Early 3D boards

Every early 3D board has a general CPU and one or more DSPs or custom geometry chips. Each DSP runs its own program. The game logic usually runs on the main CPU. A port must reproduce the DSP programs too, so expect two or more instruction sets per game. Ghidra has no built-in module for most of these DSPs. Atari's Hard Drivin' is on the Atari page. Midway Zeus is on the Williams and Midway page.

Board	Years	Main CPU and clock	Sound	Refresh	Protection	MAME status	Ghidra
Namco System 21	1988 on	Two M68000 at 12.288 MHz	MC6809E	Not covered here	None listed	In MAME	68000 built in; none for the TMS320C25
Namco System 22, Super 22	1993 on	M68020 at 49.152 MHz / 2	C352 on an M37702 or M37710	Not covered here	None listed	2 of 42 not working	68000 built in; none for the DSPs
Sega Model 1	1992	NEC V60 at 16 MHz	68000 at 10 MHz, YM3438	Not covered here	Not covered here	TGP ROMs BAD_DUMP on four games	None for the V60
Sega Model 2	1993/1994	i960KB at 25 MHz	68000, SCSP	Not confirmed	315-5881, 315-5838	In MAME	Extension for the i960
Sega Model 3	1996	PowerPC 603ev, 66 to 166 MHz	68000, two SCSP	57.524 Hz (Supermodel)	315-5881	Known faults	PowerPC built in
Taito JC	1995	M68040 at 20 MHz	Not covered here	Not covered here	Not covered here	2 of 19 not working	68000 built in; none for the TMS320C51
Konami GTI Club, Hornet	1996, 1998	PowerPC 403GA at 32 MHz	68000 at 16 MHz	Not covered here	X76 secure EEPROM on some	58 of 72 Hornet entries not working	PowerPC built in; SHARC extension
Gaelco 3D	1996	M68000 at 15 MHz	ADSP-2115 at 16 MHz	Not covered here	Not covered here	1 of 20 not working	68000 built in

Namco System 21

Hardware

Namco System 21 "Polygonizer" (1988 onward) runs two M68000s at 12.288 MHz and an MC6809E for sound (MAME namcos21.cpp). The DSP setup varies by game.

• Winning Run and Driver's Eyes each use one TMS320C25.
• Cyber Sled and Star Blade use one master C67 plus four slave C67s. A C67 is a TMS320C25 with custom ROM.
• MAME clocks the C67s from a 40 MHz crystal (MAME namcos21_dsp_c67.cpp).

The master DSP parses the display list and applies high-level geometry. The slaves transform, project and clip each primitive's vertices.

Protection

None listed.

Tools

Ghidra and Unicorn cover the 68000. Neither has a TMS320 module. Use MAME to run the DSP programs.

Projects to learn from

None listed yet.

For an exact reimplementation

• Record which DSP setup the game uses: one TMS320C25 or five C67s.
• Reproduce the master and slave DSP programs as well as the 68000 code.

Namco System 22 and Super System 22

Hardware

System 22 (1993 onward) uses an M68020 at 49.152 MHz / 2 (MAME namcos22.cpp).

• The Super System 22 board notes list an MC68EC020FG25 at 24.576 MHz.
• The board has "two TI320C25 DSP (printed as C71)".
• The Prop Cycle test menu shows that the main CPU uploads code to the master DSP. The master uploads code to the slave.
• Sound and I/O run on a C74, a Mitsubishi M37702 MCU with mask ROM. Super System 22 uses an M37710 at 16.384 MHz with no internal ROM.
• Sound output is the Namco C352, a 32-channel PCM chip at 24.576 MHz.

Protection

None listed.

Tools

The first entries are Ridge Racer variants from 1993. Of 42 entries, 2 have MACHINE_NOT_WORKING. Ghidra has no built-in module for the TMS320C25 or the M37702.

Projects to learn from

Arcade Archives Ridge Racer (Namco, 1993, System 22) came out on 5 June 2025. It was the first Arcade Archives 2 title, on Switch 2, PS5 and Xbox Series X|S (Game Developer press release). Air Combat 22 followed on 3 July 2025. Rave Racer was announced for 26 February (VGC, Rave Racer).

For an exact reimplementation

• The uploaded DSP code exists only in RAM. Capture it from a running emulator.

Sega Model 1

Hardware

Model 1 (1992) runs an "NEC uPD70615GD-16-S V60 CPU, running at 16.000MHz" with a Fujitsu MB86233 "TGP" coprocessor. The header gives no TGP clock. Sound is a TMP68000N-10 at 10 MHz with a YM3438 at 8 MHz. The monitor runs at 24 kHz horizontal ("medium resolution") (MAME model1.cpp).

The games are Virtua Racing (1992), Virtua Fighter (1993), Tecwar/Netmerc (1993, Sega and Virtuality), Star Wars Arcade (1994) and Wing War (1994). Wikipedia puts Model 1 at 180,000 polygons per second and 6,500 per frame (Wikipedia, List of Sega arcade system boards).

