I need to calculate a constant at compile time to set a delay. I have an equate: NumAve equ 0x40 ;Average 64 Readings that I set for the number of A/D readings I want to average. I want to average that number over one cycle of the AC power or 1/60 seconds. I want to call a Macro (You know it well Andy!) with the amount of the delay between A/D readings. The equation for the delay is: 1000000/60/NumAve-80 1000000 is me instruction rate 60 is the power line freq. NumAve (see above) 80 is my A/D overhead I want to invoke Andrew Warren's WAIT macro with the result. Any hints how to setup the expression?? Thank you, - -Mark _________________________________________________________ DO YOU YAHOO!? Get your free @yahoo.com address at http://mail.yahoo.com