The Bubblegum Chip, Now With Steroids! The Atmel ATTINY85 is a great chip (cheap, easy to use, supported in the Arduino IDE). Unfortunately it only has 5
Arduino Slovakia - ATtiny85
High-Voltage Serial Programmer - Rescue AVR Chips
ATtiny85 Powered High Voltage AVR Programmer
attiny85 DIY Programmer – and thus goes by another day
Flash Trigger Device Using the ATtiny85 – Ted Myers
Technoblogy - ATtiny Low Power
Attiny85 – Arduino, ESP8266, ESP32 & Raspberry Pi stuff
ATtiny85 BOOST CONVERTER
Arduino-based AVR High Voltage Programmer
Flash Delay Circuit
ATTINY Fuse Repair Programmer/Fuse Doctor V2.1 from microprogrammers on Tindie
ATtiny85 Arduino Board: How to Flash the Arduino Bootloader and Run A Simple Sketch — Maker Portal
DIY Electronics & Photography - Tyler's Invention Blog