At 10:31 PM 11/28/2005 -0500, you wrote: I'm not that familiar with CCS C (except to know that it is not very much like the C language from doing a translation), but you should also consider inserting a delay between where you set PS2_CLK_OUT high and set it low or the strobe duration may not be long enough to work, depending on the efficiency of code the compiler emits. Worst (or best) case it could emit two succeeding bsf/bcf instructions that might not even reach the correct logic levels with a 20MHz clock, let alone be long enough to meet the requirements of whatever is connected to your interface. Data setup and hold times (probably more the former) could also be an issue, so look at that too. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com ->> Inexpensive test equipment & parts http://search.ebay.com/_W0QQsassZspeff -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist