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Namco System 23 (Gorgon / Super System 23)

Namco's last in-house-designed arcade hardware (1997): an evolved textured 3D with a MIPS R4650 CPU, in Gorgon (22.5), System 23 and Super System 23 variants. Time Crisis 2, Final Furlong, 500 GP… After it, Namco moved to the PS1 (System 10/11/12).

Identification

Field Value
Manufacturer Namco
Years announced 1996, released 1997
Type textured 3D (multi-board crate), Namco's last custom design
Variants Gorgon / System 22.5 · System 23 · Super System 23 (+ Evolution 2)
Cabinets often cockpit / motion / gun

Architecture

Block Chip Role
CPU (Gorgon) NKK NR4650 @ 133 MHz (MIPS) game
CPU (System 23) IDT R4650 @ 133 MHz (64-bit MIPS) game
CPU (Super 23) R4650 @ 166 MHz (Evolution 2: 200 MHz) game
Sound CPU Hitachi H8/3002 @ 16.93 MHz drives the sound
Sound Namco C352 32 PCM voices (like System 22)
I/O Hitachi H8/3334 (Gorgon/23) → PIC16Cxx (Super 23) controls
GPU custom Namco (texture mapping) evolution of the System 22

Gorgon (aka "System 22.5") is the bridge between 22 and 23 (Final Furlong, Rapid River). The System 23 then Super System 23 raise the CPU clock and effects. Emulated in MAME (namco/namcos23.cpp).

Notable games

  • Gorgon (22.5): Final Furlong (1997), Rapid River.
  • System 23: Time Crisis 2 (1997), Downhill Bikers, Motocross Go!.
  • Super System 23: GP500, 500 GP, Crisis Zone, Guitar Jam, Angler King.

Common faults

Symptom Likely cause Lead
No 3D / corrupt textures custom GPU / texture RAM Board-by-board crate diagnosis
Random freeze R4650 / shared RAM CPU diagnosis, RAM test
No/partial sound C352 / sound H8 Sound-stage diagnosis
Controls / gun dead I/O H8/PIC / harness I/O diagnosis
Cabinet motion dead motion board / actuators Mechanical diagnosis

A multi-board crate + rare customs → methodical 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.

  • 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 📺: ~31.45 kHz / 59.9 Hz — high resolution (VGA class), ⚠️ a 31 kHz / tri-sync monitor is required; a 15 kHz chassis is incompatible → tri-sync and upscalers. (Computed from the MAME sources — namco/namcos23.cpp — pixel clock ÷ htotal.)
  • FPGA / emulation: see the Emulation & FPGA section below.

Repair (technician)

  • Namco's last custom design (multi-board crate, R4650 MIPS): diagnose board by board; 3D customs are rare (donor), a hard platform to source.
  • H8/3002 sound CPU: silent sound = H8 / sound ROM / DAC.
  • Capacitors: recap (likely SMD electrolytics). Inter-board contacts: care.

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

Original manuals for games on this platform ✅

Manufacturer manuals for games running on this board. Beyond the instructions, they very often carry the full DIP settings, the connector pinout, the test procedure, the parts list and the expected voltages.

→ Full catalogue: service manuals, wiring & game manuals

DIP settings ✅

5 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 gmen
Setting Position Options (default in bold)
SH-2 DIP Bit 0 — Off · On
SH-2 DIP Bit 1 — Off · On
SH-2 DIP Bit 2 — Off · On
SH-2 DIP Bit 3 — Off · On
SH-2 DIP Bit 4 — Off · On
SH-2 DIP Bit 5 — Off · On
SH-2 DIP Bit 6 — Off · On
SH-2 DIP Bit 7 — Off · On
DIP settings — MAME set gorgon
Setting Position Options (default in bold)
Service Mode DIP DIP:1 Off · On
DIP settings — MAME set raceon
Setting Position Options (default in bold)
Activate Wheel Test DIP:4 On · Off
DIP settings — MAME set rapidrvrp
Setting Position Options (default in bold)
Debug Messages DIP:5 Off · On
Dev Service Mode DIP:2 Off · On
User Service Mode DIP:1 Off · On
DIP settings — MAME set s23
Setting Position Options (default in bold)
Service Mode DIP DIP:8 Off · On
Skip POST DIP:7 Off · On
Freeze? DIP:6 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

Emulation & FPGA

  • Emulation: MAME (namco/namcos23.cpp).
  • FPGA / MiSTer: no core (multi-board textured 3D, out of budget).

Lineage

After the System 22 (1993). Namco's last custom design: the firm then adopted the PlayStation (System 10/11/12, to document) and later the System 246/256 (PS2).

Photos / assets

(To add: System 23 crate, R4650, C352, I/O board.)

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.

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