At 06:38 PM 11/17/02 +0000, you wrote: >It is a quad 2 input NAND gate and in the 74 TTL series will be 7400 >(7403 is open collector). In CMOS series 4012 Given the component values, it had better be a 74HC00 or similar. TTL won't work. 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 -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu