This page is designed to allow for a quick look over all the drivers with a MACHINE_NOT_WORKING flag by giving, as much as possible, an idea on the amount of effort needed to fix them.

20pacgal

25pacman - Newer set on slightly different hardware.

2mindril

Missing working simulation of the sensors. Requires a major rework of the artwork sub-system.

39in1

19in1, 48in1 and clones, 60in1, fruitwld and clone, jumanji, plutus, pokrwild, rodent - Should be correctly decrypted but expect something different from the CPLD.

4in1a, 4in1b - These have been decrypted, currently boot but stuck at 'Hardware Check' with an error. Need adjusting of the cpld_*() methods.

3do

Emulation is still preliminary. Needs DSPP core properly hooked up (should be similar if not same to the one used by the later Konami M2 HW).

4dpi

Preliminary driver. Hangs after booting irix from miniroot.

4enlinea

Needs proper UM487F device emulation. CPU logic seems quite off.

4enraya

strker - Stops with 'RAM no good' message.

4roses

Skeleton driver. The games' program ROM has been decrypted, but they have an undumped MCU which needs decapping or simulation.

8080bw

invasionrza - Bootlegs on slightly different hardware.

sisv1 - Some ROMs aren't dumped.

a2600

a2600_pop - 2 joysticks and 2 paddles are hooked up to the unit; unknown how.

a5105

There's a hang while scrolling and cassette loading (bit 7 of port 91) needs work.

a7150

Needs MMS16 (Multibus clone) and slot devices emulation, native keyboard and more work on the A7100 model.

aa310

RISC OS Draw app uses unimplemented copro instructions; needs ABORT line support to the ARM core; missing hard disc controller, serial interface, 82c711, podules expansions.

abc1600

TODOs are short/long reset (RSTBUT), CIO, hard disk and connect RS-232 port A.

= abc80

tkn80 - Specific features of this model aren't emulated yet.

ac1

ac1scch - Hardware differences aren't emulated yet.

acefruit

acefruit - Inputs aren't fully understood. Video in bonus game needs fixing.

starspnr - Most likely needs a redump of the program ROMs.

acommand

acommand - Inputs aren't fully understood. Requires a major rework of the artwork sub-system. Needs to be merged with cischeat.cpp driver.

adacp150p

ASCII printer adapter. Does not do much more than pass the extensive self-test.

adp

Driver seems almost complete, still marked as not working.

agat

Similar to Apple II (same bus architecture, keyboard and floppy interface), but video controller is completely different.

agat9 - Needs memory banking. Extensive todo at the top of the driver.

airraid

airraid, cshooter - GFX ROMs in black 'blobs'.

aleck64

mtetrisc - Uses additional 2d sprite overlay for tetrominoes gfxs, mostly working minus gfx decoding itself.

alesis

The driver seems quite flashed out, but has no notes on what's missing.

alg

Laserdisc games on Amiga 500 hardware. They all work in theory, but are waiting for a good quality laserdisc dump.

alien

Skeleton driver (SH4 based system). Has 2 MPEG2 decoder chips.

allied

Pinball games. Emulation is (almost) complete, but the missing simulation of the tables makes them unplayable.

alphasma

Needs work on ADB and PS/2. The charset ROM is wrong.

alphatpx

Preliminary driver. Currently only shows the initial boot message. I8085A based.

altos5

When running MP/M, dir command crashes the system.

amaticmg

Emulation of the type 2 and 3 boards is preliminary, thus only suprstar (board type 1) kinda works, though it errors out when inserting coins.

amerihok

Preliminary driver. Mechanical / screenless system. Uses a Z8 based MCU.

amiga

Amiga chips emulation lacks a lot of features.

ampoker2

arizna10 - Undumped PIC provides protection. Currently can't exit operator mode to get in game.

ampkr2jsp, ampkr2jspa -

amstr_pc

The driver seems quite flashed out, but has no notes on what's missing.

amust

Lots of work still needed. Lacks software to further improve emulation.

amuzy

Skeleton-ish. H8/3007 CPU (internal ROM apparently not used), barely documented Yamaha YGV625 sprite processor and CRTC and OKI M9810 for sound.

anes

ROM banking isn't done yet. Blitter isn't emulated so nothing gets shown on screen.

apc

Several major features still unimplemented, available software doesn't make use of them.

apollo

dn5500, dsp5500, dn5500_19i - Newer models aren't fully emulated yet.

apple2

space84 - Clone on different hardware.

apple2e

mprof3, prav8c - Clones on different hardware.

apple2gs

apple2gsmt - Prototype with some different hardware. Differences not emulated yet.

apple2gsr3p - A ROM isn't dumped.

apricotf

Needs CTC/SIO interrupt acknowledge, CTC clocks and sound emulation.

apxen

Needs boot ROM disable, wrap around mode, floppy, DMA, harddisk, keyboard, RS232, printer, colour graphics board.

arachnid

Mechanical game. Needs artwork with lamps support.

arcadia

mratlus, plldium, polyvcg, trakcvg -

argo

Needs devices hook-up and cassette UART on ports C1 and C3.

aristmk4

86lions - Runs on earlier, slightly different hardware.

clkwise - Needs redump of the program ROMs.

aristmk5

Hardware differences from the base Acorn Archimedes are not fully understood yet.

Shares timing issues like base AA.

arkanoid

arkatour2 - Undumped MCU.

hexaa - Protection hasn't been figured out yet.

armchamp

Mechanical arm simulation isn't perfect.

artmagic

shtstar - Runs on different hardware.

astrcorp

magibomba, westvent - Bad dump of a program ROM.

magibombb, magibombc, magibombf - Freeze due to unemulated protection.

magibombd, winbingoa Need correct sprite ROM dump.

magibombg - Needs correct "CPU code", EEPROM and sprite ROM dump.

tenpindx - This game used a physical hockey puck which the player slid down the bowling alley. Sensors on the other end picked up the location and velocity of the puck and simulated the pin behavior. Requires simulation of this input interface in order to be considered working.

at

Assorted PC-AT clones. Only preliminary emulation.

atari400

a1200xl - Bad dump.

a65xea, a130xe -

atarigx2

All of these games suffer from some advanced protection that affects them in different ways. Through some magic accesses in memory, data can be decrypted using some special key sequences that are not entirely understood. It's possible to find all possible data sources, run them through the decryption process on the real PCB, and then encode that information in the driver, and for some of the games it has been done. Only rrreveng and clones are missing.

rrreveng and clones - Unemulated protection. It's possible the same method used to break Moto Frenzy's protection could be used.

atarist

Emulation still preliminary. TODO is on top of the source file.

atarisy2

paperboyp - Prototype with possibly different hardware. Some program ROMs didn't read consistently and are suspected bad. GFX ROMs weren't dumped for this set.

atarittl

tank - Netlist has been added but needs debugging and it runs very slow.

atetris

atetrisb5 - Uses a large TTL board as substitute for Slapstic and Pokeys. Currently unemulated.

atlantis

The Zeus2 video chip needs more work.

atm

atm -

atpci

Pentium and PCI emulation still preliminar.

atvtrack

Preliminary driver.

avt

Needs CTC and daisy-chain.

ax145

Stops while checking the printer.

ax20

Skeleton driver.

b16

No documentation available, system boots only after some debugger trickery.

b2m

Preliminary driver. FDC support is broken, among other problems.

badlandsbl

Inputs aren't correctly hooked up, missing sprite-tilemap priority, colors. Sound hw isn't correctly hooked up.

balsente

triviaes4, triviaes5 - Though clearly derived by the originals in this driver, it uses different hardware, especially for the sound. Banking / ROM loading isn't figured out yet.

banctec

Preliminary driver.

banprestoms

Need emulation of the card printer / dispenser.

bartop52

Coins and timer were handled by Bartop system bios. Since bios dump is not available, regular Atari 5200 bios is used and game is marked as not working. Game cart is also marked as bad dump as it is done in "console style", i.e. one file for all game data.

bbc

torch301, torch725, abc110, acw443, abc310, reutapm, bbcmaiv, bbcmarm, discmate, discmon, cfa3000, cfa3000bp, econx25, autoc15, daisy, mpc800, mpc900, mpc900gx, sist1 - All have different hardware combinations which aren't implemented yet.

bcs3

bcs3a, bcs3b, bcs3c, bcs3d -

bebox

bert

Preliminary driver. Z8671 based.

bfcobra

beeline, inquiztr - Missing floppy disk image.

bfmsys85

Fruit machine hardware. Skeleton driver.

bfm_sc1

Fruit machine hardware. Skeleton driver.

bfm_sc2

m_bcgslm, m_brkfst and clones, m_bfocus, m_cpeno1, m_luvjob - Mechanical games imported from AgeMame. The fruit machine games don't work either.

gldncrwnhop - Has different protection from the parent.

quintond - Missing emulation of RS232 data link device (see BACTA Datapak specs for more info).

bfm_sc4

Fruit machine hardware. Most games pass the startup tests.

bigbord2

Main problem is floppy disk support is missing.

bigkarnk_ms

Heavily modified bootleg of Big Karnak running on the Modular System. Only preliminary work has been done.

bingoc

bingoc - Needs to be connected to the terminals. Sound banking could be wrong.

bingor

Protection problems? Video hardware don't make much sense.

bitgraph

bitgrphb -

bk

bk0010 - Error message at start. Thrown into monitor.

bk0010fd - Continually reboots. The system expects a ROM at A000.

bk0011m - Black screen at start, differences with the other systems in the driver aren't emulated.

blitz68k

Cadillac Jack sets - These games freeze while trying to print the redemption tickets. Also need the MCU dumped and emulated, since they currently relay on ROM patches to bypass the checks.

The other games - Undumped MCUs.

blockch

Paddle/ball sprite drawing is guessed, video timing is wrong, 2nd irq timing is guessed.

blueprnt

unkzilec - Only the GFX ROMs are dumped.

bmjr

Break key is unemulated.

bml3

bpmmicro

Universal device programmer. 286 based.

br8641

Preliminary driver based on guesswork. Needs documentation.

btime

tisland - The decryption seems good but needs a ROM patch for some opcodes. The ROM is confirmed good, so maybe some special feature of the DECO-7 CPU?

bublbobl

bub8749 - Uses a different MCU, dumped but needs to be hooked up.

bullet

Memory banking is broken.

bungo

Dump is incomplete and components are guessed as there's no documentation.

busicom

Addition and subtraction do not work.

buster

Skeleton driver.

bwidow

bwidowp - Prototype on different hardware.

by17

Pinball games. Emulation is (almost) complete, but the missing simulation of the tables makes them unplayable.

by35

Pinball hardware. Not playable without mechanical part simulation.

bzone

dsrtwars - Bootleg with different sound system. Mostly works but sound is very badly emulated.

c10

Driver currently gets to a loop where it waits for an interrupt.

c64

clipper - Hardware differences haven't been emulated yet.

c65

Preliminary driver.

cabaret

Not fully playable because of some pitfalls.

calchase

calchase - Has mangled Win 98 dump (need to type boot at DOS prompt), in-game sports some video bugs, inputs are sketchy and no steering is implemented.

hostinv - "DISK BOOT FAILURE", trying to save BIOS settings causes black screen (shadow RAM issue), disk dump itself doesn't seem ISO 9660 complaint (protection?)

calomega

comg123, comg164, comg187, comg227, comg230 - Bad/incomplete dumps.

candela

can09 - Preliminary driver: among other things needs keyboard, 6845 CRTC and FDC support.

canon_s80

Skeleton driver.

casloopy

Missing bios dump.

cat

Big TODO at the top of the driver.

cb2001

Encrypted CPU.

cbm2

bx256hp, cbm730 - The i8088 board isn't emulated yet.

cbm720_de - Missing chargen dump.

cchance

Imperfect hopper emulation makes this game to not coin up and gives "hopper time out errors" when you win.

cclimber

bagmanf - Bootleg on different hardware.

ccs2810

Floppy implementation needs work.

cdc721

Skeleton driver.

cdi

General CDI emulation suffers from incomplete simulation of the SLAVE and CDIC MCUs.

cedar_magnet

mag_drac - Bad dump.

centiped

magworma - Service mode works, game does not.

ceres

Needs startup/reset memory map, i/o device mapping, interrupt acknowledge, WD1002-05 Winchester/Floppy Disk Controller (WFC), keyboard, mouse.

cesclass

Needs custom layout for dual LCDs, artwork and lamps position needed to make progresses, U43 and U44 bad in Trap Shoot Classic, games are incredibly sluggish, irq sources are unknown, Trap Shoot Classic runs on a single LCD, needs mod.

cfx9850

Preliminary driver.

