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Namco ND-1

A small 1995 Namco platform, overshadowed by the System 11 and 22 — but notable for one thing: everything on it comes from a single crystal. The 68000, the MCU and the sound chip are three divisions of the same 49.152 MHz. Which is exactly what a technician wants to know.

Identification

Field Value
Manufacturer Namco
Years 1995-1996
Main CPU M68000 @ 12.288 MHz (49.152 ÷ 4)
MCU Hitachi H8/3002 (HD6413002F16, QFP100) @ 16.384 MHz (49.152 ÷ 3)
Sound Namco C352 — 32-voice, 4-channel PCM (QFP100) @ 24.576 MHz (49.152 ÷ 2)
Master crystal 49.152 MHz — the only one
PCB format JAMMA

One crystal, three clocks

This is the platform's diagnostic point. 49.152 ÷ 2, ÷ 3 and ÷ 4 give the C352, the H8/3002 and the 68000 respectively.

The direct consequence: if all three clocks are wrong together, look at the master crystal — not at three chips. And if only one is wrong, it is that one's divider.

Expected clocks — measurement table ✅

Component Expected clock Role
M68000 12.288 MHz Main CPU
H8/3002 16.384 MHz MCU
C352 24.576 MHz PCM (sound)

The H8/3002 has no internal ROM

MAME says so, and it matters in repair: unlike many protection MCUs, this H8/3002 has no internal program memory. Its code therefore comes from the board — there is nothing unrecoverable locked inside it.

Notable games

Namco Classic Collection Vol. 1 (1995) · Namco Classic Collection Vol. 2 (1996) · Gynotai (1996).

A compilation platform

The Namco Classic Collection titles gather the house classics — Pac-Man, Galaga, Dig Dug, Xevious, Rally-X — reworked for 1995. An ND-1 board is therefore, in itself, an archive of Namco's golden age in a single case. → Namco — classic hardware

Common faults

Symptom Probable cause Next step
Nothing starts, no clocks at all 49.152 MHz master crystal All three clocks derive from it: only one possible cause
One clock wrong the matching divider (÷2, ÷3 or ÷4) The crystal is fine if the other two are
No sound C352 or its 24.576 MHz clock Namco custom — no common replacement
Erratic behaviour H8/3002 or its code on the board The MCU has no internal ROM: the code reads off the board
No picture 68000 or the video stage PCB diagnosis

Repair (technician)

  • Start with the master crystal. On this board a general clock failure has one possible explanation. That is a shortcut few platforms offer.
  • The C352 is a Namco custom: no replacement, diagnose by comparison.
  • The H8/3002 can be replaced: with no internal ROM, a fresh part of the same model will do — which is not true of the usual protection MCUs.

→ Methods: PCB diagnosis · Recap

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 → 12,288 MHz (Main CPU)
  • H8/3002 → 16,384 MHz (MCU)
  • C352 → 24,576 MHz (PCM (sound))

No clock on the M68000 (12,288 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.

Modernisation & mods

  • No suicide: no battery-backed protection.
  • Scan rate 📺: ordinary JAMMA board.
  • ⚠️ Do not host ROMs — method only.

Emulation & FPGA

MAME covers the platform (namco/namcond1.cpp).

Photos / assets

(To take: the 49.152 MHz crystal and the three chips it feeds, the C352 and the H8/3002 in QFP100.)

What the Namco Classic Collection manuals establish ✅

Read off the images in the two manuals archived below — Vol.1 (Galaga, Xevious, Mappy) and Vol.2 (Pac-Man, Rally-X, Dig Dug). They follow the same template and differ only in the controls.

Item Vol.1 Vol.2
Lever 8-direction ×2 ⚠️ 4-direction ×2
Buttons 4 (2 per player) 2 (1 per player)
Start 2 2
Board 230 × 210 mm same
Monitor vertical same
Connection JAMMA + a 48-pin DDK 225D-10024C2-2312 extended edge connector same

Two switches on the board, and the second is little known

The manuals describe the option switches on the board itself:

  • No. 1 to ON → test mode
  • No. 2 to ON → Screen Freeze
  • "Normally, all of the option switches are OFF."

⚠️ A board that appears frozen on screen is not necessarily faulty: switch No. 2 may simply have been left ON.

⚠️ Two neighbouring pots, only one to touch: the manual points out the speaker volume control (counter-clockwise to reduce) and, right beside it, the brightness control — with the instruction "Do not use brightness volume".

The test menu offers nine screens: switch test, sound test, coin options, game options, object test, scroll test, A.D.S., color test and a cross-hatch pattern for monitor adjustment. Coin options go up to four separate mechanisms, with a common counter or one per slot, and a bonus coin setting.

Namco forbids the multimeter — a third generation, the same sentence

"Never test the PC boards for conductivity with a multimeter or similar device. The PCB contains sensitive chips which could be destroyed even by the internal voltage of such a device."

The same prohibition, near enough word for word, as on the System 11 and the System 12 — and, in Japanese this time, on the System 10 (Mr. Driller G). ⚠️ And it is not a Namco house rule: the Moon Cresta manual from Nichibutsu, older than any of these, carries the same prohibition with the same reason. ✅ Five manuals, two manufacturers — and it is the conductivity wording that recurs, the one that names the continuity test. ⓘ The Japanese manual gives the same reason as the English ones: it is the instrument's internal voltage that destroys the circuits.

Archived original documents ✅

Documents archived locally, found on Internet Archive on 13 August 2026 and identified from their title page. ⚠️ The items declare no licence.

Sources & attribution

Text (synthesised here; sources listed for attribution):

  • MAME — src/mame/namco/namcond1.cpp (BSD-3-Clause / GPL): the 49.152 MHz master crystal and its three divisions — 68000 at 49.152 ÷ 4, H8/3002 (HD6413002F16, QFP100) at 16.384 MHz = 49.152 ÷ 3, C352 (32-voice 4-channel PCM, QFP100) at 24.576 MHz = 49.152 ÷ 2 — together with the explicit note that the H8/3002 has no internal ROM capability — https://github.com/mamedev/mame/blob/master/src/mame/namco/namcond1.cpp

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.