Macintosh II (macii) shows erratic mouse pointer movement in recent MAME versions.

MAME version

0.264

System information

GNU/Linux (Debian 12, Lubuntu 22.04), Windows 11. Graphics: Intel XE, AMDGPU.

INI configuration details

#
# CORE CONFIGURATION OPTIONS
#
readconfig                1
writeconfig               0

#
# CORE SEARCH PATH OPTIONS
#
homepath                  .
rompath                   roms
hashpath                  hash
samplepath                samples
artpath                   artwork
ctrlrpath                 ctrlr
inipath                   $HOME/.mame;.;ini
fontpath                  .
cheatpath                 cheat
crosshairpath             crosshair
pluginspath               plugins
languagepath              language
swpath                    software

#
# CORE OUTPUT DIRECTORY OPTIONS
#
cfg_directory             cfg
nvram_directory           nvram
input_directory           inp
state_directory           sta
snapshot_directory        snap
diff_directory            diff
comment_directory         comments
share_directory           share

#
# CORE STATE/PLAYBACK OPTIONS
#
state                     
autosave                  0
rewind                    0
rewind_capacity           100
playback                  
record                    
exit_after_playback       0
mngwrite                  
aviwrite                  
wavwrite                  
snapname                  %g/%i
snapsize                  auto
snapview                  auto
snapbilinear              1
statename                 %g
burnin                    0

#
# CORE PERFORMANCE OPTIONS
#
autoframeskip             0
frameskip                 0
seconds_to_run            0
throttle                  1
sleep                     1
speed                     1.0
refreshspeed              0
lowlatency                0

#
# CORE RENDER OPTIONS
#
keepaspect                1
unevenstretch             1
unevenstretchx            0
unevenstretchy            0
autostretchxy             0
intoverscan               0
intscalex                 0
intscaley                 0

#
# CORE ROTATION OPTIONS
#
rotate                    1
ror                       0
rol                       0
autoror                   0
autorol                   0
flipx                     0
flipy                     0

#
# CORE ARTWORK OPTIONS
#
artwork_crop              0
fallback_artwork          
override_artwork          

#
# CORE SCREEN OPTIONS
#
brightness                1.0
contrast                  1.0
gamma                     1.0
pause_brightness          0.65
effect                    none

#
# CORE VECTOR OPTIONS
#
beam_width_min            1.0
beam_width_max            1.0
beam_dot_size             1.0
beam_intensity_weight     0
flicker                   0

#
# CORE SOUND OPTIONS
#
samplerate                48000
samples                   1
volume                    0
compressor                1
speaker_report            0

#
# CORE INPUT OPTIONS
#
coin_lockout              1
ctrlr                     
mouse                     0
joystick                  1
lightgun                  0
multikeyboard             0
multimouse                0
steadykey                 0
ui_active                 0
offscreen_reload          0
joystick_map              auto
joystick_deadzone         0.15
joystick_saturation       0.85
joystick_threshold        0.3
natural                   0
joystick_contradictory    0
coin_impulse              0

#
# CORE INPUT AUTOMATIC ENABLE OPTIONS
#
paddle_device             keyboard
adstick_device            keyboard
pedal_device              keyboard
dial_device               keyboard
trackball_device          keyboard
lightgun_device           keyboard
positional_device         keyboard
mouse_device              mouse

#
# CORE DEBUGGING OPTIONS
#
verbose                   0
log                       0
oslog                     0
debug                     0
update_in_pause           0
debugscript               
debuglog                  0

#
# CORE COMM OPTIONS
#
comm_localhost            0.0.0.0
comm_localport            15112
comm_remotehost           127.0.0.1
comm_remoteport           15112
comm_framesync            0

#
# CORE MISC OPTIONS
#
drc                       1
drc_use_c                 0
drc_log_uml               0
drc_log_native            0
bios                      
cheat                     0
skip_gameinfo             0
uifont                    default
ui                        cabinet
ramsize                   
confirm_quit              0
ui_mouse                  1
language                  
nvram_save                1

#
# SCRIPTING OPTIONS
#
autoboot_command          
autoboot_delay            0
autoboot_script           
console                   0
plugins                   1
plugin                    
noplugin                  

#
# HTTP SERVER OPTIONS
#
http                      0
http_port                 8080
http_root                 web

#
# OSD INPUT MAPPING OPTIONS
#
uimodekey                 auto
controller_map            none
background_input          0

#
# OSD FONT OPTIONS
#
uifontprovider            auto

#
# OSD OUTPUT OPTIONS
#
output                    auto

#
# OSD INPUT OPTIONS
#
keyboardprovider          auto
mouseprovider             auto
lightgunprovider          auto
joystickprovider          auto

