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Sega System 16

Sega's flagship arcade platform (1985), successor to System 1/2. Shinobi, Golden Axe, Altered Beast, Fantasy Zone… Two major variants (16A and 16B) and a crucial point: many games use encrypted 68000 CPUs, including the FD1094s that "suicide" when their battery dies.

Identification

Field Value
Manufacturer Sega
Year 1985 (→ ~1990)
System / family System 16 (16A, 16B)
Connector type JAMMA
Players 2
Screen orientation Horizontal
CPU Motorola 68000 @ 10 MHz

Architecture

Block Chip Clock Role
Main CPU Motorola 68000 ~10 MHz often encrypted: FD1094 (68000 core + battery-backed SRAM key) or FD1089
Sound CPU Zilog Z80 ~4 MHz
Sound Yamaha YM2151 (FM) + NEC µPD7759 (ADPCM samples)
Video Sega customs (tilemaps + sprites) 320×224, multi-plane scrolling

FD1094 = 'suicide' risk

The FD1094 is a 68000 whose program is decrypted on the fly with a key stored in battery-backed SRAM. Dead battery = key lost = silent board. Most games' keys have been extracted/dumped by the community (recoverable), but you must reprogram the module. See also CPS-2 (same preservation logic).

Notable games: Shinobi (1987), Altered Beast (1988), Golden Axe (1989), Fantasy Zone, Alien Syndrome

System 16A vs 16B

Two hardware revisions (and sub-variants). The 16B is the most common; the layout, customs and ROM format differ.

Encryption & "suicide"

Sega protected many games with an encrypted 68000:

  • FD1094: encrypted 68000 whose key is in battery-backed SRAM. When the battery dies → key lost → dead game ("suicide"). It's Sega's suicide equivalent, earlier than the CPS-2. (Also used on System 18, X/Y-board, System 24.)
  • FD1089 (A/B): encrypted 68000 with a fixed key (in the chip) → no battery, no suicide.
  • Some games use an unencrypted 68000 (no issue).

Decryption & restoration (FD1094)

The FD1094 key (~8 KB) lives in the module's SRAM, on battery. The MAME team (Nicola Salmoria, Charles MacDonald…) extracted and archived most games' keys → several preservation routes:

  1. Extract the key from a living board (before the battery dies) and archive it — that's how the community saved most games.
  2. Re-inject an archived key into an FD1094 module (or a programmable substitute) to revive a suicided board.
  3. Decrypted ROMs + bare 68000: convert the board to run without the FD1094 (bypass), with the already-decrypted ROMs.

FD1089 games (fixed key) and unencrypted games don't have this problem.

Full FD1094/FD1089 guide: de-suicide, Arduino re-key, conversion

Common faults

Symptom Likely cause Lead
Dead FD1094 game Flat battery (suicide) Restore the key / decrypted ROMs; replace the battery
Shaky / unstable image Capacitors Recap
Corrupted graphics / sprites Customs, ROMs, contacts Reseat, cleaning
No sound Z80 / YM2151 Sound-stage diagnosis
No image Power, customs, JAMMA contacts Base diagnosis

Recap

Few electrolytic capacitors on these boards (sound/video stage) — targeted recap if the image is shaky / sound degraded / a cap leaks. The real issue remains the FD1094 battery (suicide). Kits: Console5 (arcade PCB).

Repair & conversion: ROM board, EPROM per socket

  • 4 System 16B ROM board types (171-5358 / 5521 / 5704 / 5797): a game is tied to its board type. Converting = swap the ROM board + protection chip.
  • Size → EPROM: 32 KB → 27C256 · 64 KB → 27C512 · 128 KB → 27C010 · 256 KB → 27C020. Program sockets A1-A8 (or IC1/IC2 on 171-5797).
  • Full game-by-game table (board + sockets + protection) and 317-xxxx keys: → EPROM / ROM board / de-suicide guide · Per-game key table

Conversions & mods

  • Decrypted ROMs (FD1094): free you from the battery.
  • Native RGB via JAMMA.
  • ⚠️ Do not host ROMs — method only.

Modernisation & mods

The common ground for every JAMMA board

Video, power, control panel and upscalers depend on the cabinet rather than the board: everything is centralised in Modernising a cabinet. To run the board outside a cabinet (at home, on a display): supergun.

  • Anti-suicide 🟠: some games/variants of this platform do suicide (battery-backed key) — see the dedicated section above to find out whether yours is affected. If so, the durable route is de-suicidingconversions and de-suiciding, not merely replacing the battery → save batteries.
  • Storage 🟡: the game lives in EPROM/mask ROM on the board. Changing or restoring a game means reprogramming the EPROMs (and, for a mask ROM, using a pinout adapter) → EPROM method.
  • Media preservation: replacing the original storage, multicarts, ODEs and modern options by family → PCB preservation hub.
  • Scan rate 📺: ~15.7 kHz / 60.0 Hz — standard resolution, a classic 15 kHz chassis is fine — the most common JAMMA case → tri-sync and upscalers. (Computed from the MAME sources — sega/segas16a.cpp + segas16b.cpp — pixel clock ÷ htotal.)
  • FPGA / emulation: see the Emulation & FPGA section below.

Repair (technician)

  • FD1094 / FD1089 = key in battery-backed SRAM: flat battery = suicide (dead game, healthy board, not a hardware fault). Replace the battery without cutting the key (piggyback); otherwise de-suicidebackup batteries.
  • Sega customs (tilemaps/sprites): corrupt = video RAM + buffers first, the custom next. Sound: Z80 + YM2151 + µPD7759.

Methods: PCB fault-finding · Recap · EPROM · Traces & vias

Expected clocks — measurement table ✅

Values extracted from the MAME sources for this platform. On a scope or frequency counter, a clock that is missing or off-value points straight at the crystal, the divider or the chip at fault — the fastest starting point on a dead board.

Component Expected clock Role
I8751 8 MHz protection MCU
M68000 10 MHz main CPU
YM2151 4 MHz FM (sound)
Z80 4 MHz · 5 MHz sound CPU (usually)

How to read this table

Several values for one component = several board variants in this family (or several instances of the chip clocked differently). These frequencies are those of the clock signal at the component's input, not of its original crystal — on many boards the clock is divided down from a single master crystal.

DIP settings ✅

39 games on this platform, settings extracted from the MAME sources (INPUT_PORTS_START blocks). The Position column gives the switch's physical reference on the board (SW2:!3,!4 = bank SW2, levers 3 and 4) — which is what lets you set it up without the paper manual. Games are sorted by MAME set name.

