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Sega System C / C-2

The System C (1989) and its evolution System C-2 (1990) are Sega arcade boards built around the same VDP as the Mega Drive/Genesis (315-5313). A 68000, arcade dressing and colourful 2D: Columns, Bloxeed, the Puzzle & Action series (Tant-R/Ichidant-R) and above all Puyo Puyo.

PCB Sega System C-2

PCB Sega System C-2 — photo by Komatta, domaine public (Wikimedia Commons).

Identification

Field Value
Manufacturer Sega
Years System C (1989) · System C-2 (1990)
Connector type JAMMA
Players 2
Screen orientation Horizontal
CPU Motorola 68000 @ 10 MHz

Architecture

Block Chip Role
Main CPU Motorola 68000 (~10 MHz) game logic
Video Sega 315-5313 (Mega Drive VDP) tilemaps + sprites, dedicated colorizer
FM sound Yamaha YM3438 (YM2612-compatible) music
PSG SN76489 (built into the VDP) noise/square channels
Samples NEC µPD7759 C-2 only (voice/ADPCM samples)
I/O Sega 315-5296 inputs/outputs
  • The graphics core is the Mega Drive's (315-5313), but the board uses its own colorize chain (pixel data to a colorizer) instead of the VDP's standard RGB output — giving a wider palette than the console.
  • C vs C-2 difference: the System C-2 adds the µPD7759 (sample playback). Roughly, C = no µPD7759, C-2 = with it.

Notable games

  • System C: Columns, Columns II, Bloxeed, Tant-R (Puzzle & Action)…
  • System C-2: Puyo Puyo, Ichidant-R (Puzzle & Action 2), Borench, Thunder Force AC, Twin Squash, Ribbit!, the Print Club (Puri-Kura) series…

Security & protection

Many System C-2 games carry a protection chip from the 317-xxxx series (EPM5032 type). Per MAME, the protection is mostly understood: it relies on a table of 256 4-bit values unique to each game. It is named factually here; no key or bypass is provided.

Common faults

Symptom Likely cause Lead
Frozen screen / won't boot (C-2) 317-xxxx chip (protection) / customs Check; MAME documents the protection
Wrong colours 315-5313 VDP / colorizer Video diagnosis, reseat
Voice/samples silent (C-2) µPD7759 Sample-stage diagnosis
No music YM3438 / SN76489 FM/PSG-stage diagnosis
Settings lost DIP / battery Check DIP / replace battery
No picture PSU, 68000, JAMMA contacts Base diagnosis

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.

  • Battery 🟢: a save battery is fitted (settings/counters/RTC). A leaking battery corrodes traces — check and replace it before it leaks → 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 📺: the screen configuration lives in the Sega VDP device rather than the driver — not measured here. These VDPs output standard ~15 kHz: a 15 kHz chassis is fine. (Derived from the VDP family documented above, not computed from MAME.) → tri-sync and upscalers.
  • FPGA / emulation: see the Emulation & FPGA section below.

Repair (technician)

  • "Mega Drive in a cabinet" base: 315-5313 (Mega Drive VDP) + YM3438 → lots of repair overlap with a Mega Drive (VDP, colorizer, FM stage).
  • Protection: some games have a Sega protection chip → a crash = protection, not logic (donor / MAME).
  • 315-5296 I/O: dead controls = test that I/O custom + buffers.
  • Capacitors: recap PSU + audio filtering. Oxidised EPROM sockets: turned-pin socket.

→ 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
M68000 8.948862 MHz main CPU
YM3438 7.670454 MHz FM (sound)

