Arduino Unoを
Arduino Unoと
素の
https://github.com/MCUdude/MicroCore
IDEでFile->Examples->11 Arduino ISPをTools->ProgrammerをArduino ISPにTools->BoardをATtiny13に
データシートで
Arduino ISPの

コンデンサーは
https://create.arduino.cc/projecthub/arjun/programming-attiny85-with-arduino-uno-afb829
なくても
Pin0は
void setup() {
// put your setup code here, to run once:
pinMode(0, OUTPUT);
}
void loop() {
// put your main code here, to run repeatedly:
digitalWrite(0, HIGH);
delay(500);
digitalWrite(0, LOW);
delay(500);
}