DIP settings — MAME set altbeast
Setting Position Options (default in bold)
Credits Needed SW2:1 1 Credit To Start · 2 Credit To Start
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 2 · 3 · 4 · Free Play
Player Meter SW2:5,6 2 · 3 · 4 · 5
Difficulty SW2:7,8 Easy · Normal · Hard · Hardest
DIP settings — MAME set atomicp
Setting Position Options (default in bold)
Coin B SW1:1,2,3 4C 1C · 3C 1C · 2C 1C · 1C 1C · 1C 2C · 1C 3C · 1C 4C · 1C 5C
Coin A SW1:4,5,6 4C 1C · 3C 1C · 2C 1C · 1C 1C · 1C 2C · 1C 3C · 1C 4C · 1C 5C
Lives SW1:7,8 1 · 2 · 3 · 5
Difficulty SW2:1,2 Easy · Normal · Hard · Hardest
Level Select SW2:3 Off · On
Flip Screen SW2:4 Off · On
Demo Sounds SW2:5 Off · On
Allow Continue SW2:6 No · Yes
Game Mode SW2:7 Normal Tetris · Atomic Point
DIP settings — MAME set aurail
Setting Position Options (default in bold)
Cabinet SW2:1 Upright · Cocktail
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 2 · 3 · 4 · 5
Bonus Life SW2:5 80K/200K/500K/1000K · 100K/300K/700K/1000K
Difficulty SW2:6 Normal · Hard
Controller SW2:7 1 Player Side · 2 Players Side
Special Function Mode SW2:8 Off · On
DIP settings — MAME set bayroute
Setting Position Options (default in bold)
Allow Continue SW2:1 Off · On
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 1 · 3 · 5 · Free Play
Bonus Life SW2:5,6 100k · 150k · 200k · None
Difficulty SW2:7,8 Easy · Normal · Hard · Hardest
DIP settings — MAME set bullet
Setting Position Options (default in bold)
Players SW2:1 2 · 3
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 2 · 3 · 4 · 5
DIP settings — MAME set cencourt
Setting Position Options (default in bold)
Debug Display SW2:1 Off · On
DIP settings — MAME set cotton
Setting Position Options (default in bold)
Demo Sounds SW2:1 Off · On
Lives SW2:2,3 2 · 3 · 4 · 5
Difficulty SW2:4,5 Easy · Normal · Hard · Hardest
DIP settings — MAME set dddoor
Setting Position Options (default in bold)
Advertising Interval SW2:1,2 30 Seconds · 1 Minute · 3 Minutes · 5 Minutes
Coinage SW1:1,2,3,4 4C 1C · 3C 1C · 2C 1C · 1C 1C · 1C 1C · 1C 1C · 1C 1C · 1C 1C · 1C 1C · 1C 1C …
Large Prize Discharge Rate SW1:6,7,8 14% · 16% · 18% · 20% · 22% · 24% · 26% · 50%
DIP settings — MAME set ddux
Setting Position Options (default in bold)
Demo Sounds SW2:1 Off · On
Difficulty SW2:2,3 Easy · Normal · Hard · Hardest
Lives SW2:4,5 2 · 3 · 4 · 5
Bonus Life SW2:6,7 150k · 200k · 300k · 400k
DIP settings — MAME set dfjail
Setting Position Options (default in bold)
Coinage SW1:1,2,3,4 8C 1C · 7C 1C · 6C 1C · 5C 1C · 4C 1C · 3C 1C · 2C 1C · 1C 1C · 1C 2C · 1C 3C …
Lives SW1:5,6,7 1 · 2 · 3 · 4 · 5 · 6 · 7 · 8
Difficulty SW2:1,2 Easy · Normal · Hard · Hardest
Demo Sounds SW2:3 Off · On
Flip Screen SW2:4 Off · On
DIP settings — MAME set dunkshot
Setting Position Options (default in bold)
Winner Advances SW2:1 Off · On
Demo Sounds SW2:2 Off · On
VS Time SW2:3,4 2P 1:30/ 3P 2:00/ 4P 2:30 · 2P 2:00/ 3P 2:30/ 4P 3:00 · 2P 2:30/ 3P 3:00/ 4P 3:30 · 2P 3:00/ 3P 3:30/ 4P 4:00
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
CPU Starts With +6 Pts. SW2:7 Off · On
Allow Continue SW2:8 Off · On
DIP settings — MAME set eswat
Setting Position Options (default in bold)
