In the last two days, a potential client has requested something unusual. He asked if there is a way to include the PIC programmer INSIDE the product PCB. The idea is that he wants the PIC firmware to be update-able without any external hardware (such as a PIC programmer). I guess that he wants the PIC programmer to be "built-in" to the product, and accessible via a WinXP system. His reason is that the use of external programmers is error-prone for the final client. Of course the bootloader came to mind, but PICs don't have an internal bootloader, so the "bootloader code" have to be programmed in anyway; so his suggestion overrides the input. So I have brainstormed the idea, and have one possibility as follows: use the FT232R with pins arranged in bit-bang mode. Control the 12V VPP switch with the pins, connect PGD and PGC to two other pins, and create a chargepump with several .22uF ceramic caps & diodes driven by the 6M osc bit-bang output. It would be slow (relative to a standard PIC programmer) but simple and tidy. To program the device, just connect the FT232R to a host's USB port and drive the application with a WinXP application. The WinXP app needs to know only how to program only ONE device. Flames appreciated. Other ideas welcome. --Bob -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist