Hi Steve,

Code space is not an issue. I cannot use the hw uart as I need it to generate rs485 at 250Kbaud ! On the PCBs it is wired as TX only, but even so I have not seen a half-duplex bootloader (please correct me, anyone..)

I looked at TinyBootloader earlier, but again it is tied to HW UART pins.

I'll keep looking. I found a mention on the Spark Fun site that bloader 1.6 could handle the 16f819, which doesn't have a uart. Maybe a bit iof creative code work is required...

bill