Unidasm is MAME's universal disassembler. The details below come straight from the MAME documentation. To be honest, 99.9% of MAME users will never need to use this program, but here's some details anyway.
unidasm <filename> -arch <architecture> [-basepc <pc>] [-mode <n>] [-norawbytes] [-flipped] [-upper] [-lower] [-skip <n>] [-count <n>]
8x300 h6280 m58846 powerpc tms1000
adsp21xx h8 m6502 pps4 tms1100
alpha8201 h8h m6509 psxcpu tms32010
alto2 h8s2000 m6510 r3000be tms32025
am29000 h8s2600 m65c02 r3000le tms32031
amis2000 hc11 m65ce02 rsp tms32051
apexc hcd62121 m6800 s2650 tms32082_mp
arc hd61700 m68000 saturn tms32082_pp
arcompact hd6301 m68008 sc61860 tms34010
arm hd6309 m6801 scmp tms34020
arm_be hd63701 m68010 scudsp tms57002
arm7 hmcs40 m6802 se3208 tms7000
arm7_be hp_hybrid m68020 sh2 tms9900
arm7thumb hp_5061_3001 m6803 sh4 tms9980
arm7thumbb hyperstone m68030 sh4be tms9995
asap i4004 m68040 sharc tp0320
avr8 i4040 m6805 sm500 tx0_64kw
capricorn i8008 m6808 sm510 tx0_8kw
ccpu i802x m6809 sm511 ucom4
cdp1801 i8051 m68340 sm590 unsp
cdp1802 i8052 m68hc05 sm5a upd7725
clipper i8085 m740 sm8500 upd7801
coldfire i8089 mb86233 sparcv7 upd7807
cop410 i80c51 mb86235 sparcv8 upd7810
cop420 i80c52 mb88 sparcv9 upd78c05
cop444 i860 mcs48 sparcv9vis1 upi41
cop424 i8x9x minx sparcv9vis2 v60
cp1610 i8xc196 mips3be sparcv9vis2p v810
cquestlin i960 mips3le sparcv9vis3 x86_16
cquestrot ie15 mn10200 sparcv9vis3b x86_32
cquestsnd jaguardsp nanoprocessor spc700 x86_64
ds5002fp jaguargpu nec ssem xavix
dsp16a konami nuon ssp1601 z180
dsp32c lc8670 nsc8105 superfx z8
dsp56k lh5801 patinho_feio t11 z80
e0c6200 lr35902 pdp1 tlcs870 z8000
esrip m146805 pdp8 tlcs90
f8 m37710 pic16c5x tlcs900
g65816 m4510 pic16c62x tms0980