actual sector locations instead of assuming interleave = 1.

Another advantage of the rewrite is that the source can be made more portable. The 2.0 version of the utilities can be compiled from the same source for both Linux and Windows.

The simulator does not buffer the mounted disk-images, but always reads or writes the files. This means the image read and write tools can be used to access the data as the PX-4/PX-8 sees it. No syncronisation or reload is needed.

Latest version

The source code can be found at GitHub

All versions are placed under the GPL. An exception are the files in the images. These may be copyrighted by Epson, DRI or others, and probably not GPL. If you have problems with this, please let me know or just delete the offending files...

More info:

Generic links:

Also see the sourceforge page

Latest update: 2022-06-11