Other things On this page.... H-Bridge chips, WISP628 programmer H-Bridge chips Chip Manufacturer Max. current Voltage range Internal clamping diodes Number of channels Price at Digikey L293D SGS-THOMSON 600mA 4.5 - 36 yes 2 $2.78 L293 Texas Instruments 1A   no 2 $2.78 L298 SGS-THOMSON 4A no 2 $5.47 SN754410 Texas Instruments 1A 4.5 - 36 yes 4 $2.45 LMD18200 National 3A 12 - 55 yes 1 $15.26 WISP628 In-circuit PIC Programmer click to enlarge This is an in-circuit PIC programmer design which uses the PC serial port to do it's magic. It takes power from the PIC circuit being programmed, and it has a voltage boost circuit so that you don't need to feed 13.5 volts to the PIC in order to program it. The design here is practically identical to the wisp628 design found here: http://www.voti.nl/wisp628/ The only changes were the addition of a voltage regulator in case external power is supplied to the programmer and the addition of an LED which gives a status signal to the user. For those that missed the group purchase, bare boards and complete kits can be purchased from the original designer. See the following link: http://www.voti.nl/shop/order.html#K-Wisp628 click to enlarge Parts list IC1 PIC16F628 IC2 MAX232 IC3 7805L C1,C2 18pF C3,C13,C4,C5,C6,C7,C8,C9,C12 1uF C10,C11 22uF D1,D2,D3 1N4148 Q1 20M Q2 2N3904 R1,R2,R3,R4,R6,R8 47R R6,R7 1k JP1 2X07 pinhead JP2 1X02 pinhead X1 9pin Serial connector Assembly notes There are a few things that can't be determined from the photograph. The diodes are placed with the black bands up. C3 and C13 get mounted under the IC sockets. They can be mounted on the bottom of the board instead if you find the sockets get in the way software to run the programmer Wisp (DOS) XWisp (DOS - Python required) WinWisp (Python required) Bumblebee (Java required)