How to flip TATE 180 degrees?

[felleg]

By following the steps described here (https://github.com/RetroPie/RetroPie-Setup/wiki/lr-mame2003#tate-mode), I managed to get TATE mode working (see picture below). This involved:

• using mame2003
• setting video_allow_rotate = "false" in /opt/retropie/configs/arcade/retroarch.cfg
• launching a game, select+X, and enable TATE mode.

My problem is that the orientation of the image would be more appropriate if flipped. As you can see, I have USB connections on the side where the bottom of the game image currently faces. Flipping the TATE mode 180 degrees would solve this, but how can this be done?

Thank you in advance.

Pi Model or other hardware: 3B
Power Supply used: (If using a Pi): Canakit 5V supply
RetroPie Version Used: 4.2, I think
Built From: Pre made SD Image on RetroPie website
USB Devices connected: A USB Key, a USB Keyboard, A Hori Pro FC controller
Controller used: A USB Keyboard
Error messages received: no error message
Log found in /dev/shm/runcommand.log (if relevant): no log
Guide used: n/a
File: n/a
Emulator: n/a
Attachment of config files: none

[markwkidd]

( @dankcushions is the expert on this topic )

[felleg]

bump, sorry