cgc7900

Skeleton driver.

cham24

Missing coins and timer due to unemulated Amtel MCU.

champbas

tbasebal - M68705 MCU isn't emulated yet.

chessmst

chessmsta - Figure out why it won't work, for starters it assumes z80 carry flag is set at poweron?

chexx

Electro-mechanical bubble hockey games.

chihiro

X-BOX hardware emulation is still preliminary, but some games boot, albeit slowly.

cischeat

armchmp2 and clones - Arm motor emulation is incorrect.

wildplt - Busted timings.

cit220

Preliminary driver. I8085A based.

ckz80

No documentation available, so driver is mostly guesswork. If fdc is enabled in address map, it hangs waiting for a fdc response. Otherwise, it displays an error, and you can press a key to try again.

clickstart

Preliminary driver. UNSP based.

cliffhgr

cliffhgra2 - Fails a start up check.

goaltogo - Laserdisc game. Works in theory, but is waiting for a good quality laserdisc dump.

cm1800

Peripherals aren't hooked up.

cmi

MASTER 'TIM' test fails. LGTST 'TIM' test is out of tolerance without 6840 hack.

cmmb

Banking not understood.

cntsteer

cntsteer - Needs better understanding of the communications and correct ROZ layer implementation.

gekitsui, zerotrgt and clone - Need better ROZ layer implementation.

cobra

Complicated Konami 3D hardware. Bujutsu works a bit better.

coco12

deluxecoco - Missing some ROM dumps.

codata

Very preliminary driver.

coinmstr

pokeroul, supnudg2 - Incomplete protection simulation.

trailblz - Question ROMs aren't dumped.

coinmvga

Interrupt generation is unknown and touch screen needs to be hooked up.

combatsc

bootcamp, bootcampa, combatscj, combatsct - Trackball isn't correctly emulated.

compc

Preliminary driver. I8088 based. Boots with a timer2 error.

compucolor

ROMs are badly dumped. Needs floppy hook-up.

comquest

Skeleton driver.

controlid

Fingerprint reader device. Very skeletonish.

coolridr

aquastge - coin pusher, some video bugs, never completes RAM test, some inputs aren't hooked up.

cops

Preliminary driver. Laserdisc game.

cortex

Skeleton driver.

cp1

Skeleton driver.

cps1

hkittymp - Needs wheel emulation.

sf2amf, sf2stt - Missing program ROMs dump.

varthb3 - Different video registers need emulating.

cpzodiac

Punching bag game with red dot matrix display. Z80 based.

crgolf

mastrglf - There's a custom CPU box, main cpu banking and communications with sub cpu aren't understood. Possibly protected.

crimson

Skeleton driver. MIPS based

crospuzl

Dies at POST with a SPU error.

crystal

donghaer, maldaiza - Protection PIC hasn't been dumped yet.

officeye - Protection PICs have been dumped but there isn't a pic16c727 core yet. Simulation is quite good, but there is still some instability.

wulybuly -

csplayh5

Implementation of DVD routing and YUV decoding, needs serial emulation in TMP68301 CPU core, game timings seem busted which could be due of missing DVD hook-up.

csplayh1 - runs on Super CD HW, Inputs doesn't work at all, slower than the others too.

cswat

The game utilizes a projector. Can it be simulated with external artwork? Interrupts need to be improved.

ctk2000

Keyboard. Emulation is preliminary. ARM derivative.

cubo

eldoraldg - Touchscreen is offset and cannot be calibrated, joystick buttons aren't recognized properly, has slight GFX bug with roulette ball.

lsrquiz - No player 2 inputs (ingame), wrong pitch for most gfxs, access violation during gameplay or on emu exit (microtouch?).

lsrquiz2i - Wrong pitch for some gfxs, access violation during gameplay (microtouch?).

lsrquizg - Doesn't accept coins, no player 2 inputs (ingame), wrong pitch for most gfxs, access violation during gameplay or on emu exit (microtouch?).

odeontw - 'Invalid NVRAM', accesses area $6xxxxx and claims invalid RAM config if bypassed.

odeontw2 - Resets halfway thru "please wait" in service mode, therefore NVRAM cannot be inited.

cv1k

mmmbanc - Needs touch screen emulation handled via SH4 serial

cxhumax

ROMs are badly dumped / missing.

cz101

Currently seems to hang while processing the serial ports (midi). The uPD7810 core is lacking the externally clocked serial mode.

d6809

Most devices aren't hooked up. Skeletonish.

daruma

Printer. Very preliminary driver.

datacast

Unimplemented keypad, incomplete SAA5240 emulation.

dbox

Needs GALs dump / decoding, debug terminal and demuxer work.

dbz

dbz2bl - Bootleg on different hardware. Heavy priority / GFX issues, no sound.

dc_atomiswave

Most games show something and some are playable, but emulation is still incomplete.

dccons

Dreamcast emulation is preliminary. Big TODO at the top of the driver, not extensively tested.

dct11em

Skeleton driver.

ddenlovr

momotaro - Protection + some ROMs are badly dumped.

ddragon

ddragon6809, ddragon6809a - Bootlegs on different hardware, encrypted.

deadang

popnrun and clone - GFX ROMs aren't dumped. They are inside an epoxy block, similar to the Air Raid one.

dec0

automat - Bootleg on different hardware. Minor video glitches.

bandit - Incomplete decbac chip emulation causes bad GFXs.

mastbond, secretab - Bootleg on different hardware. Unemulated layer scrolling and banking.

ffantasybl - Hangs after killing Lamia. Might have to do with the M68705 MCU, which isn't dumped.

dec8

ghostb3a - The game hangs as gameplay starts. ROMs confirmed working on PCB. MAME sync problems?

deco32

gunhard, lockload, lockloadu - lightgun hookup not completely understood, randomly locks up

deco_ld

The driver needs better video e I/O emulation, laserdisc hook-ups.

deco_mlc

skullfng and clones - Random hangs sometimes.

stadhr96j2 - Stops with a mismatch between mother board and cart country code.

decstation

MIPS family based. Preliminary driver.

dectalk

Extensive TODO at the top of the driver.

deshoros

Needs graphics emulation through artwork system and printer emulation.

design

Tobacco vending machines. Don't accept coins, possibly because of unemulated coin selectors.

dfs500

Emulation of the video hardware (DSP signal path) for GFX processing is still needed.

dgn_beta

Machine never boots.

digel804

Needs removing of the ACIA hack in digel804_state::acia_command_w, minor finishing touches to i/o map, EPROM socket stuff (ports 0x40, 0x41, 0x42 and 0x47) and artwork.

digijet

Engine Control Unit (ECU). Skeleton driver. Uses an I8049.

digilog320

Needs finishing floppy hookup; SCC interrupts; unknown DUART inputs/outputs; RS232; RTC; artwork with LEDs.

dim68k

Very preliminary driver. Big TODO at the top of the driver.

dkong

dkongjrc, dkongddk - Graphic ROMs not switched.

dlair

Laserdisc games. Work in theory, but waiting for a good quality laserdisc dump.

dm7000

Preliminary driver.

dmax8000

Needs parallel port, centronics port, AUX serial port and FDC/FDD/HD setup.

dmndrby

Electrocoin on snk hardware. Needs better video emulation. Enters service mode while attract mode is running.

dms5000

Skeleton driver.

dms86

Preliminary driver.

docastle

asoccer, idsoccera, idsoccert - See MT05419.

dolphunk

It is not possible to save / load programs.

dpb7000

Disk Sequencer Card emulation is preliminary.

drdmania

Darts machine with video. Z80 based. One ROM dump is bad.

drw80pkr

Driver shows something, but emulation is still incomplete. I8039 based CPU with CRTC6845 video and AY8910 sound.

ds90

Skeleton driver. M68010 based.

dsb46

Preliminary driver.

dual68

Skeleton driver.

duet16

Floppy not hooked up correctly, still WIP.

dvk_kcgd

Needs a K1801VM2 CPU core (interrupts and EVNT pin, full EIS set, other insns).

dwarfd

qc, quarterh and clones - Missing laserdisc dumps.

dynax

majrjhdx, ougonhai, ougonhaib3, tenkai2b - Missing dump of the internal ROM of the TMP91640.

ec184x

ec1845 - Differences to the other models aren't emulated yet.

ec65

Preliminary driver.

ecoinf2

Skeleton driver for fruit machine games.

ecoinf3

Skeleton driver for fruit machine games.

ecoinfr

Skeleton driver for fruit machine games.

elan_eu3a05

airblsjs, buzztime, pvmilfin - Preliminary emulation.

carlecfg - Unimplemented GFX modes, big GFX glitches.

pvwwcas - Controls aren't working yet.

rad_tetr - Player 2 inputs don't work.

sudoelan - Might be slightly different hardware.

elan_eu3a14

Preliminary driver.

electron

btm2105 -

elektronmono

MCF5206E based. Skeletonish.

enmirage

Needs Four Pole Low-Pass Voltage Controlled Filter section, external sync signal, foot pedal, ADC feedback, piano keyboard controller, expansion connector, stereo output.

eolith

raccoon - Game animation & timers seem too fast.

epos

catapult, revenger - Bad dumps.

esd16

fantstry and clone - Playable, but no sound because of an undumped PIC.

esh

LD TROUBLE appears at POST. Sync/timing issue? Performance spike after some time of gameplay, CPU comms gets corrupt?

esq1

esqasr

Skeleton driver.

esqkt

ts10, ts12 -

esqmr

Skeleton driver.

eurit

Preliminary driver. ISDN-Telefon. M37730S2 based.

europc

eva

Preliminary driver. TMS 1000 / COP420 based.

exelv

EXL 100 cannot be emulated because the ROMs are not dumped. EXELTEL stops early in the boot process and displays a red error screen, presumably because the I/O processor is not emulated.

exidy440

showdown4 - Different type of protection wrt to the parent.

f-32

royalpk2 - It will soft-lock when attempting to use either settings-save options in the service menu.

f1gp

f1gpb - Bootleg on different hardware.

f387x

Computer. F8 based. Driver is skeleton-ish.

f4431

Missing emulation of character attributes (RAM at 0xc000), cursor, 132 column mode, smooth scrolling, timings, printer.

facit4440

Keyboard isn't emulated.

falco500

falco5220e - Bad dump. ASIC emulation is incomplete.

fanucs15

Skeleton driver.

fanucspmg

Needs verifying VRAM hookup, hooking up enough keyboard to get it to boot a floppy.

fastfred

boggy84b2 - Missing the dump of a program ROM.

fastinvaders

Games reset. Schematics are available.

fc100

Understand how 600 baud is selected for cassette. Hook up graphics modes and colours. Unknown i/o ports. Needs cart software (current code is just a guess).

fccpu30

Crashes during boot.

firebeat

popn4, popn5, popn6, popn7, popn8, popnmt, popnmt2, popnanm, popnanm2 - Require DVD CHD support.

fitfight

hotmindff - Scrolling offsets + inputs need to be fixed.

fk1

Preliminary driver.

flashbeats

Preliminary driver. H8/3007 based.

fm7

fm11, fm16beta, fm7740sx - Extra features not implemented.

fmtowns

Video emulation is far from complete.

fontwriter

Extremely preliminary driver. The M37720 core is missing DMAC support.

fp1100

IRQs aren't emulated, cassette, FDC and keyboard don't work.

fp200

Video emulation is preliminary.

fp6000

FDC/HDD and cassette saving don't work.

freekick

countrun - Main program inside of custom CPU block.

countrunb2 - Possible bad dump, or encrypted.

fresh

Preliminary driver. M68000 based.

ft68m

Skeleton driver.

funkball

Preliminary driver. PC based hardware (Cyrix GX + 3DFX).

funworld

fw_a7_11, fw_a7_11a, fw_a0_1, jokcrdep - Different hardware with epoxy block, to be reverse engineered.

jolyjokrc - Bad program ROM.

multiwinb - Encryption not figured out yet.

royalcrd_msx , royalcrd_nes and clone - Stealth games which combine the poker game hardware and the console hardware.

gaelco2

play2000_50i - Bad dump.

aligatorp, chmppool, srollnd - Missing ds5002fp dump.

gaiden

mastninj - Sprites, sound and y-scroll need fixing.

gal3

In need of laserdisc dump. Skeleton driver.

galaxian

amidarc - Resets when starting a game.

ckongcv, ckongis - Bootleg on different hardware.

dingoe - Probable bad dump and encryption.

highroll - Auto starts game after inserting coin, bad cards GFX, bad inputs response, not all inputs are mapped.

jungsub - Different hardware, needs better GFX handling and one GFX ROM is bad.