Credits To Start SW2:1 1 Credit · 2 Credits
Demo Sounds SW2:2 Off · On
Flip Screen SW2:3 Off · On
Timer SW2:4 Normal · Hard
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
Lives SW2:7,8 1 · 2 · 3 · 4
DIP settings — MAME set exctleag
Setting Position Options (default in bold)
Demo Sounds SW2:1 Off · On
Starting Points SW2:2,3,4 2000 · 3000 · 4000 · 5000 · 6000 · 7000 · 8000 · 9000
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
Point Table SW2:7,8 Easy · Normal · Hard · Hardest
DIP settings — MAME set fantzoneta
Setting Position Options (default in bold)
Cabinet SW2:1 Upright · Cocktail
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 2 · 3 · 4 · 240 (Cheat)
Extra Ship Cost SW2:5,6 5000 · 10000 · 15000 · 20000
Difficulty SW2:7,8 Easy · Normal · Hard · Hardest
DIP settings — MAME set fpoint
Setting Position Options (default in bold)
Demo Sounds SW2:2 Off · On
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
Clear Round Allowed SW2:7 1 · 2
2 Cell Move SW2:8 No · Yes
DIP settings — MAME set fpointbl
Setting Position Options (default in bold)
Demo Sounds SW2:2 Off · On
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
Clear Round Allowed SW2:7 1 · 2
2 Cell Move SW2:8 No · Yes
Coin A SW1:1,2,3,4 4C 1C · 3C 1C · 2C 1C · 2 Coins/1 Credit 5/3 6/4 · 2 Coins/1 Credit 4/3 · 1C 1C · 1 Coin/1 Credit 2/3 · 1 Coin/1 Credit 4/5 · 1 Coin/1 Credit 5/6 · 2C 3C …
Coin B SW1:5,6,7,8 4C 1C · 3C 1C · 2C 1C · 2 Coins/1 Credit 5/3 6/4 · 2 Coins/1 Credit 4/3 · 1C 1C · 1 Coin/1 Credit 2/3 · 1 Coin/1 Credit 4/5 · 1 Coin/1 Credit 5/6 · 2C 3C …
DIP settings — MAME set fz2
Setting Position Options (default in bold)
Lives SW2:3,4 2 · 3 · 4 · 240 (Cheat)
Difficulty SW2:7,8 Easy · Normal · Hard · Hardest
DIP settings — MAME set goldnaxe
Setting Position Options (default in bold)
Credits Needed SW2:1 1 Credit To Start · 2 Credits To Start
Demo Sounds SW2:2 Off · On
Difficulty SW2:3,4,5,6 Special · Easiest · Easier · Easy · Normal · Hard · Harder · Hardest
DIP settings — MAME set hwchamp
Setting Position Options (default in bold)
Demo Sounds SW2:2 Off · On
Start Level Select SW2:3 Off · On
Allow Continue SW2:4 No · Yes
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
Time Adjust SW2:7,8 Easy · Normal · Hard · Hardest
DIP settings — MAME set lockonph
Setting Position Options (default in bold)
Coin A SW0:1,2,3 4C 1C · 3C 1C · 2C 1C · 1C 1C · 1C 2C · 1C 3C · 1C 4C · 1C 5C
Coin B SW0:4,5,6 4C 1C · 3C 1C · 2C 1C · 1C 1C · 1C 2C · 1C 3C · 1C 4C · 1C 5C
Flip Screen SW0:8 Off · On
Difficulty SW1:1,2,3 0 · 1 · 2 · 3 · 4 · 5 · 6 · 7
Allow Continue SW1:4 No · Yes
Region SW1:5 Korea · Europe
DIP settings — MAME set mvp
Setting Position Options (default in bold)
Credits To Start SW2:1 1 Credit · 2 Credits
Demo Sounds SW2:2 Off · On
Innings SW2:3 1 Credit 1 Inning · 2 Credits 3 Innings
Time Limits SW2:4,5,6 1 Normal · 2 · 3 · 4 · 5 · 6 · 7 · 8 Hardest
Difficulty SW2:7,8 Easy · Hard · Normal · Hardest
DIP settings — MAME set passsht
Setting Position Options (default in bold)
Demo Sounds SW2:1 Off · On
Initial Point SW2:2,3,4 2000 · 3000 · 4000 · 5000 · 6000 · 7000 · 8000 · 9000
Point Table SW2:5,6 Easy · Normal · Hard · Hardest
