Hi Heinz, Thanks for the very useful information. Waterloo software as the SuperPET (in 6809 mode) - the document that I have describes the microWAT and SuperPET as separate hardware (which they obviously are!), but makes very little distinction once it gets into the software. This is probably how the microWAT and SuperPET are "the same" when the hardware is different ... It appears that WSL is used to make the same software run on both platforms. From the document I have: "SOFTWARE PORTABILITY When the 6809 was chosed as the microprocessor for the microWAT and SuperPET, we realized that microcomputers which incorporated other microprocessors such as the 68000, 8086, 8088 and Z8000 were about to be announced, and some were even available. It would, therefore, be unwise to prepare extensive software systems specifically for the 6809. The systems language WSL is ment to produce code which is portable. By using WSL to write the language interpreters, the editor, the library the assembler development system, and in fact the WSL compiler itself, it should be a relatively easy job to move or "port" the system to other machines and interface it with their operating systems." Can you provide more information - at some point I, if I can gather enough material together, I would like to try and get the thing to run - do I need to provide this "key"? Also, can you shed any light on the 1/2 height completely potted (ie: sealed from tampering) card that I found wrapped up inside the system? (See previous posting for complete description). Any other information/resources you can point me at would be greatly appreciated. Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.parse.com/~ddunfield/museum/index.html