Namco — classic hardware (Pac-Man / Galaga / Dig Dug / Xevious)¶
Namco's golden age (1979-1983): Z80 tile + sprite boards that defined video games. Pac-Man (1980) and Galaga (1981) run on close but distinct bases; Dig Dug, Xevious, Mappy, Rally-X derive from them. Ultra-mature emulation and MiSTer cores available.
Identification¶
| Field | Value |
|---|---|
| Manufacturer | Namco (often distributed by Midway in the US) |
| Years | 1979-1983 |
| CPU | Zilog Z80 (1 to 3 depending on the board) |
| Sound | Namco WSG (Waveform Sound Generator, 3 voices) |
| Settings | DIP |
The two big families¶
| Base | CPU | Games |
|---|---|---|
| Pac-Man (1980) | 1× Z80 @ ~3.07 MHz + Namco WSG | Pac-Man, Ms. Pac-Man, Pac-Man Plus, Ponpoko… (and Sega's Pengo on a close base) |
| Galaga / Galaxian (1979-81) | 3× Z80 (Galaga) + custom star-field | Galaxian, Galaga, Xevious, Dig Dug, Bosconian… |
Typical architecture: background tiles + hardware sprites, a small palette, WSG waveform sound. The Galaxian/Galaga star-field is a dedicated hardware circuit (scrolling twinkling stars).
Notable games¶
Pac-Man (1980), Galaga (1981), Dig Dug (1982), Xevious (1983), Rally-X, Bosconian, Mappy, Super Pac-Man, Pac & Pal, Grobda…
DIP settings transcribed¶
Several of these games have their DIP tables already transcribed in-wiki: → DIP reference: Pac-Man, Galaga, Dig Dug….
Common faults¶
| Symptom | Likely cause | Lead |
|---|---|---|
| Corrupt sprites/tiles | video RAM, Z80 | RAM test, contacts |
| No / wrong sound | Namco WSG / amp | Sound-stage diagnosis |
| Missing stars (Galaga) | star-field circuit | Dedicated video diagnosis |
| Lost settings | DIPs misset | Check the DIP bank |
| No image | Power, Z80, harness | Base diagnosis |
Old boards → discrete TTL logic, frequent re-soldering and recap; many period bootlegs (mind the identification).
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 📺: ~16.0 kHz / 60.6 Hz — standard resolution, a classic 15 kHz chassis is fine → tri-sync and upscalers.
(Computed from the MAME sources —
namco/galaga.cpp— pixel clock ÷ htotal.) - FPGA / emulation: see the Emulation & FPGA section below.
Repair (technician)¶
- Discrete logic (late 70s-80s): diagnose TTL / static RAM / buffers, good/bad comparison. Namco WSG (sound) = a dedicated stage.
- Star-field custom (Galaxian/Galaga): missing/wrong star field = a dedicated generator circuit to diagnose on its own.
- 2716/2732 EPROMs + bipolar PROMs (addressing/colour): oxidised legs → re-tin / turned-pin socket; the colour/addressing PROMs are specific (don't confuse them).
- Edge contacts: clean; check the PSU.
→ 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 |
|---|---|---|
| Z80 | 3.072 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.
Archived original schematics ✅¶
Manufacturer schematics for games in this family, archived locally (so they do not depend on a third-party site staying up). They give the board's real functional breakdown: clock tree, address decoding, video stage, sound stage, power supply — exactly what you need to trace a missing signal back to its source.
- Dig Dug — full schematic (PDF)
Scope and limits
A schematic applies to the game and revision named. Within one family the general breakdown (buses, decoding, sound/video stages) carries over from board to board, but component references and custom chip pinouts do not transpose between titles. Use it as a map of the logic, not as a cross-reference table.
Source: the Arcade Game Manuals collection on the Internet Archive. Manufacturer documents with no explicit licence, kept here for preservation (machines out of service for over 25 years).
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.
Xevious — the Atari edition under Namco licence
All of them carried the same label here. Opened and identified from their title page on 13 August 2026.
| Doc | What the cover carries | Pages |
|---|---|---|
| TM-230 | Xevious — Operators Manual With Illustrated Parts Lists. The cover reads Trademark and © Namco 1982 | 72 |
| SP-230 | Schematic Package Supplement: main wiring, power supply, coin door wiring, memory map, CPU and video PCB schematics, and the Electrohome and Hantarex display schematics | 19 |
⚠️ Two monitors are covered by SP-230 — Electrohome and Hantarex. Check which one is in the cabinet before following a display sheet.
Atari codes read off the covers: TM = Operators Manual, SP = Schematic Package, a supplement to the manual.
→ Full catalogue: service manuals, wiring & game manuals
DIP settings ✅¶
9 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 bosco
| Setting | Position | Options (default in bold) |
|---|---|---|
| Difficulty | SWB:1,2 | Easy · Medium · Hardest · Auto |
| Allow Continue | SWB:3 | No · Yes |
| Demo Sounds | SWB:4 | Off · On |
| Freeze | SWB:5 | Off · On |
| Cabinet | SWB:8 | Upright · Cocktail |
| Coinage | SWA:1,2,3 | 4C 1C · 3C 1C · 2C 1C · 1C 1C · 2C 3C · 1C 2C · 1C 3C · Free Play |
| Bonus Fighter | SWA:4,5,6 | 15K and 50K Only · 20K and 70K Only · 10K, 50K, Every 50K · 15K, 50K, Every 50K · 15K, 70K, Every 70K · 20K, 70K, Every 70K · 30K, 100K, Every 100K · None · 30K, 100K, Every 100K · 30K, 120K, Every 120K … |
| Lives | SWA:7,8 | 1 · 2 · 3 · 5 |
DIP settings — MAME set boscomd
| Setting | Position | Options (default in bold) |
|---|---|---|
| 2 Credits Game | SWB:1 | 1 Player · 2 Players |
| Difficulty | SWB:2,3 | Easy · Medium · Hardest · Auto |
| Allow Continue | SWB:4 | No · Yes |
| Demo Sounds | SWB:5 | Off · On |
| Freeze | SWB:6 | Off · On |
DIP settings — MAME set digdug
| Setting | Position | Options (default in bold) |
|---|---|---|
| Coin B | SWA:1,2,3 | 3C 1C · 2C 1C · 1C 1C · 2C 3C · 1C 2C · 1C 3C · 1C 6C · 1C 7C |
| Bonus Life | SWA:4,5,6 | 10K, 40K, Every 40K · 10K, 50K, Every 50K · 20K, 60K, Every 60K · 20K, 70K, Every 70K · 10K and 40K Only · 20K and 60K Only · 10K Only · None · 20K, 60K, Every 60K · 30K, 80K, Every 80K … |
| Lives | SWA:7,8 | 1 · 2 · 3 · 5 |
| Coin A | SWB:1,2 | 2C 1C · 1C 1C · 2C 3C · 1C 2C |
| Freeze | SWB:3 | Off · On |
| Demo Sounds | SWB:4 | Off · On |
| Allow Continue | SWB:5 | No · Yes |
| Cabinet | SWB:6 | Upright · Cocktail |
| Difficulty | SWB:7,8 | Easy · Medium · Hard · Hardest |
DIP settings — MAME set galaga
| Setting | Position | Options (default in bold) |
|---|---|---|
| Difficulty | SWB:1,2 | Easy · Medium · Hard · Hardest |
| Demo Sounds | SWB:4 | Off · On |
| Freeze | SWB:5 | Off · On |
| Rack Test | SWB:6 | Off · On |
| Cabinet | SWB:8 | Upright · Cocktail |
| Coinage | SWA:1,2,3 | 4C 1C · 3C 1C · 2C 1C · 1C 1C · 2C 3C · 1C 2C · 1C 3C · Free Play |
| Bonus Life | SWA:4,5,6 | 20K, 60K, Every 60K · 20K and 60K Only · 20K, 70K, Every 70K · 20K, 80K, Every 80K · 30K and 80K Only · 30K, 100K, Every 100K · 30K, 120K, Every 120K · None · 30K, 100K, Every 100K · 30K and 150K Only … |
| Lives | SWA:7,8 | 2 · 3 · 4 · 5 |
DIP settings — MAME set galagamw
| Setting | Position | Options (default in bold) |
|---|---|---|
| 2 Credits Game | SWB:1 | 1 Player · 2 Players |
| Difficulty | SWB:2,3 | Easy · Medium · Hard · Hardest |
DIP settings — MAME set sxevious
| Setting | Position | Options (default in bold) |
|---|---|---|
| Coin B | SWB:3,4 | 1C 1C · 1C 2C · 1C 3C · 1C 6C |
| Freeze | SWB:8 | Off · On |
DIP settings — MAME set xevious
| Setting | Position | Options (default in bold) |
|---|---|---|
| Coin A | SWA:1,2 | 2C 1C · 1C 1C · 2C 3C · 1C 2C |
| Bonus Life | SWA:3,4,5 | 10K, 40K, Every 40K · 10K, 50K, Every 50K · 20K, 50K, Every 50K · 20K, 60K, Every 60K · 20K, 70K, Every 70K · 20K, 80K, Every 80K · 20K and 60K Only · None · 10K, 50K, Every 50K · 20K, 50K, Every 50K … |
| Lives | SWA:6,7 | 1 · 2 · 3 · 5 |
| Cabinet | SWA:8 | Upright · Cocktail |
| Flags Award Bonus Life | SWB:2 | No · Yes |
| Coin B | SWB:3,4 | 2C 1C · 1C 1C · 2C 3C · 1C 2C |
| Difficulty | SWB:6,7 | Easy · Normal · Hard · Hardest |
| Freeze | SWB:8 | Off · On |
DIP settings — MAME set xeviousa
| Setting | Position | Options (default in bold) |
|---|---|---|
| Coin B | SWB:3,4 | 1C 1C · 1C 2C · 1C 3C · 1C 6C |
| Copyright | SWB:8 | Namco · Atari/Namco |
DIP settings — MAME set xeviousb
| Setting | Position | Options (default in bold) |
|---|---|---|
| Copyright | SWB:8 | Namco · Atari/Namco |
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.
- Z80 → 3.072 MHz (Sound CPU (usually))
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 (
pacman.cpp,galaga.cpp,galaxian.cpp…) — among the best-preserved games in the world. - FPGA / MiSTer: cores available (Pac-Man, Galaga, Galaxian, Dig Dug…), a faithful hardware rebuild.
EPROM repair¶
Z80 program in small 2716 / 2732 EPROMs (2-4 KB). Ex. (MAME namco/galaga.cpp): Galaga / Xevious / Dig Dug / Bosconian = 4× 2732. + colour PROMs (82S123/129). Pac-Man ≈ 2716/2732.
Lineage¶
Precedes the System 1 (1987) then the System 2.
Photos / assets¶
(To add: Pac-Man board, Galaga board, Namco WSG, star-field circuit.)
Sources & attribution¶
- MAME —
pacman.cpp,galaga.cpp,galaxian.cpp(Z80, Namco WSG, star-field, games) — https://github.com/mamedev/mame - Wikipedia — Pac-Man / Galaga / Namco — CC-BY-SA — https://en.wikipedia.org/wiki/Namco
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.