User Interface

You navigate the OLED interface by pressing the A and B buttons.

  • The A button is for ‘Action’, i.e. change an option or execute something
  • The B button moves ot the next screen.

The OLED has a screen-saver that will turn off the display after 5 minutes. Press the B button to wake it up.

JVS communications to your cabinet has to be operational for the user interface to be enabled.

Status Screen (default)

This screen gives you basic status of the running setup:

  • JVS Status and found IO board
  • User Lock is enabled
  • Status of SyncGuard, or HDMI->Monitor if you’re using a flat panel with HDMI directly from the DE10
  • JVS update frequency

Input Test

This screen will show what the JVS IO board is telling the expander, and is a convenient way to troubleshoot either your JVS cabinet or if you suspect something is up with your MiSTer installation. Active inputs will be highlighted in real-time.

SE=service button, C1/C2=coin1 coin2, TS=test button

Video Input

Shows number of lines, horizontal and vertical frequency of the video signal coming from MiSTer. If you use digital video straight from the DE10, this screen say that RGB DAC is disabled.


This is where you configure SyncGuard to match your monitor. The default is Tri-Sync. Options are:

  • 15kHz/JAMMA
  • 15/25 Auto
  • 25 kHz/EGA
  • 31 kHz/VGA
  • Tri-Sync
  • Off

USB mode

Selects if the Expander operates in MAM Keyboard or 2xGAMEPAD mode.

Keypress (Space).

Only available when in Gamepad mode, press B button to issue the ‘Space’ key to MiSTer.

Keypress (Enter)

Only available when in Gamepad mode, press B button to issue the ‘Enter’ key to MiSTer.

MiSTer menu

Default is ‘All Options’ which lets you control MiSTer volume and settings by using joystick and buttons on your cabinet. If you only want to enable core selection, change it to ‘Core only’.

Save Config

This will save the configuration to internal EEPROM. If you long-press A, configuration will reset to factory default and the Expander will reboot.


Displays various voltages:

  • JVS 5V – what the Expander is getting from your cabinet
  • USB VBUS – the voltage supplied to the Expander from the DE10 via the USB OTG cable
  • USB HUB – Voltage supplied to USB devices
  • Int 3.3V – Internal 3.3V supply.


Shows Expander serial number, PCB revision, number of times config EEPROM has been written to and current firmware version.

Last Updated on 2022-12-20 by admin