In article <[log in to unmask] .com>, "Stigers, Gregory - ANDOVER" <[log in to unmask]> writes >Time for some fun. We got: > >> :RUN E017910.EXEC01 >> NEW SYSTEM DATE IS: 06/06/97 >> **** INTERNAL TRAP >> Instruction Memory Protection Trap >> [VSM] Undecoded status.info = -37 >> ABORT: E017910.EXEC01.N01 > I got something similar when I moved all 'X' in a subprogram, to an area defined in Linkage as X(2048). However, the calling program thought it was giving access to an X(256) area (what is passed is really just the start address); 2048 ran off the end of the data stack, and it barfed instantly, with a Protection error. However, if 2048 hadn't run off the end, it would have barfed later, in a much more subtle way. Point is, there was nothing to see, in the code of either program taken separately. You needed a model of the stack in your head to detect it by inspection. Have you got this sort of problem? -- Roy Brown Phone : (01684) 291710 Fax : (01684) 291712 Affirm Ltd Email : [log in to unmask] The Great Barn, Mill St 'Have nothing on your systems that you do not TEWKESBURY GL20 5SB (UK) know to be useful, or believe to be beautiful.'