08683: spec128: Main menu cursor doesn't work when "MGT DISCiPLE" device plugged

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
08683	Crash/Freeze	Major	Always	Jun 24, 2023, 17:42	Jun 29, 2023, 22:17

Tester	ArcadeShadow	View Status	Public	Platform	MAME (Official Binary)
Assigned To		Resolution	Open	OS	Windows 10/11 (64-bit)
Status [?]	Confirmed			Driver	sinclair/spec128.cpp
Version	0.255	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	08683: spec128: Main menu cursor doesn't work when "MGT DISCiPLE" device plugged
Description	Start the ZX Spectrum 128 system with the "MGT DISCiPLE" (spectrum_disciple) device plugged on the exp slot, then at the main menu, the cursors keys don't work. Tried also with the "MGT +D" device plugged, and it works.
Steps To Reproduce
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	spec128

Attached Files

No.21601 AJR Developer Jun 29, 2023, 22:17	There's a good explanation for this: the DISCiPLE device also adds two Interface II-type (i.e. keyboard-mapped) digital joysticks, and MAME maps the directional inputs for the first joystick to the cursor keys, so the system thinks two keys are being pressed at once. Nullifying the codes for "Kempston\Sinclair P1" in the input menus allows the cursor keys work normally.