protect ArduinoISP from getting reprogrammed but still use it

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1

Hi,

I am using multiple Unos at a time, one as an ArduinoISP for programming ATTiny's and another for testing code on those Tiny's. I have already accidentally reprogrammed it a few times by forgetting to change the Port. Is there an easy way to prevent myself from accidentally reprogramming the ArduinoISP while still allowing it to function for uploading sketches to the Tiny's? I was thinking about changing the device ID so it wouldn't accept normal Uno sketches, or something with the Reset pin, but I dont know if that would make it cease to function as a programmer. Maybe I could remove the bootloader, and then upload the ArduinoISP sketch using another ArduinoISP...

thanks!

2

I use a 10uF capacitor between reset and Gnd on the Arduino used as ISP, which keeps me from wiping the Arduino as ISP sketch.

3

Will programming the 'programmer' via ICSP not work? It will wipe the boot loader so you can't upload via USB any more.