ncentury, scramblebun, scrammr - Stuck at boot. IRQ isn't enabled correctly. Protected?

mooncrs5, mutacion, supergx - Bad dumps.

olibug - One of the GFX ROMs is bad. Uses the Galaxian PROM, which gives bad colors(?).

tenspot - Menu isn't working yet.

warofbugg - Bootleg on slightly different hardware.

galaxold

drivfrcsga, spcwarp - Bad dump.

trvchlng - Questions ROMs aren't dumped.

galeb

Cassette isn't working yet.

galivan

youmab, youmab2 - Weird bootlegs, they have logic issues (always invincible, power ups can be freely selected).

galpani2

Kaneko protection MCU with internal rom, managing CPU comms. Decap should possible, should be the same for all games / sets.

galpanic_ms

Heavily modified bootleg of Gals Panic running on the Modular System. Only preliminary work has been done.

gambl186

Missing At89c52 dump. EEPROM behaviour still buggy.

gameace

hotbody2 - Program ROM isn't dumped.

gamtor

Skeleton driver for fruit machine games.

gb

mduckspa - Clone with some differences.

gba

robotech - Single game reissue of "Robotech - The Macross Saga (Euro, USA)" on the GBA but with double sized ROM (BIOS replacement in first half?) and other mods. It is unclear how compatible this is with standard hardware.

gberet

gberetb - Needs correct PROM decoding. As is, GFX are too mangled to play it.

generalplus_gpl16250_nand

Newer hardware than the one in vii.cpp, new opcodes aren't emulated yet.

generalplus_gpl16250_rom

Newer hardware than the one in vii.cpp, new opcodes aren't emulated yet.

generalplus_gpl16250_romram

Newer hardware than the one in vii.cpp, new opcodes aren't emulated yet.

generalplus_gpl16250_spi

Newer hardware than the one in vii.cpp, new opcodes aren't emulated yet.

generalplus_gpl16250_spi_direct

Newer hardware than the one in vii.cpp, new opcodes aren't emulated yet.

generalplus_gpl162xx_lcdtype

bkid218, pcp8718, pcp8728 - Menus aren't working properly yet.

generalplus_gpl32612

Newer hardware than the one in vii.cpp, new opcodes aren't emulated yet.

geniusiq

iq128, iq128_fr, iqtv512 - Very preliminary driver.

ggconnie

Hardware is PC-Engine Supergrafx based. RTC & hopper not emulated.

giclassic

Preliminary driver.

gizmondo

Preliminary driver.

gkigt

Preliminary driver. Needs hookup of the QUART devices, and fix "QUART COUNTER NOT RUNNING" error message; interrupt system hookup; understanding of what's "netflex" device. Furthermore, the CMOS doesn't seem to get properly initialized. Also, the ms72c set seems to have extra checks.

goldart

DS5002FP based. Preliminary driver, GFX, sound and inputs aren't properly emulated yet.

goldngam

Preliminary driver.

goldnpkr

falcnwldc - Main CPU / MCU communications aren't correctly implemented yet.

goldnpkd - You always get a winning flush. Unemulated protection?

maxidpkr - Undumped 68705P5 MCU.

pokerdub - Missing one program ROM.

wldwitchb, wldwitche, wtchjackc -

witchcdk - A ROM is corrupt.

goldstar

3cdpoker, 3cdpokera, cmfb55, luckylad, pkrmast, prkmasta, srmagic, super972 - They need work on inputs / dips.

animalw, ll3, wcherry - Only preliminary work has been done.

aplan, chryangla, cmast99, cmast99b - The game appears to be stuck in a loop resetting itself after initialising NVRAM.

bonusch - Undumped MCU.

cb3c - Needs correct memory map and one GFX ROM is a bad dump.

cb3f - Encryption not completely figured out.

cherry96 - Different hardware.

chryangl, chryanglb - Hangs when betting or after a couple of attract mode cycles. Protection related?

cmast92 - Graphics ROMs aren't dumped yet.

cmast97 - PROM decode needs fixing, GFX loading is wrong.

cmasterbv, cmv4a - Missing switch between normal and "stealth" game.

cmasteri - ROMs contain only half of what they should, but dump sizes are confirmed wrt to ROM chip type.

cmtetrsb - Soon after boot it shows garbage due to wrong graphics banks.

crazybonb, wcat3a - Decryption should be good. Possibly needs a different machine driver?

eldoradd - Just ROM loading done, not looked at yet. Hardware is similar to cmast97.

jkrmast, jkrmasta - Preliminary emulation.

luckybar - mc68705 MCU.

magoddsc, magoddsd - Custom encrypted CPU block.

nd8lines - Needs correct PROMs decoding and inputs.

noved - Needs GFX2 region decryption / decode, controls.

feverch, mbs2euro, megaline - Need more work in memory map, inputs, and reels alignment.

nfm and clone - Need decoding of the girls' GFX ROM.

roypok96c - Stuck at the Program Check screen.

super7 - Needs GFX and palette work. First time it boots and works, with written NVRAM it stops waiting for initialization. Slightly wrong decryption?

super9 - GFXs aren't decoded yet.

tcl - Encrypted.

war3cb - Address scrambling needs to be checked.

wcat3 - Encryption not completely broken, can be seen running after a couple soft resets.

gp_1

Pinball games. Emulation is (almost) complete, but the missing simulation of the tables makes them unplayable.

gp2x

Skeleton driver.

gp32

Driver is quite advanced, but isn't fully working yet.

gpworld

Laserdisc hardware. Works in theory, but is waiting for a good quality laserdisc dump. Does have a small list of TODO items that could be looked at prior to a disc dump.

grchamp

grchampa - Uses different ports. Possible bad dump.

grfd2301

Preliminary driver. Dump isn't complete.

gsspade

Mechanical redemption game? Only the sound board CPU ROM is dumped.

gstriker

gstriker and clones - Several GFX features aren't emulated yet, making the game almost unplayable.

vgoalsoc, vgoalsoca - Tecmo MCU providing jump addresses etc. Has direct access to entire CPU bus, prevents code modification (MCU writes 'ROM ERROR' if you change ROM). ROZ pitch difficult to understand.

gsword

josvolly - Incomplete MCU hook up.

gticlub

thunderh and clone - They use an additional top board for sound, network and analog control functions.

gts1

Pinball games. Emulation is (almost) complete, but the missing simulation of the tables makes them unplayable.

guab

crisscrs - Missing disk image dump.

h89

Skeleton driver.

harddriv

steeltalp, hdrivairp - Prototypes, possibly running on slightly different hardware.

hazeltin

Preliminary driver.

hazl1420

Preliminary driver. Chargen not dumped.

hds200

Needs fixing the SCN2674/Z80DMA hookup, missing keyboard keys and RS232 control lines.

hh_cop400

vidchal - Needs videotape support.

hh_hcms40

bombman, gdefender, ggdman, ktparman, puckimon, tkjmaru, wantgman - Missing artwork.

hh_pic16

pabball, uspbball - Preliminary drivers.

hh_sm510

nsmb3, nsmw - Missing LCD scan.

hh_tms1k

bship and clone, elecbowl - As far as MAME is concerned, the game is emulated fine. But for it to be playable, it requires interaction with other, unemulatable, things (eg. game board/pieces, playing cards, pen & paper, etc).

tithermos - Temperature sensor comparator isn't emulated yet (right now just the digital clock works).

hideseek

Missing the internal ROM dump of the HD64F7045F28 main CPU.

highvdeo

bingopd, cuncino, grancapi, magicbom, newtiger, saladue and clone, zoomania and clone - Need correct / verified inputs.

unksmk - Doesn't respond to inputs. Protected.

hikaru

Skeleton driver.

hitparade

Juke box. TMS1300 based. The mechanical parts aren't emulated.

hitpoker

Protection: needs dumping or simulating PIC.

hng64

ROZ layer rotation not understood, some 3d glitches, several priority issues (i.e. buriki gameplay and attract mode), sams64_2 flickers like mad and "press start button" always displayed in game, racing games uses unemulated network CPU which most likely interferes with logic and currently kludged to work to some extent.

homedata

mirderby - Preliminary driver. Might be protected.

homelab

Preliminary driver. Cassette support needs to be fixed, among other things.

horizon

hornet

sscope and clones, sscope2 and clones -

terabrst and clones - Missing gun emulation.

terabrstaa, terabrstja, terabrstua - Missing gun emulation, won't boot due to issues with the cgboard/konppc.

thrilldbu - Heavy GFX glitches, fails wheel motor test.

hotstuff

Preliminary driver.

hp_ipc

hp9808a - Preliminary driver.

hp16500

Preliminary driver.

hp2620

Keyboard isn't emulated.

hp3478a

Runs, AD LINK ERROR on stock ROM due to unimplemented AD link.

hp48

hp39g -

hp49gp

Preliminary driver.

hp95lx

Native keyboard isn't emulated. Driver still preliminary.

hp9k

Boot tests fail.

hp9k_3xx

Preliminary driver.

hprot1

hprot2r6 - LCD commands are sent, but nothing shows up on screen. Needs ADM695AN emulation.

hprotr8a - Loops during boot displaying an error message related to low power supply voltage. Needs ADM695AN emulation.

hpz80unk

Skeleton driver. Needs banking and peripherals support.

hshavoc

Genesis hardware, but uses a PIC to control state based encryption. All the code that matches the Megadrive version has been decrypted, but the extra code (startup code, coins etc.) appears to have some annoying extra encryption.

hunter2

Preliminary driver. Without software to test it, it's difficult to progress with the emulation.

hx20

Needs emulation of: keyboard interrupt, LCD controller, serial, SW6 read, RS-232, microcassette, printer, ROM cartridge, floppy TF-20, barcode reader. Might need a M6800 core rewrite.

i7000

Preliminary driver (NSC800 based).

ibmpc

ibm5140 - It doesn't boot.

ibmpcjr

ibmpcjx - Dump is incomplete.

ice_bozopail

Redemption game. Mechanical parts aren't emulated.

icebox

Z80 based. Floppy drives aren't hooked up. Unknown ports.

icecold

Mechanical arcade games which need simulation of the mechanical part to be playable.

idpartner

Preliminary driver. Z80 based.

if800

Skeleton driver. I8086 based.

igs017

mgcs - IGS029 protection needs more work.

tarzan - Missing sprites and sound ROM, imperfect tiles decryption.

tarzana - Missing IGS029 protection, missing sprites and sound ROM.

igspoker

cpoker210ks, cpoker300us - Protection handling and inputs / outputs need to be verified.

kungfu - Differences to the other games in the driver aren't emulated yet.

kungfua, stellecu - Bad / incomplete dump.

imacg3

Very preliminary driver.

imsai

Banking and dip-switches aren't implemented. I8085 based.

indiana

Preliminary driver.

indigo

Skeleton driver.

indy_indigo2

indigo2_4415 - The different hardware isn't emulated yet.

informer_207_376

Two ROMs need a redump.

informer_213

Terminal. 6809 based. The ASIC needs to be figured out.

interpro

Preliminary driver.

intrscti

Undumped program ROM in an epoxy block.

intv

intvkbd - Has additional components / devices (i.e. tape) which aren't emulated.

ipc

ipc - Dump incomplete.

ipds

Skeleton driver. I8085A based.

iris_power

Skeleton driver. MIPS based.

irisha

Preliminary driver. I8080 based.

ironhors

farwest - Bootleg running on different hardware.

isbc

rpc86, isbc86, isbc8605, isbc8630, isbc286, sm1810 - Preliminary driver 8086 / 286 based.

isbc660

Needs more Multibus cards emulated and installed.

iskr103x

iskr1030 - Keyboard test doesn't pass.

island

Unemulated features of the DS80C320 CPU and preliminary driver.

istellar

Laserdisc game. Has a small list of TODO items that could be looked at prior to a disc dump.

istrebiteli

motogonki - Preliminary. Shows something on screen.

itc4

Skeletonish. Temperature controller. Z80 based.

itech8

stratabs - Controls aren't hooked up.

itt3030

Keyboard isn't properly hooked up. Other problems at the top of the driver.

jackpool

Needs better understanding of the master/slave communications, better EEPROM and NVRAM hook-up.

jade

If you hit a key as soon as it is started, the system will present a prompt and work. Otherwise it runs into the weeds because the ROM banking isn't yet emulated.

jaguar

jaguar, jaguarcd - Currently the driver is geared toward supporting the cojag arcade games. Jaguar console support is very poor, most games aren't properly playable or have severe performance issues or crashes related to the unsafe blitter code.

jokrwild

Missing random number generator, inputs and sound.

jonos

Skeleton driver. I8085A based. No info available.

joystand

Sticker machine which needs camera, printer and light pen support to be useable.

jpmimpct

buzzundr, monspdr, snlad - Incomplete dumps.

jpmimpctsw

all sets but j6aceclb, j6big50, j6bigbuk, j6bnza, j6camelt, j6cascz, j6gogold, j6guab, j6hapyhr, j6kungfu, j6mono60, j6montlk, j6roller, j6sonic, j6untch and relative clones - Need correct layouts and settings.

jpmsru

Missing layouts.

jpmsys5

cashcade - Incomplete dump? Shows a loading error.

monopldx1 - Missing questions?

jpmsys5sw

The mechanical games aren't emulated yet.

jr100

Paste drops many characters. Cassette not working correctly

jr200

Wrong timings. Also needs a MN1544 4-bit CPU core and ROM dump.

juku

Needs display mode 384x200, sound, possibly tape and network. Floppy interface isn't understood, though it works enough with the only disk available.

jungleyo

With a clean NVRAM MAME needs to be soft reset after init or the game will trip a '1111 exception' (caused by invalid opcode executed at 0x102, incomplete decryption most likely); likewise anything in the 0x100-0x1f7 range doesn't seem valid at all; the game sometimes expects 1+ coins even if player has available points (and freezing with "COIN" text blinking), very unlikely to be intended behaviour?

jupiter

Preliminary driver. Devices aren't connected yet.

k1003

Skeleton driver. I8008 based. Keyboard isn't emulated.

k28m2

LCD isn't emulated.

k8915

Skeleton driver. Z80 based. Chargen ROM isn't dumped.

karnov

karnovjbl - Bootleg. Uses a different MCU (NEC D8748HD) which needs simulation or, if possible, dumping.

kaypro

Most machines are incompletely emulated. The problems listed in the driver are:

kaypro1084 - Boots from floppy, but needs hard drive added.

kaypro4a - Floppy not working.

kayproiip88, kaypro484p88 - Works as a normal Kaypro 4, extra hardware not done.

omni2, omni4 - I/O board isn't emulated.

robie - Has twin 2.6MB 5.25 floppy drives which aren't supported, no software available.

kc

kikikai

mexico86a -

kingdrby

cowrace - Incomplete dump.

kingpin

dealracl - Partially a bad dump and / or wrong ROM loading.

klax

klax5bl3 - Audio CPU has encrypted opcodes.

kminus

Computer. Z80 based. No notes on what's missing.

koftball

Incomplete protection simulation.

konamigv

btchamp, kdeadeye, tmosh and clones - All games on this system suffer from a corner case involving audio track playback in the SCSI CD-ROM emulation.

konamigx

opengolf and clones, racinfrc and clones - These games use a special ROZ layer generated by the "PSAC4" custom IC which appears to include a height map.

konamim2

btltryst - Unemulated GFX modes make the game too glitchy to be playable.

evilngte, totlvica, totlvicj, totlvicu - They get stuck during boot.

heatof11 - Hangs if Japan is selected. Timing related, as setting perfect interleave fixes it.

konblands

Missing laserdisc dump.

konendev

Most dumps are incomplete. Work has been done and at least one romset goes in-game.

konmedal

slimekun -

tsururin - Resets after initial ROM / RAM test. IRQ related.

konmedal020

Preliminary emulation.

konmedal68k

crossmg2, fruitsmg - Mechanical parts aren't emulated yet.

dobouchn - Controls need verifying.

pwrchanc, spcpokan - Colors are wrong, inputs not verified.

unkkonmd - Stops with network ID error.

kopunch

Boxing bag game. Sensors aren't emulated, so it isn't "playable".

kron

Needs keyboard fixing and understanding how to hook up the real char table.

krz2000

TMP68301 based. Skeletonish.

ksys573

Game suffer from incomplete PSX-based hardware emulation and some are missing emulation of the external digital sound and I/O board.

ktm3

Only a few address lines are decoded at all. The resulting mirroring might not be accurately emulated yet.

kyocera

pc8201 - Cassette's not working, floppies aren't hooked up.

pc8201a - Cassette's not working.

npc8300 - Doesn't boot.

labtam

Needs emulation of additional cards.

laser3k

Keyboard is only partially emulated, misses RGB graphics mode emulation, FDC C800 page appears to be inside the FDC cartridge (a dump is needed). Also misses Centronics printer port and cassette emulation.

lastfght

Game speed seems to be completely wrong, timers and player movement too fast?

laz_aftrshok

Mechanical game, needs controls simulation.

laz_ribrak

awetoss - Mechanical game, needs controls simulation.

lbpc

PC. V40 based. Inputs aren't hooked up.

lcmate2

RTC doesn't remember the time, alarm doesn't work and Reset/On button needs to be added.

ld50

Electronic drums. I87C52. Dream SAM9793 and Burr-Brown PCM1717E DAC aren't emulated.

legionna

cupsoc and clones - Complex Seibu 'COP' protection device. Most functions have been emulated, but glitches remain which makes games not completely playable.

leland

aafbb - One of the program ROMs is a bad dump.

lethalj

franticf and clone - Directional inputs (wheel) don't work yet.

lg_dvd

USB DVD writer. Skeleton driver. MT1839 based.

lgp

Laserdisc game. Has a small list of TODO items that could be looked at prior to a disc dump.

lindbergh

Skeleton driver. Pentium 4 / Celeron based.

lisa

Lisa OS doesn't boot.

lnw80

Floppies don't work.

lucky74

excitbj - The program ROM for the terminal isn't dumped.

lucky74b - The program ROM seems incomplete or encrypted in some smart way.

lw700i

Keyboard matrix hasn't been completely figured out yet.

m10

ipminvad1 - Incomplete dumps.

m107

kftgoal, wpksoc - Missing EEPROM hook-up.

m20

Needs a proper Z8001 CPU core.

m24

m3

Unfinished floppy hookup (no available software to test it). Not all keys are mapped.

m62_bkungfu

Blitter data is encrypted and MCU is undumped.

m6805evs

Skeleton driver.

m72

loht_ms, lohtb, rtypem82b, rtype2m82b - The bootleg hardware is different to the original hardware.

m79152pc

Skeleton driver. Z80 based.

m92

nbbatman2bl - Bootleg with different sprite system, MCU as soundcpu, OKI samples for music/sound.

maciifx

macpdm

macprtb

Via6522 emulation is imperfect and causes numerous bugs.

