Dear Gary: This is marvellous! I used to work quite a bit on a 3600 in 1968, and it is good to hear that there is some form of revitalization for that machine. Unfortunately I have not retained any software from that time, so that I cannot help you there. However, I would be very interested in hearing any information about the simulator you wrote. Is there / will there be a report on that project somewhere ? Could you send any description ? How do you simulate the console ? What do you do in hardware / in software ?? Interested in swapping ? I wrote a simulator for a Siemens S 2002, and I have a copy of the Algol compiler that went with that machine (no operating systems at that time, ca. 1960). The S2002 was a binary-coded-decimal 12 digit machine, the one I worked on had 10 K words of core and 10 K words of drum, and all of that is in the simulator. I have compiled and executed Algol programs on it - the simulation on a PC runs of course faster than the original hardware at that time; do you have some timing estimates for your simulator ? Very best regards John G. Zabolitzky