#
# OSD DEBUGGING OPTIONS
#
debugger                  auto
debugger_port             23946
debugger_font             auto
debugger_font_size        0
watchdog                  0

#
# OSD PERFORMANCE OPTIONS
#
numprocessors             auto
bench                     0

#
# OSD VIDEO OPTIONS
#
video                     auto
numscreens                1
window                    0
maximize                  1
waitvsync                 1
syncrefresh               0
monitorprovider           auto

#
# OSD PER-WINDOW VIDEO OPTIONS
#
screen                    auto
aspect                    auto
resolution                auto
view                      auto
screen0                   auto
aspect0                   auto
resolution0               auto
view0                     auto
screen1                   auto
aspect1                   auto
resolution1               auto
view1                     auto
screen2                   auto
aspect2                   auto
resolution2               auto
view2                     auto
screen3                   auto
aspect3                   auto
resolution3               auto
view3                     auto

#
# OSD FULL SCREEN OPTIONS
#
switchres                 0

#
# OSD ACCELERATED VIDEO OPTIONS
#
filter                    1
prescale                  1

#
# OpenGL-SPECIFIC OPTIONS
#
gl_forcepow2texture       0
gl_notexturerect          0
gl_vbo                    1
gl_pbo                    1
gl_glsl                   0
gl_glsl_filter            1
glsl_shader_mame0         none
glsl_shader_mame1         none
glsl_shader_mame2         none
glsl_shader_mame3         none
glsl_shader_mame4         none
glsl_shader_mame5         none
glsl_shader_mame6         none
glsl_shader_mame7         none
glsl_shader_mame8         none
glsl_shader_mame9         none
glsl_shader_screen0       none
glsl_shader_screen1       none
glsl_shader_screen2       none
glsl_shader_screen3       none
glsl_shader_screen4       none
glsl_shader_screen5       none
glsl_shader_screen6       none
glsl_shader_screen7       none
glsl_shader_screen8       none
glsl_shader_screen9       none

#
# OSD SOUND OPTIONS
#
sound                     auto
audio_latency             2

#
# PORTAUDIO OPTIONS
#
pa_api                    none
pa_device                 none
pa_latency                0

#
# OSD MIDI OPTIONS
#
midiprovider              auto

#
# OSD EMULATED NETWORKING OPTIONS
#
networkprovider           auto

#
# BGFX POST-PROCESSING OPTIONS
#
bgfx_path                 bgfx
bgfx_backend              auto
bgfx_debug                0
bgfx_screen_chains        
bgfx_shadow_mask          slot-mask.png
bgfx_lut                  lut-default.png
bgfx_avi_name             auto

#
# SDL PERFORMANCE OPTIONS
#
sdlvideofps               0

#
# SDL VIDEO OPTIONS
#
centerh                   1
centerv                   1
scalemode                 none

#
# SDL FULL SCREEN OPTIONS
#
useallheads               0
attach_window             

#
# SDL KEYBOARD MAPPING
#
keymap                    0
keymap_file               keymap.dat

#
# SDL JOYSTICK MAPPING
#
sixaxis                   0

#
# SDL LIGHTGUN MAPPING
#
lightgun_index1           auto
lightgun_index2           auto
lightgun_index3           auto
lightgun_index4           auto
lightgun_index5           auto
lightgun_index6           auto
lightgun_index7           auto
lightgun_index8           auto

#
# SDL LOW-LEVEL DRIVER OPTIONS
#
videodriver               auto
renderdriver              auto
audiodriver               auto
gl_lib                    auto

#
# FRONTEND COMMAND OPTIONS
#
dtd                       1

Emulated system/software

Macintosh II (macii), Macintosh II Ci (maciici)

Incorrect behaviour

Mouse pointer moves erratically: it warps, goes back to previous positions, etc.

This only affects some Macintosh computers: -Mac II (macii) and Mac II Ci (maciici) seem affected. -Mac LC III is not so affected, but cursor movement is still quite imprecise. -Mac 128/512/Classic/SE are not affected: cursor movement is perfect.

MAME 0.263 was affected too, but MAME 0.242 was not affected, so it looks like a regression.

Expected behaviour

Mouse pointer movement should be correct: smooth and precise, as it is on real hardware.

Steps to reproduce

These are example commandlines to reproduce the problem in MAME 0.264

mame macii -ramsize 8M -hard1 mac711.chd mame maciici -ramsize 8M -hard1 mac711.chd

Additional details

It's not related to host OS: different versions of GNU/Linux, Windows 11, and different versions of SDL2 (latest stable also tested) all show the exact same problem, and the same absence of the problem with MAME 0.242

mamedev / mame