Protection

Not covered here.

Tools

• The TGP program ROMs for Virtua Fighter (315-5724) are marked BAD_DUMP. So are those for Star Wars Arcade, Wing War and Netmerc (315-5711). The Virtua Racing TGP ROM (315-5573) is not.
• Virtua Fighter's collision is "significantly broken due to imperfect TGP RAM port emulation or hookup".
• No Ghidra module for the V60 is known (not confirmed). Unicorn has none.

Projects to learn from

M2 developed Sega Ages Virtua Racing for the Switch (Japan April 2019, other regions June 2019). It runs at 60 fps and up to 1080p. The arcade ran at 30 fps and 496 by 384 (Nintendo Life review). Whether that release emulates the Model 1 or reimplements it is not confirmed.

For an exact reimplementation

• For the games with BAD_DUMP TGP ROMs, do not use MAME as ground truth for the geometry stage.
• Plan for a V60 disassembler.
• The Model 1 TGP clock is unknown.

Sega Model 2

Hardware

MAME's header describes Model 2 (1993/1994; Daytona USA 1994) as "i960KB + (5x TGP) or (2x SHARC) or (2x TGPx4)" (MAME model2.cpp).

Variant	Main CPU	Geometry	Sound
Model 2	i960KB at 25 MHz	MB86234 TGPs at 50 MHz	Model 1 sound board
Model 2A-CRX	i960KB	MB86234	68000 at 45.1584 MHz / 4, SCSP at 45.1584 MHz / 2
Model 2B-CRX	i960KB	ADSP-21062 SHARCs at 32 MHz	As 2A
Model 2C-CRX	i960KB	MB86235 at 20 MHz	As 2A

MAME's video timing uses a 16 MHz pixel clock, 656 by 496 totals and 424 by 384 visible. The driver notes this may not be accurate. Wikipedia says co-development with GE Aerospace (Compu-Scene) began in September 1992, with 300,000 textured polygons per second at 60 fps (Wikipedia, List of Sega arcade system boards).

Protection

• A 315-5881 crypt device on the 2A, the 2B and Zero Gunner.
• A 315-5838 compression device, with a 317-0229 variant.
• Simulated PIC protection for "To The MAXX".
• A protection ROM overlay for GTX.

Tools

• ghidra_i960 adds the i960.
• ghidra-sharc targets the ADSP-214xx. The Model 2B uses the ADSP-21062.
• Ghidra has no module for the MB8623x TGPs.

Projects to learn from

None listed yet.

For an exact reimplementation

• Record the variant. The geometry processor and its instruction set depend on it.
• Do not rely on MAME's video timing.
• "To The MAXX" uses simulated protection in MAME. A port built on that simulation has the same errors.

Sega Model 3

Hardware

Model 3 (1996; Virtua Fighter 3 and Scud Race) uses a PowerPC 603ev (MAME model3.cpp).

• MAME's header lists "Step 1.0: 66 MHz PPC", "Step 1.5: 100 MHz PPC, faster 3D engine", "Step 2.0: 166 MHz PPC, even faster 3D engine" and "Step 2.1: 166 MHz PPC, same 3D engine as 2.0".
• A Guru readme in the same file says "The CPU on Scud Race runs at 66MHz". That conflicts with the Step 1.5 figure.
• The host bridge is a Motorola MPC105 or MPC106, depending on the step.
• The Real3D graphics have PCI IDs 0x16c311db (315-5827, Step 1.x) and 0x178611db (315-6022, Step 2). Both use Mitsubishi M5M410092FP 3D-RAM.
• Sound is a 68000-12 with two 315-5687 SCSP chips. The optional Digital Sound Board v1 has a Z80 at 4 MHz. The v2 board has a 68EC000 at 11 MHz.

Supermodel states that the Model 3 runs at "57.524 frames per second". It also states that Real3D, then a Lockheed Martin company, developed the graphics (Supermodel README).

Protection

Protection is a 315-5881 on a security board (171-7405B) with a 315-6050 Lattice ispLSI 2032. MAME maps it at 0xf01a0000.

Tools

• Supermodel emulates the Model 3 under the GPL on Windows, Linux and macOS.
• Ghidra's PowerPC module and Unicorn's PPC backend cover the main CPU (CPU families).
• Known MAME issues include "broken FPU values in matrices" in Magical Truck Adventure ("cpu core bug?") and texture faults in Spikeout.

Projects to learn from

Supermodel's source.

For an exact reimplementation

• Record the step of the board. The CPU clock and the 3D engine depend on it.
• Run the port at 57.524 Hz, Supermodel's figure.
• Check floating-point results against more than one emulator. MAME has a known FPU fault on one game.

Taito JC System

Hardware

Taito JC (1995) runs an M68040 at 20 MHz and a TMS320C51 DSP at 40 MHz. Games include Dangerous Curves and Landing Gear (both 1995) (MAME taitojc.cpp).

Protection

Not covered here.

Tools

Of 19 entries, 2 have MACHINE_NOT_WORKING. