>> Are all the lights on? They could still be too fast to see. With a >> 4 MHz crystal it would count at 1MHz; prescaled by 256 is 3.9 KHz, and >> counting to 256 the topmost light still blinks at 15 Hz. >> >> If I know what I'm talking about--I haven't done any PIC stuff yet, just >> reading. >Thanks for your help >I wasn't very clear. ports b and a aren't used yet, i just left them in there for the future. I calculated that if the timr counts at even 4 mhz, (.250 microseconds), this scaled by 256 should be about 64 microseconds. >Jeff You're right, I didn't include the timer itself counting to 256, so it should be slow enough. I don't think you've mentioned what you see, but I'll guess all the lights are off. You said you'd tried a simple program first, that made the lights on portc flash. If you didn't use that code to start writing this program then maybe you should take a copy of your code and just get it to flash the lights first. Then add the timer stuff back in. Barry -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu