So my post that I'd typed out just got lost when I tried to submit. So I'll post the short version.
Normally this board is programmed with a straight parallel cable to the pcb with no extra hardware. I'm trying to switch to use a USB programmer. USBASP and TinyAVRprogrammer have both not worked with either avrdude or loading a bootloader in the Arduino IDE. Mostly I get an invalid chip signature error, but don't see any reason I should be getting that aside from something to do with adding an external crystal.
On the schematic all pins are direct connections to the chip but pin6. It has some extra connections on the way to the Reset Pin of the chip. Could someone look at that and see if that may be what's causing things to fail when I'm using the USB programmers? I want to see if it's a board layout issue making it impossible before I dig much deeper into the process.
Thanks for any help.