Hi there I am using the BSF instruction to set bits on PORTD on a 16c74A. The whole port is configured as output (CLRF TRISD). The problem is, when I set a bit on the port, any other bits that were set, clear and then the bit the instruction specifies, sets. Why don't the other bits remain set? I also had a problem getting the serial port on the 16c74A to work. I tried everything! It turned out the 2.4576MHz crystal was not quite accurate enough. One would think that crystals were supposed to be quite accurate. Great list! Gavin vulcan@ihug.co.nz - - - - - - - - - - - - - -