Difficulty SW2:7,8 Easy · Normal · Hard · Hardest
DIP settings — MAME set passshtj
Setting Position Options (default in bold)
Demo Sounds SW2:1 Off · On
Initial Point SW2:2,3,4 2000 · 3000 · 4000 · 5000 · 6000 · 7000 · 8000 · 9000
Point Table SW2:5,6 Easy · Normal · Hard · Hardest
Difficulty SW2:7,8 Easy · Normal · Hard · Hardest
DIP settings — MAME set riotcity
Setting Position Options (default in bold)
2 Credits to Start SW2:1 Off · On
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 1 · 2 · 3 · 4
Bonus Life SW2:5,6 Easy · Normal · Hard · Hardest
Difficulty SW2:7 Normal · Hard
Attack Button to Start SW2:8 Off · On
DIP settings — MAME set ryukyu
Setting Position Options (default in bold)
Demo Sounds SW2:1 Off · On
Cancel per Credit SW2:2 2 · 3
Timer Speed SW2:3 20 seconds · 30 seconds
PCM Voice SW2:4 Off · On
Omikuji Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
Difficulty SW2:7,8 Easy · Normal · Hard · Hardest
DIP settings — MAME set sdi
Setting Position Options (default in bold)
Allow Continue SW2:1 Off · On
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 2 · 3 · 4 · Free
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
Bonus Life SW2:7,8 Every 50000 · 50000 · 100000 · None
DIP settings — MAME set shinobi
Setting Position Options (default in bold)
Cabinet SW2:1 Upright · Cocktail
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 2 · 3 · 5 · Free Play
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
Enemy's Bullet Speed SW2:7 Slow · Fast
Language SW2:8 Japanese · English
DIP settings — MAME set sjryuko
Setting Position Options (default in bold)
Coin A SW1:1,2,3,4 4C 1C · 3C 1C · 2C 1C · 1C 1C · 1 Coin/1 Credit · 2C 3C · 1C 2C · 1C 3C · 1C 4C · 1C 5C …
Coin B SW1:5,6,7,8 4C 1C · 3C 1C · 2C 1C · 1C 1C · 1 Coin/1 Credit · 2C 3C · 1C 2C · 1C 3C · 1C 4C · 1C 5C …
CPU Level SW2:1,2 Weak · Medium Weak · Medium Strong · Strong
Demo Sounds SW2:3 Off · On
DIP settings — MAME set snapper
Setting Position Options (default in bold)
Coin B SW0:1,2,3 4C 1C · 3C 1C · 2C 1C · 1C 1C · 1C 2C · 1C 3C · 1C 4C · 1C 5C
Coin A SW0:4,5,6 4C 1C · 3C 1C · 2C 1C · 1C 1C · 1C 2C · 1C 3C · 1C 4C · 1C 5C
Lives SW0:7,8 1 · 2 · 3 · 5
Demo Sounds SW1:5 Off · On
DIP settings — MAME set sonicbom
Setting Position Options (default in bold)
Difficulty SW2:1,2,3 Easy · Normal · Hard 1 · Hard 2 · Hard 3 · Hard 4 · Hard 5 · Hardest
Lives SW2:4,5 2 · 3 · 4 · 5
Bonus Life SW2:6,7 30k · 40k · 50k · 80k
Cabinet SW2:8 Upright · Cocktail
DIP settings — MAME set tetris
Setting Position Options (default in bold)
Demo Sounds SW2:2 Off · On
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
DIP settings — MAME set timescan
Setting Position Options (default in bold)
Flip Screen SWE:1 Off · On
Out Lane Pin SWE:2 Near · Far
Special SWE:3,4 3 Credits · 2 Credits · 1 Credit · 2000000 Points
Allow Continue SWE:5 No · Yes
Cabinet SW2:1 Upright · Cocktail
Extended Score SW2:2,3,4,5 Credit 1000000/2000000 · Credit 1200000/2500000 · Credit 1500000/3000000 · Credit 2000000/4000000 · Credit 1000000 · Credit 1200000 · Credit 1500000 · Credit 1800000 · Ball 100000 · Ball 200000 …
Number Match SW2:6 No · Yes
Pin Rebound SW2:7 Well · A Little
Lives SW2:8 3 · 5
