write  EEPROM_MAGIC_BYTE_1 to EEPROM_START_ADDRESS + 1, not EEPROM_START_ADDRESS
write  EEPROM_MAGIC_BYTE_1 to EEPROM_START_ADDRESS + 1, not EEPROM_START_ADDRESS

This way the code for remembering the last pattern will work.

Blinkinlabs/BlinkyTape_Arduino