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SNK Hyper Neo Geo 64

The Hyper Neo Geo 64 (1997) was SNK's attempt to move into 3D. A 64-bit cartridge system, it only ever hosted seven games (Samurai Shodown 64, Fatal Fury: Wild Ambition, Buriki One, Road's Edge…) before being dropped. Long one of the hardest platforms to emulate.

The Hyper Neo Geo 64 in its SNK metal case.
The Hyper Neo Geo 64 in its SNK metal case. Photo: Dogtoy, CC BY-SA 3.0, via Wikimedia Commons.

Identification

Field Value
Manufacturer SNK
Year 1997
Media cartridges (system BIOS + game cart)
Players 2
Screen orientation Horizontal
Main CPU NEC VR4300 (MIPS, 64-bit) @ 100 MHz

Architecture

Block Chip Role
Main CPU NEC VR4300 (MIPS III, 64-bit) @ 100 MHz game + 3D
Sound CPU NEC V53A (V33 + peripherals) drives the audio DSP
Sound DSP L7A1045 L6028 (SNK) 32-channel PCM, 44.1 kHz, up to 32 MB sample RAM
Microcontroller Toshiba TMP87PH40AN I/O / housekeeping
  • The VR4300 is the same family as the Nintendo 64's CPU — SNK aimed at real-time 3D (3D fighting, racing).
  • Audio runs through the V53A, which drives the L7A1045 DSP (large PCM sample bank).
  • Cartridge media: a shared system BIOS (hng64) plus one cartridge per game.

Notable games (nearly the whole catalogue)

Samurai Shodown 64 (1997), Samurai Shodown 64: Warriors Rage (1998), Fatal Fury: Wild Ambition (1998), Buriki One (1999), Road's Edge / Round Trip RV, Xtreme Rally / Off Beat Racer!, Beast Busters: Second Nightmare. The catalogue stayed very short — the platform was a commercial failure.

Common faults

Symptom Likely cause Lead
Won't boot BIOS cart / game cart / contacts Reseat, clean connectors
Silent/partial sound V53A / L7A1045 DSP Sound-stage diagnosis
Corrupted 3D custom video hardware Video diagnosis
Settings lost battery / EEPROM Reset / replace
No picture PSU, VR4300, harness 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 🟢: a cartridge system — the modern route is a multi-game cart / flashcart rather than reprogramming, where one exists for the platform → PCB preservation hub.
  • Scan rate 📺: not yet measured. The matching MAME driver does not expose its screen parameters in a form our extractor can use — no value is guessed here. Check what your monitor accepts before connecting → tri-sync and upscalers.
  • FPGA / emulation: see the Emulation & FPGA section below.

Repair (technician)

  • Custom 3D hardware: corrupt 3D = a custom video part (rare, donor) → test **video RAM
  • buffers** first.
  • VR4300 (MIPS) + V53A sound + L7A1045 DSP: silent sound = the DSP/V53A stage + sample ROMs.
  • Cartridges: oxidised contacts → clean.
  • Capacitors: recap PSU + audio filtering (a relatively recent board, possible SMD electrolytics).

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

DIP settings ✅

2 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 hng64
Setting Position Options (default in bold)
IN0 — Off · On
IN1 — Off · On
IN2 — Off · On
IN3 — Off · On
IN4 — Off · On
IN5 — Off · On
IN6 — Off · On
IN7 — Off · On
DIP settings — MAME set hng64_shoot
Setting Position Options (default in bold)
DEBUG — 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. There is no measurement table for this platform — MAME's sources yield nothing usable for it. Any frequency quoted under Architecture on this page serves as a marker; otherwise compare against a working board rather than against a number: an invented value condemns healthy parts. → PCB diagnosis

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 (snk/hng64.cpp). Long very incomplete (rough 3D and sound), support has improved markedly of late — notably sound (proper V53A emulation) around modern MAME releases.
  • FPGA / MiSTer: no core (64-bit 3D hardware too complex) → MAME.

The Hyper Neo Geo 64 3D is also covered on the restoration/conversion side: SNK Hyper 64 converts.

Lineage

Follows the Neo-Geo MVS (2D) as SNK's 3D attempt. Contemporary of Sega Model 2/3 and Namco System 22/23, but far less widespread.

Photos / assets

(To add: HNG64 BIOS board, game cartridge, L7A1045 DSP.)

Sources & attribution

Image:

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.