Background

Jim Drew has designed SX-64 Ultra Reset and has done great setup guide for his product (ultrareset.pdf).

When I noticed that there are no European providers for Commodore SX-64 reset functionality I decided to draw up my own custom pcb version and coded a new reset logic functionality with more customizable settings. And as there was no open source version available, so I've also decided to go with open source approach (link to gerbers are in the bottom of the page). [ebay link]

With supporting 4 kernals you can have for example optimized kernal function key shortcuts for pi1541 and sd2iec on different kernals. And with audio hint its easier to keep track of that action the button will trigger.

Usage of SX-64 Über Reset board

Usage is simple, by holding down normal reset button which is located next to colume contol, you can count the beeps (1000ms apart (*)) before releasing the button for invoking different actions. Releasing the button executes the action and then resets the computer (and plays reset beep if it has not been disabled).

beepsactionsignal connector on the pcb
0Reset drive
1Reset computerR
2Next active kernal numberJ2 and J (rolls back to 0 after 3)
3Toggle drive numberD (toggles 8 vs 9)
4Kernal number #1 (00) if J2 is unconnected only 1st bit(J) counts
5Kernal number #2 (01) if J2 is unconnected only 1st bit(J) counts
6Kernal number #3 or #1 (10) if J2 is unconnected only 1st bit(J) counts
7Kernal number #4 or #2 (11) if J2 is unconnected only 1st bit(J) counts
8Toggle reset beep ON/OFF LED (beep of 200ms)
9Toggle startup beeps ON/OFF LED (series of 50ms beeps)
10Toggle wait time between beeps1000ms vs 2000ms
11-*Toggle mute all soundsLast on the list so long press brings sounds back

Changed settings are stored in EEPROM so they survive power offs.
(*) Can be toggled to 2000ms with 10 beeps. Alternatively one could replace piezo beeper with resistor and a led if visual output is prefered over the audio.

Installation

PCB is a tight fit and can be screwed in place with original screw. See attached pic for example. You need to know how to use soldering iron as random color wires will need to be soldered in place.

Youtube demo video

Links to related resources:

Project gerber files:
* https://github.com/rainisto/pcb-gerbers/tree/main/sx64-reset
Project pic source code and pre-compiled hex:
* https://github.com/rainisto/C64-Kernal-Switcher/tree/SX-64/code
Rom Adapter (for kernal and 1541 roms) which can be used for example for 4 different kernals:
* https://github.com/SukkoPera/Open2327RomAdapter
Default SX-64 kernal images:
* http://www.zimmers.net/anonftp/pub/cbm/firmware/computers/c64/
JiffyDos SX-64 overlays can be bought here:
* https://restore-store.de/jiffydos/201-jiffydos-sx64-rom-overlay-image-set.html
* https://store.go4retro.com/jiffydos-sx64-rom-overlay-image-set/
JaffyDos 1.3 patcher can be downloaded from here:
* http://blog.worldofjani.com/?p=3544


C-2022 Jonni Rainisto