Amiga 500 DF selector
This card allows to automatically exchange the boot between internal floppy and an external floppy. You need to reset the Amiga twice within 2 seconds to switch from internal / external df0 mode. The state of the switch will be maintained even when the machine is turned off.
Components: U1 ATTINY25 (SOIC8) U2 CD4066 (SOP14) U4 SOCKET 40 PIN (DIP40) TULIP R1,R2 10Kohm (0805) R3 560ohm (0805 OPTIONAL) C1,C2 100nF (0805) J3,J4 HEADER MALE-MALE TURNED
Directory Gerber : File for make the PCB IMG : Tester's pictures Firmware : Firmware for Attiny25 (you can use avr commands like Arduino's IDE or an AVR programmer to write the HEX file) Fuse (Extend: FF . High: DF . LOW: 52)
How it works Use Ctrl-Alt-Amiga to switch between df0 internal/external. You need to do two resets within two seconds to change modes The buzer emits a beep in normal mode, two beeps in inverted mode Compatible with Amiga 500,1000,2000
How to burn the firmware You can use avrdude integrated on arduino via command line, or simply download a gui (if you use windows) like AVRDUDESS. I use Atmel ICE with Microchip Studio.