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Commodore 64

Commodore 64 Ultimate (C64U)

Controls & basic settings

Multi Function Switch

It is a rocker switch that can be pressed or held upward or downward:

Action Operation
Switch on (when off) Press either upward or downward
Switch off (when on) Hold downward for 4 seconds
Reset (when not in menu) Hold upward for 1 second, then release
Toggle C64U Menu Press upward

C64U Menu navigation

The C64U Menu is accessible at all times. Pressing the Multi Function Switch upward pauses the running program and displays the menu; when you exit, the program resumes.

Key Function
W / S Move the selection up / down
D Open the selected sub-menu
A Return to the parent menu
RETURN Select an option or action
RUN/STOP Exit a pop-up, return to the parent menu or exit the menu (press repeatedly to exit quickly)
F1 Open the Tool Menu
F3 / F5 Page up / down
F7 Help
Y / N Confirm / skip saving changes on exit

The C64 cursor keys can also be used to navigate.

Safe Mode

If you change a setting that is incompatible with your display and lose access to the menu, you can boot in safe mode, which temporarily resets all settings to their defaults:

  1. Hold the Multi Function Switch downward for 4 seconds to switch off.
  2. Press and hold the RESTORE key.
  3. Switch on by pressing the Multi Function Switch upward.

To save the restored settings to flash, make any change, exit the menu and save when prompted.

Video mode (PAL vs. NTSC)

Temporary video mode selection at power on, by holding these keys:

Mode Keys
NTSC C= + N
PAL C= + P

To change the video mode and save it: C64U Menu → Video Setup → System Mode (RETURN) → choose PAL or NTSC → RUN/STOP to apply → Y to save.

Basic menu settings

Setting Path in the C64U Menu
HDMI Scan Lines Video Setup → HDMI Scan Lines → Enabled / Disabled
Built-in speaker Audio Setup → Speaker Mixer → Speaker Enable → Enabled / Disabled
RAM Expansion Unit (REU) Memory & ROMs → RAM Expansion Unit → Enabled / Disabled
Joystick swap Joystick & Controllers → Joystick Input → Normal / Swapped

In general, you must exit the menu to apply the setting and then press Y to save it.

Troubleshooting software

Some features (PAL/NTSC mode, REU, etc.) can cause certain programs to misbehave. Things to try:

  • Change the video mode from PAL to NTSC, or vice versa.
  • Disable the RAM Expansion Unit.
  • If you have installed the JiffyDOS ROMs, switch back to the stock C64 ROMs.
  • Disconnect unused IEC peripherals (e.g. external disk drives).
  • Disable the virtual disk drive B: Disk Drive B Options → Drive = Disabled.
  • Disable Software IEC: Tool Menu (F1) → Software IEC → Turn Off (if available).
  • Disable printer emulation: Tool Menu (F1) → Printer → Turn Off (if available).

Typing commands

When you switch on the C64U (without a cartridge) the READY. prompt appears with a blinking cursor, ready to receive commands:

  • Letters appear in uppercase by default; you don't need SHIFT to type an uppercase letter.
  • To type the double-quote mark ("), hold SHIFT and press 2.
  • To delete a character, press INST DEL.
  • Press RETURN (with the cursor anywhere on the line) to run the command.

If you get into a confusing state while typing commands, hold RUN/STOP and press RESTORE: the screen clears and a new READY. prompt appears.