This is a electronic-switchable (mechanical-switchless) df0 df1 boot changer for Amiga 500

3 sequential resets from keyboard (ctrl + left amiga + right amiga) will switch drives df0 <> df1

to switch the drives; you should reset when boot screen (blue disc) appears on the screen for three times. If you wait more than 30 seconds after a reset, counter wil be cleared.

This circuit counts resets with a pic16f628 and change position of CIA2 (8520) legs 13 and 14 with 74HC4066

.HEX file should be programmed into PIC16F628A









