This schematic of the Stack Light Rifle for the VIC20/C64 is drawn using the program Accel (which (in 2017) is a 20 year old CAD system).
I've drawn this schematic in order to repair a non-working SLR. Feel free to use it to build replacement
circuit boards for the SLR, however I would suggest that the circuit isn't the best lightgun circuit around.

For those who can't open the .SCH file, there is a .PDF of the schematic that holds the same info.

Jan Derogee (2017)