following this message from Sonic32
http://www.supermodel3.com/Forum/viewtopic.php?f=3&t=1919&start=30#p18219
I'm trying to emulate the sega billboard
it is a lamp ramp + 2 digits display for each players
Few informations are displayed, so the interrest is really limited but it's a part a of the emulation
The digits are drived by the the cpu/rom to allow display (not only 0-9 a-f digits as usual). Each segments of the digits can be switch on/off by the rom prg which allows to produce animations.
You can find a lots of informations here
https://www.arcade-projects.com/threads/vs-billboard-output-from-sega-st-v-model-2-model-3-naomi.1142/
The rom is emulated and the datas are sent (raw digits + lamp state) to Supermodel Outputs.
These outputs are processed by my own little software (the same I use to get the mame/Supermodel outputs) and sent to an arduino.
The arduino processes the raw datas and sends them to a 8*7 segments digits
Complicated isn't it ?

I'm managing to make a little video (hard to handle camera and play in the same time

P2 digits are on the left, P1 digits are on the right
P2 P1 lamps are simulated by an '8' at digit n°4 and 5 (I was to lazy to connect a real led)
https://mega.nz/embed/Z8hQkQLZ#OH12uhBlw-AFulOIaQhhEtt7c-14cHqlnPYOgP60flg
only 4 games support Sega Billboard (with their different revisions)
Virtual-On Oratorio
Fighting Vipers 2
Virtua Fighter 3
Virtua Striker 2 (goal is displayed when you make a goal)
Sometimes, some characters stay on the display, or lamp continue to blink