Commodore Plus/4 and C-16 Compatibility

In this Compatibility Mode, using emulators, the keyboard work exactly as it was original conceived for Plus/4 or C-16, including all the symbols and legends of the keys.

This mode has to be selected when an emulator of a C-264 computer series is in use, to ensure full compatibility. Remember to use the downloaded .vkm files and set the keyboard emulation as Positional (User).

Press C= and CONTROL, to go back to PC Compatible Mode.

Commodore-64 and VIC-20 Keyboard Compatibility Mode

Plus/4 Keyboard in C-64 Mode
C-16 Keyboard in C-64 Mode

However the C-64 and the C-16 are physically similar, the position and function of some keys are different, like the cursor keys for example.

With the intention to make it intuitive, instead of keeping the original position of keys of a C-64 keyboard, I’ve changed the location of some keys keeping the original Plus/4 and C-16 layout as much as possible. 

Due to the fact 264 series computers add new keys, some of the C-64 keys had to be redefined as you can see in the diagram below (like the four cursor key for example). This way you don’t need to remember the real C-64’s location of every key. As you can see, location of – (minus), * (asterisk), + (add), = (equal), £ (pound) and CLEAR/HOME do not change.

The changes are:

  • ESC key works as RESTORE.
  • The four cursor keys works as labeled (yes, the .kvm files automatically press Shift if you want to move cursor Up or Left).
  • F1/F4, F2/F5, F3/F6 and HELP/F7 work as F1/F2, F3/F4, F5/F6 and F7/F8 respectively.

Remember to set your keyboard emulation in “Positional (User)” and choose the .vkm file corresponding to your emulator.

To exit the emulator, press C= and CONTROL keys to switch back to PC Compatible Mode.

Accesing Arrow keys (← and ↑) and Pi symbol.

If you want to use the Left Arrow Key or the Up Arrow Key, you need to hold RESTORE Key and press the Left or Up Cursor Key (do not confuse Cursor Keys with Arrow Keys, the former move the cursor and the latter draw an arrow in the screen). You can also use the Pi (π) symbol if you press Shift too.

Plus/4 Keyboard in C-64 Mode with Restore Key pressed
C-16 Keyboard in C-64 Mode with Restore key pressed