Reset Display Mod

Nothing beats the thrill of modding a mod!! The Switchless Reset Mod (link), in which an Arduino Pro Mini is used to do Warm or Cold Resets (Soft and Hard Resets), needed a little upgrade… Instead of just resetting the C64, I wanted to keep track of how many Warm and Cold Resets I had done since the last power-on and it should (of course) be shown on a nice blue LCD display. Why you may ask? Well, because it’s cheap (4$ including shipping from China), it’s blue and I had no better things to do with it…

I ordered a so-called 16×2 I2C serial LCD display (16 characters and 2 lines). The LCD has a small black interface board attached to the back. This small circuit allows to interface with the Arduino using just 2 wires (+ 2 wires for Ground and +5V). Without the small PCB, a whole bunch of wires have to be connected to the Arduino. There is also a small potentiometer on the black interface board for adjusting the contrast of the display.

I used the instructions on how to use the display here (link) and added my own display code to the original code for the Switchless Reset Mod (link). It’s important to exchange the standard LiquidCrystal library with the one found here (link) – otherwise it won’t work!  The final source code can be found at the end of this post.

The display was connected to the Arduino Pro Mini using these four pins: VCC (Vcc line), GND (GND line), SDA (analog A4 pin) and SCL (analog A5 pin). I tested it in my ZIF socket modded Commodore 64C (link).When the Commodore 64 is turned on, this is what is written on the display. Pressing the RESTORE button for less than 2 seconds will tell the user to press longer! Pressing the RESTORE button for 2-4 seconds, the system will do a Warm Reset.

Pressing the RESTORE button for 4-10 seconds, the machine will do a Cold Reset. If the RESTORE button is pressed for more than 10 seconds,will let the user know to let go of the RESTORE key a little faster. After any reset the total number of Cold and Warm Resets, since the last power-on, is displayed.

A little video showing the mod in action.

Here is the source code for the Reset Display Mod. Double click to enable plain text view of the code. Changing the text written on the display should be pretty straight forward 🙂 Please use it at your own risk!


© 2016

1 comment on “Reset Display Mod

  1. Code updated: To keep the Arduino from constantly driving the Reset line, the pinmode has been changed to INPUT by default. Whenever the Arduino is requested to pull the Reset line to LOW (for Warm or Cold resets), the pinmode is changed to OUTPUT. After the reset, the pinmode is set back to INPUT again.

Please leave a comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.