On the TI-85, an interrupt is triggered every 200th of a second, and when ON is pressed. When a TSR is installed, is it called when the ON key is pressed as well as the interrupts occurring 200 times per second? I my TSR to "see" the ON key being pressed before the TI-OS sees it. Is this possible? ________________ Jeff Tyrrill http://tyrrill-ticalc.home.ml.org/ http://ti-files.home.ml.org/