Sunday, March 26, 2017

Enigma Z30 Machine Simulator v2.0 Released

In time for the Vintage Computer Festival East (March 31-April 2), the Enigma Z30 Machine Simulator v2.0 is being released.

This 6502 program turns the KIM Uno into the cheapest enigma machine simulator out there.

This new version supports lever and gear stepping. The stepping logic has been changed so that the machine always steps when the rotors display 9, the ring setting has no effect on the stepping point. This is consistent with other enigma machines.

An optional, but very useful menu allows the machine settings to be changed without exiting the program. This previous menu had two options, the first one changed the rotor types, the second one changed the ring settings. It now has a third option so the gear setting can be changed as well.

This version has been optimized. The machine code has more functionality and is smaller than v1. When the menu code is added, the total program size changes from 703 in v1 to 714 in v2.

The program can be entered from the images shown below. The full source code can be downloaded at:

Z30 Machine only:

Z30 Machine Menu:

For the motivation behind the creation of this machine:

For the Paper Model showing the inner workings of this machine:

The image below is taken from the Paper Model file and shows a sample path through the rotors:

To read some thoughts on the recreation and cryptanalysis of this machine: