VMU2PC

VMU2PC is a collection of software allowing the transfer of data between the VMU and a PC. The package contains two programs, Serial2VM, written by Soeren Gust, which uses a serial port with a Atmel microcontroller to convert the logic from the 5v of a typical PC to the 3.3v logic of a VMU. Secondly, VMU2PC, written by John Maushammer, which uses the a parallel port and a custom cable to reduce the voltage for the VMU. Gust's software was used as a basis for Maushammer's approach. You can download it here.

Serial2VM

This approach uses an Atmel AT90S8515 to convert the synchronous serial protocol from the VM into the normal asynchronous serial communication. Sadly the firmware required to create such a cable has yet to be found and likely lost to time.

VMU2PC

This approach uses a custom made cable to transfer the data via a parallel port. You can read about how to create the cable here. The program however it relies on processor loops for timing, which might not be very useful on modern hardware.

Further Reading

Maushammer's page on VMU2PC [1]

Gust's main page on VMU [2]