There are a couple I know of. First there is ucsim which can be run on its own or as part of sdcc the free C compiler. Unfortunately it is command line based and not very easy to use. There is a DOS version too with a text based GUI that runs fine under Linux with dosbox but I still cannot get it to disassemble properly. Second there is 8051sim which can be downloaded from http://www.geocities.com/Yosemite/...tware.html but I have not yet been able to get it to compile which may be just because it is about six years old. There may be others but I have not done an exhuastive search. There are plenty of free or cut down MS windows based simulators, some of which run fine under wine. jsim51 seems to work OK although the colour scheme is a bit odd. You can find it at http://home.t-online.de/home/Jens...jsim-e.htm

I have also run Phyton's PDS52 under wine with just one problem which is easy to work around.

If you find a good GUI Linux 8051 simulator let me know.

Ian