This question is probably best answered by the Microchip guys, or Walt Banks, but here goes. I'm trying to execute MPASM from another DOS program using the int 21h 0x04B function ("Load or Execute a Program"). I have trouble sending command line parameters to MPASM. I have tried putting in the string from the command line part of the Parameter Block (which works fine for Edit, MPSIM) as well as forcing it into the FCB block, but in both cases, it doesn't work - a "random" ASCII character is put in with .asm (ie "3.asm") according to MPASM. I do have enough space to load MPASM (usually around 500K in the Windows/95 DOS box). Does anybody have any ideas? Thanx and I hope everybody has a wonderful New Year! myke "There are only three kinds of economists in the world. Those who can count and those who can't." - Eddy George, governor of the Bank of England