DIP settings — MAME set toryumon
Setting Position Options (default in bold)
Demo Sounds SW2:1 Off · On
VS Play Mode SW2:5 1 Set · 3 Set
Difficulty SW2:6,7,8 Easy · Normal · Hard · Hard+1 · Hard+2 · Hard+3 · Hard+4 · Hard+5
DIP settings — MAME set tturf
Setting Position Options (default in bold)
Continues SW2:1,2 None · 3 · Unlimited · Unlimited
Difficulty SW2:3,4 Easy · Normal · Hard · Hardest
Starting Energy SW2:5,6 3 · 4 · 6 · 8
Demo Sounds SW2:7 Off · On
Bonus Energy SW2:8 1 · 2
DIP settings — MAME set ultracin
Setting Position Options (default in bold)
Advertise Sound Interval SW2:1,2 Off · No Interval · 4 Cycle · 2 Cycle
Advertise Coin Indication SW2:3 Coin · 100 - 400 Yen
Game Time SW2:4 Short · Normal
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
DIP settings — MAME set wb3
Setting Position Options (default in bold)
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 2 · 3 · 4 · 5
Bonus Life SW2:5 50k/100k/180k/300k · 50k/150k/300k
Difficulty SW2:6 Normal · Hard
Test Mode SW2:7 No · Yes
DIP settings — MAME set wfishing
Setting Position Options (default in bold)
Coinage SW1:1,2,3,4 4C 1C · 3C 1C · 2C 1C · 1C 1C · Free Play · 1C 1C · 1C 1C · 1C 1C · 1C 1C · 1C 1C …
Demo Sounds SW2:1 On · Off
Advertise Coin Indication SW2:3 100-400 Yen · Coin
DIP settings — MAME set wrestwar
Setting Position Options (default in bold)
Demo Sounds SW2:2 Off · On
Round Time SW2:3,4 100 · 110 · 120 · 130
Allow Continue SW2:6 No · Yes
Difficulty SW2:7,8 Easy · Normal · Hard · Hardest
DIP settings — MAME set wwthomas
Setting Position Options (default in bold)
Coinage SW1:1,2,3,4 4C 1C · 3C 1C · 2C 1C · 2C 1C · 2C 1C · 2C 1C · 2C 1C · 2C 1C · 2C 1C · 2C 1C …
Advertise Sound Interval SW2:1,2 Off · No Interval · 4 Cycle · 2 Cycle
Advertise Coin Indication SW2:3 Coin · 100 - 400 Yen
Card Holding Time SW2:4 Normal · Long

Check against your own board

These settings apply to the game and revision described by MAME. One title may have several DIP sets depending on region or revision, and some systems use soft-dips (settings in memory, via the test menu) rather than physical switches. In case of a discrepancy, the board's silkscreen and the test menu are authoritative.

See also: DIP reference · game manuals

Emulation & FPGA

  • MAME: System 16A/B emulated, including FD1094/FD1089 decryption via extracted keys.
  • FPGA / MiSTer: the jts16 core (Jotego) — System 16A/B in rebuilt logic (unencrypted games and titles whose FD1094 key is known).

Photos / assets

(To add: 16B board, FD1094 module + battery, customs.)

Sources & attribution

Review & corrections

How this space is used

Spotted a wrong value, an outdated procedure, a chip reference that does not match your board? Say so here, with what you observed (model, board revision, serial number, measurement). Every report is cross-checked against a source before anything changes — an unverifiable correction is published as “reported by …, not cross-checked” rather than silently applied.

Reading is open to everyone; posting requires signing in with Discord. Reports from the wiki's declared reviewers are handled first; anyone else's are read too, but go through a human before anything is changed.