MIT
This page is designed to allow for a quick look over all the drivers with a MACHINE_IMPERFECT_TIMING flag by giving, as much as possible, an idea on the amount of effort needed to fix them.
acorn/aristmk5
Games are running at double speed.
alpha/alpha68k
goldmedl, goldmedla, goldmedlb - Dash events timers relies on MCU irq timings, which can't be accurate til the MCU is decapped and emulated.
alpha/alpha68k_n
sstingry - Super Stingray MCU irq controls timer speed. The MCU has been hooked up but the clock is almost certainly wrong.
bmc/popobear
Timer chip isn't emulated (controls auto-animation on title screen + something else during gameplay?).
cave/cv1k
Games are running faster than on real hardware.
chess/tasc
More accurate dynamic cpu clock divider is needed.
dataeast/progolf
MC6845 timings are wrong.
fidelity/eag68k
feagv10 - V10 CPU emulation is too slow, MAME 68040 opcode timing is same as 68030 but in reality it is much faster, same goes for V11 of course (see below).
feagv11 - V11 CPU should be M68EC060, not yet emulated. Now using M68EC040 in its place at twice the frequency due to lack of superscalar.
gaelco/blmbycar
watrball - Game speed should be checked against real hardware. It depends on a bit the emulation toggles.
handheld/hh_ht11xx
MCU frequency guessed.
hegenerglaser/modular
Waitstates emulation is preliminary.
konami/cobra
konami/konamigs
ddrkids - Songs desync.
konami/konamim2
Games are running slower than they should.
mephisto/mm2
mm4tk, mm5p - They need proper emulation of the TurboKit (it's not as simple as a CPU overclock plus ROM patch).
misc/monon_color
Clock divider unknown.
misc/sttechno
Needs real raw screen parameters and figuring out exactly how IRQ6 is supposed to actually work.
misc/xtom3d
pumpit1 - Flickers at start of any song without any feedback, abruptly throws steps with working playback, ends with silence and steps still going.
nichibutsu/clshroad
clshroad and clones - Main and sound CPUs synching isn't perfect.
nintendo/cothello
CPU speed is wrong, it's likely running at 1.79MHz. But that's way too fast compared to videos of the game. 0.9MHz(XTAL/4) is also too fast. It's probably due to the M58741P HOLD pin halting the 8080, which is not emulated.
saitek/risc2500
More accurate dynamic cpu clock divider is needed.
sega/sega_beena
Misses storyware layout.
sony/news_r4k
subsino/lastfght
Blitter timings are guessed.
taito/taitojc
Games are running at wrong speed(unthrottled?) compared to PCB recordings, easily noticeable on sidebs/sidebs2, for example the selection screens are too fast, and the driving is almost twice as slow.
taito/taitopjc
Analog inputs update at a slower rate (about every 8-10 frames instead of every frame).
tch/rltennis
Needs proper timing and interrupts (currently has extra hacky blitter int generation @ vblank).
tiger/bingobear
tvgames/spg2xx_shredmjr
Bad music timings (too slow).
vectorgraphic/vector4
CPU wait states, S-100 interrupts and ready aren't emulated.