Firebeat BMIII turntable teleports (digital and analog modes)

[SneakySnake04]

MAME version

mame-windows-gcc-41f531db658388ac82b21f7bcf300aad6c7a460e

System information

Windows 11, 64bit, version 23h2, JP Locale, EN language, Radeon 6800, i9-9900k, opengl, using a Phoenixwan (old model) through DirectInput

INI configuration details

No response

Emulated system/software

Konami Firebeat

Incorrect behaviour

The turntable on Firebeat games teleports on both digital and analog. I don't know why, it just does. Linear from 0-15, then teleports back to 0, then teleports to 50, then linear from 50-100, then teleports back to 50, then teleports again, it just keeps teleporting.

mame_5EOkVVkxX6.mp4

Expected behaviour

Turntable should be linear from 0-100, and loop around (like a knob)

Steps to reproduce

1. Boot MAME
2. Open Beatmania III
3. Move the turntable (digital or analog is fine, the problem persists on both)

Additional details

No response

[987123879113]

Something weird going on with the way MAME is handling values above 0xff here. I changed the range to 0-255.