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 ✅

28 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 anpanman
Setting Position Options (default in bold)
Demo Sounds SW2:1 On · Off
Demo Voice SW2:2 On · Off
DIP settings — MAME set bloxeedc
Setting Position Options (default in bold)
Credits to Start (VS) SW2:1 1 · 2 · 2 · 4
Credits to Start (Normal) SW2:2 1 · 2
Demo Sounds SW2:4 Off · On
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
High Speed Mode SW2:8 Off · On
DIP settings — MAME set bloxeedu
Setting Position Options (default in bold)
Credits to Start (Normal / VS) SW2:1,2 1 / 1 · 1 / 2 · 1 / 2 · 2 / 4
DIP settings — MAME set borench
Setting Position Options (default in bold)
Credits to Start SW2:1 1 · 2
Demo Sounds SW2:2 Off · On
Lives 1P Mode SW2:3,4 1 · 2 · 3 · 4
Lives 2P Mode SW2:5,6 2 · 3 · 4 · 5
Difficulty SW2:7,8 Easy · Medium · Hard · Hardest
DIP settings — MAME set columns
Setting Position Options (default in bold)
Demo Sounds SW2:2 Off · On
Difficulty SW2:5,6 Easiest · Easy · Normal · Hard
DIP settings — MAME set columns2
Setting Position Options (default in bold)
Cabinet SW2:1 Upright · Cocktail
Demo Sounds SW2:2 Off · On
VS. Mode Credits/Match SW2:3,4 1 · 2 · 3 · 4
Flash Mode Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
DIP settings — MAME set columnsu
Setting Position Options (default in bold)
Cabinet SW2:1 Upright · Cocktail
Demo Sounds SW2:2 Off · On
Background Music SW2:3 BGM #1 · BGM #2
Difficulty SW2:5,6 Easiest · Easy · Normal · Hard
DIP settings — MAME set headonch
Setting Position Options (default in bold)
Demo Sounds SW2:1 Off · On
Difficulty SW2:2,3 Easy · Medium · Hard · Hardest
Lives SW2:4,5 2 · 3 · 4 · 5
DIP settings — MAME set ichir
Setting Position Options (default in bold)
Demo Sounds SW2:1 Off · On
Difficulty SW2:2,3 Easy · Medium · Hard · Hardest
DIP settings — MAME set ooparts
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 · Medium · Hard · Hardest
Region SW2:6,7 Japan · USA · Export · Export
DIP settings — MAME set pclub
Setting Position Options (default in bold)
Coinage SW4:1,2,3 7C 1C · 6C 1C · 5C 1C · 4C 1C · 3C 1C · 2C 1C · 1C 1C · Free Play
Demo Sounds SW5:6 Off · On
DIP settings — MAME set pclubjv2
Setting Position Options (default in bold)
Coins per Credit (Normal / Alternate) SW4:1,2,3 25 / 30 · 6 / 7 · 10 / 12 · 1 / 2 · 3 / Free Play · 15 / 20 · 4 / 5 · 8 / 9
Alternate Coinage SW4:4 Off · On
Demo Sounds SW5:6 Off · On
DIP settings — MAME set potopoto
Setting Position Options (default in bold)
Credits to Start SW2:1 1 · 2
Demo Sounds SW2:2 Off · On
Coin Chute Type SW2:3 Common · Individual
Credits to Continue SW2:4 1 · 2
Buy-In SW2:5 No · Yes
Difficulty SW2:6,7 Easy · Medium · Hard · Hardest
Moving Seat SW2:8 No Use · In Use
DIP settings — MAME set puyo
Setting Position Options (default in bold)
Demo Sounds SW2:2 Off · On
VS. Mode Credits/Match SW2:3 1 · 3
1P Mode Difficulty SW2:4,5 Easy · Medium · Hard · Hardest
Moving Seat SW2:8 No Use · In Use
DIP settings — MAME set puyopuy2
Setting Position Options (default in bold)
Rannyu Off Button SW2:1 Use · No Use
Demo Sounds SW2:2 Off · On
Turn Direction SW2:3 1:Right 2:Left · 1:Left 2:Right
Difficulty SW2:4,5 Easy · Medium · Hard · Hardest
VS Mode Match/1 Play SW2:6,7 1 · 2 · 3 · 4
Battle Start credit SW2:8 1 · 2
DIP settings — MAME set ribbit
Setting Position Options (default in bold)
Credits to Start SW2:1 1 · 2
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 1 · 2 · 3 · 5
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
DIP settings — MAME set ribbitj
Setting Position Options (default in bold)
Credits to Start SW2:1 1 · 2
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 1 · 2 · 3 · 5
Difficulty SW2:5,6 Easy · Normal · Hard · Hardest
DIP settings — MAME set soniccar
Setting Position Options (default in bold)
Demo Sound Interval SW2:1,2 Off · Every 4 Minutes · Every 2 Minutes · On
Lighting Time SW2:3 Advertise & Playtime · Playtime Only
Light SW2:4 Off · On
Screen Display SW2:5 Insert 100-400 Yen · Insert Money
DIP settings — MAME set sonicfgt
Setting Position Options (default in bold)
Credit Mode SW2:1 Off · On
DIP settings — MAME set sonicpop
Setting Position Options (default in bold)
Demo Sounds SW2:1 On · Off
Trouble BGM SW2:2 On · Off
Region SW2:3,4 USA · Export · USA (duplicate) · Japan
Sensor Advertise SW2:5 On · Off
DIP settings — MAME set ssonicbr
Setting Position Options (default in bold)
Demo Sounds SW2:1 On · Off
Difficulty SW2:2,3 Easy · Medium · Hard · Hardest
DIP settings — MAME set stkclmns
Setting Position Options (default in bold)
Difficulty SW2:1,2 Easy · Medium · Hard · Hardest
Demo Sounds SW2:3 Off · On
Match Mode Price SW2:4 1 · 2
DIP settings — MAME set tfrceac
Setting Position Options (default in bold)
Credits to Start SW2:1 1 · 2
Demo Sounds SW2:2 Off · On
Lives SW2:3,4 2 · 3 · 4 · 5
Bonus Life SW2:5,6 10k, 70k, 150k · 20k, 100k, 200k · 40k, 150k, 300k · None
Difficulty SW2:7,8 Easy · Medium · Hard · Hardest
DIP settings — MAME set twinsqua
Setting Position Options (default in bold)
Credits to Start SW2:1 1 · 2
Demo Sounds SW2:2 Off · On
Buy In SW2:3 Off · On
Difficulty SW2:4,5 Easy · Medium · Hard · Hardest
Seat Type SW2:6 Normal · Moving
DIP settings — MAME set wwjumbo
Setting Position Options (default in bold)
Demo Sound Interval SW2:1,2 Off · Every 4 Minutes · Every 2 Minutes · On
Lighting Time SW2:3 Playtime Only · Advertise & Playtime
Light SW2:4 Off · On
Screen Display SW2:5 Insert 100-400 Yen · Insert Money
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 …
DIP settings — MAME set wwmarine
Setting Position Options (default in bold)
Demo Sound Interval SW2:1,2 Off · Every 3 Demo Cycles · Every 2 Demo Cycles · On
Capsule Mode SW2:3 Off · On
Credit Mode SW2:5 Off · On
DIP settings — MAME set wwpajero
Setting Position Options (default in bold)
Demo Sound Interval SW2:1,2 Off · Every 8 Demo Cycles · Every 4 Demo Cycles · On
DIP settings — MAME set zunkyou
Setting Position Options (default in bold)
Game Difficulty 1 SW2:1 Medium · Hard
Game Difficulty 2 SW2:2 Medium · Hard
Lives SW2:3,4 1 · 2 · 3 · 5
Demo Sounds SW2:5 Off · On