macpwrbk030

Via6522 emulation is imperfect and causes numerous bugs.

macquadra700

Via6522 emulation is imperfect and causes numerous bugs.

macs

macsbios -

mac2bios -

kisekaem -

kisekaeh -

cultname -

magic10

hotslot, magic102 and clone, mcolors, mcolorsa, suprpool - Missing dump of the internal ROM of the HD6473308cp10.

magicard

belslots, hotslots, magicle, quingo - Fail on I2C BUS ERROR - protection device missing.

bigdeal0 - Locks with 68070 continually executing address error exception.

dallaspk - Requires protection device (serial port ?).

kajotcrd - Gets stuck during initialisation.

magicard -

magicrd1a, magicrd1b, magicrd1d -

magicrde, magicrdea - Alarm when credit is added and credit is then cleared.

magicrdec - Fails on "OUT OF RANGE ERROR".

magicrdj, magicrdja - Fail on "ERROR IN SETTINGS".

magictg

Preliminary driver, almost works.

malzak

malzak, malzak2 - Sprite collision detection doesn't fully work.

manohman

Preliminary driver.

marinedt

Collision detection has some problems.

marywu

mastboy

mastboyiv2 - Needs a different MCU program.

max80

Computer. Z80 based. Currently stuck because floppy reading fails.

maygay1bsw

Mechanical game imported from AGEMAME.

maygayv1

Skeleton driver for fruit machine games.

mbc020

Computer. M6512 based. Skeletonish driver.

mbee

mbee128, mbee128p, mbee256, mbee56, mbeepp, mbeett - Hardware differences haven't been emulated yet.

mc1502

pk88 - Missing video and keyboard emulation.

mc8030

Very little documentation available, so the driver is mostly guesswork. Z80 based.

mccpm

FDC is implemented but there's no software to test it.

mcr

nflfoot - CED-based disk game. Has gory Z80-based serial I/O interface that is not understood. The CED player interface is undocumented. A poor quality rip exists of the video (probably the best we will get). There is a second CED disk with different teams playing which we do not have access to.

mdconsole

mdisk

It boots from floppy, so presumably only needs an emulated main system to work.

mediagx

Mainly just need the inputs hooked up, which are mapped to the parallel port via a JAMMA interface.

megadriv_acbl

barek2mb - PIC is dumped but hasn't been hooked up yet. Crude simulation causes problems in detecting coins.

bk3ssrmb - The mechanism to switch between the 2 games hasn't been identified yet.

jparkmb, twinktmb - Undumped PIC controls at least coins and dips. Crude simulation causes problems in detecting coins.

sonic3mb - Undumped PIC.

megadriv_rad

ra145 - Bad dump.

megadriv_sunplus_hybrid

SunPlus side isn't hooked up.

megadriv_vt_hybrid

VT side isn't hooked up.

megaplay

mp_bio - Frequently softlocks after continue, usually on the 2nd stage.

mp_shnb3 - Game softlocks if you coin during the intro sequence.

megatech

Incorrect behavior at time out and there are some sms based games which aren't yet fully supported.

menghong

HY04 protection needs simulation (controls tile RNG at very least and possibly colors). EEPROM isn't hooked up yet.

merit

dodgectya, dodgectyb, dodgectyc - Text doesn't appear.

mosdraw - Needs RTC and printer hook up.

meritm

megat5a - Bad dump.

mes

metalmx

Skeleton driver. Extremely complex prototype hardware.

metro

metabee - Hopper isn't emulated, so game doesn't start.

poittoc - One of the program ROMs isn't dumped.

puzzlet - In game timer doesn't decrease.

mfabfz

Driver still in the early stages of development. No inputs are hooked up.

mg1

Misses hard disc controller and mouse emulation.

mice

Very preliminary driver. No schematics available.

micro20

Skeleton driver. Uses a 68020 and a 68881 FPU.

microdec

Floppy doesn't work and timer chip isn't hooked up.

micronic

Needs IR I/O port, LCD contrast and backlight emulation.

microterm_f8

WIP driver. Missing some GFX modes.

midyunit

mkrep -

midzeus

crusnexo, thegrid and clones - These Zeus II-based games use a proprietary 3D graphics chip that has no available documentation.

mikro80

Cassette save produces incorrect signal.

minib

Keyboard isn't working correctly.

miniboy7

bejpoker, sminiboy - Missing inputs: HOLD 1 and SMALL.

minicom

miniforce

Very preliminary driver.

miniframe

Preliminary driver. M68010 based.

mips

rc3230, rs3230 -

missamer

Mainly there's no ball physics simulation.

missile

mcombat, mcombata, mcombats - Bootlegs on different hardware.

missilem - This kit combines Missile Command and Super Missile Attack on ddaughterboard plugged into the main pcb cpu slot.

mitchell

pangbp - Has an extra Z80 with battery backed RAM for protection. RAM dump not available.

pkladiesbl ' - Needs CPU "decryption".

pkladiesbl2 ' - Needs inputs, sound and GFX fixes.

spangbl2 - Bootleg on different hardware.

mits680b

Skeleton-ish. M6800 based.

ml20

Needs currently unimplemented V25 features (serial, etc.).

mk85

Skeleton-ish. K1801VM2 based.

mk90

mkit09

model1

netmerc - Guesswork incomplete on the math copro dsp functions and program impossible to dump without decapping.

vf - Collision detection is broken due to imperfect TGP RAM port emulation or hookup.

model2

Implementation of the 3D systems is either guesswork (Model 2, 2A) or incomplete (Model 2B, 2C).

rascot2 - Probably part of a multiple unit setup (server, terminals, video boards).

model3

Driver is still preliminary. Most games boot and show something.

monzagp

Preliminary driver. Possibly missing a ROM.

moo

moomesabl - Bootleg on different hardware. Sprite ROMs weren't dumped for this bootleg set.

mpc3000

Preliminary driver. NEV V53 CPU and L7A1045-L6048 sound DSP emulation is preliminary.

mpf1

mpf1p - Bad dump.

mps1230

Printer. Basically a skeleton driver.

mpu1

Missing layouts.

mpu3

Most games fail to boot, giving the CPU a 'WAIT' instruction then sitting there; some complain about Characterizer (protection) and then do the same; a few boot to show light displays with no LED text; some display misaligned LED text; many run VERY slowly, even when the CPU is inactive (inefficient MAME timer system overhead?).