Dmitry Kiryashov writes: >So Step parameter mean points of time when RC7 parameter take next value, for >example above at start moment (time=1) RC7=0 , at time=5 RC7=1 , at time=7 >RC7=0 ,i.e. parameter Step means absolute value when pin take next value ? >Or maybe parameter Step mean relative value - i.e after start pin RC7=0 during >step=1 , RC7=1 during step=5 and so on ... >WBW Dmitry. >P.S. If someone have detailed documentation about internal format of stimulus >file please attach me it with reply letter . An update to MPLAB-SIM was posted on the Microchip BBS and should be on the web page as well (www.microchip.com). The file called README.LAB in this update has an expanded section on the stimulus files for the simulator and should answer all your questions. This update is a fix for the timers in the 17c4x family which were not functioning in the last release.