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

Procedure — a dead board, step by step ✅

What this adds

The general method lives in PCB diagnosis. This is its application to this platform: the same order, but with the values actually expected here, so you do not have to go back and forth.

Tools: multimeter, oscilloscope (or frequency counter), current-limited bench supply, desoldering braid. → Tooling

If the board is still in a cabinet

A CRT holds its charge with the machine unplugged. → CRT safety

1. Inspection, power off. Corrosion, cut tracks, oxidised EPROM legs, leaking SMD capacitors, dubious earlier repairs.

2. The connector, before anything else. A large share of "dead boards" are a contact problem, not a fault. Clean the contacts with isopropyl alcohol and reseat — not with an abrasive eraser on a gold edge, which takes the plating off and brings the problem back worse. It costs two minutes and settles the question.

3. Power, measured on the board. Aim for +5.0 V measured as close as possible to where power reaches the board — not at the PSU output: the drop is in the loom, and that is exactly what makes a board boot on the bench and not in the cabinet. Where you probe depends on this board's connector — JAMMA edge, JVS loom or a proprietary harness — plenty of makers kept one long after JAMMA arrived — see Identification above. → Wiring Check −5 V and +12 V too if the sound stage uses them. Suspected short: bring it up current-limited and find the hot spot.

4. /RESET. It must release after power-up. Held low = the CPU never starts. A 1–2 Hz loop is not the reset circuit, it is the watchdog: the CPU is crashing at boot, so look at the bus, not at the reset.

5. Clocks — the values expected on this platform.

  • M68000 → 8.948862 MHz (Main CPU)
  • YM3438 → 7.670454 MHz (FM (sound))

No clock on the M68000 (8.948862 MHz) and there is no point measuring anything else: the fault is the crystal, the divider, or the chip itself. That single measurement splits a dead board in two.

6. Bus. Activity on the main CPU's address lines tells you whether it is running or frozen. Frozen with good clocks and good reset → work RAM, bus buffers, ROMs.

7. It boots but the picture or the sound is wrong — that is another job: see Common faults on this page, then signal tracing.

Emulation & FPGA

  • Emulation: MAME (sega/segac2.cpp) — System C and C-2, 317-xxxx protection largely handled.
  • FPGA / MiSTer: no verified dedicated arcade core; the hardware nonetheless derives directly from the Mega Drive (MiSTer Genesis core on the console side).

EPROM repair

68000 program in 27C010 / 27C040 (MAME sega/segac2.cpp): Puyo Puyo = 4× 27C010 · Puyo Puyo 2 = 2× 27C040 · Tant R (Puzzle & Action) = 4× 27C040. ⚠ Some C-2 use a 317-xxxx (program encrypted, FD1094-like) → decrypted ROMs required.

Lineage

Derived directly from the Mega Drive (same 315-5313 VDP, same FM family) and a cousin of the System 18 on the Sega architecture side. It bridges Sega console hardware and early-1990s JAMMA 2D arcade.

Photos / assets

(To add: System C-2 board, 315-5313 VDP, 317-xxxx protection chip.)

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.