(DIY) AMIGA 500 - SWITCHLESS BOOT DRIVE SELECTOR Rev.3

(RETRO VERSION of 3 RESET BOOT DRIVE SELECTOR)

Hello,

This circuit board has been tested on the Amiga 500 and works perfectly.

"A500 - Switchless Booter" is a circuit that allows you to change the boot priority of the Amiga 500's floppy drives by 3 consecutive Resets. (3 times pressing CTRL + left AMIGA + right AMIGA keys changes DF:1 to DF:0)

If you use a second floppy drive connected to your A500, like GOTEK Drive or a mechanical floppy drive, (as DF:1), then you need a boot selector to boot from the second drive. (Most boot selectors work with a toggle switch, but not this one)

While using "3 RESET BOOT DRIVE SELECTOR", if you want to toggle your floppy drives (DF:0 <> DF:1) you just need to press Reset keys 3 times. (Reset Keys are: CTRL and the two Amiga keys together)

Benefits of Switchless Boot Drive selector:

1) This "A500 - Switchless Booter" protects your Amiga 500. If you change the mechanical switch position while transfering data from floppy drive, this may cause damage to 8520 (Even CIA) or 5719 (GARY). Switchless booter do not let this happen.

2) Most users need to make a hole on their Amiga 500 for attaching boot selectors mechanical switch. This "A500 - Switchless Booter" toggles drives electronically, there is no mechanical switch, so you do not need to make a hole on your your Amiga.

Special thanks to Onur Sapci for his contributions to this project.

COMPONENTS:

2 Pcs. 74LS74 DIP14 ( Do Not Use HC or HCT ! )

74LS12 DIP14

74LS126 DIP14 ( Do Not Use HC or HCT ! )

2 Pcs. BC 237 TO-92 TRANSISTOR

2PCS. 20 PIN ROUND MALE HEADER (Get a 40 pin and cut it)

DIP 40 IC SOCKET

4 Pcs. DIP 14 IC SOCKET

2 Pcs. 1N4148 DIODE

100nF CAPACITOR (More than 10 Volts is OK.)

10 MICROFARAD 25VOLT Electrolytic Capacitor (More than 10 Volts is OK.)

47 MICROFARAD 16VOLT Electrolytic Capacitor (More than 10 Volts is OK.)

4 Pcs. 4.7 K 1/4 WATT RESISTOR

10 K 1/4 WATT RESISTOR

47 K 1/4 WATT RESISTOR

68 K 1/4 WATT RESISTOR

The other version (programmable version) of this project is here:

https://www.pcbway.com/project/shareproject/AMIGA_500___SWITCHLESS_BOOT_SELECTOR__3_RESET_BOOT_DRIVE_SELECTOR_.html

If you have a programmer capable of testing IC chips, such as the 74LS series, you should remember to test them before soldering. Some chips may be defective. (TL866 Minipro Programmer can test some logic ICs)

In order to protect your electronical devices, always turn off your Amiga before connecting or disconnecting the cables or any other device.

Gerber files and component list are subject to change without notice. Before paying for the PCBs, be sure to update your orders!

Use this PCB at your own risk !

Have fun

Thank you.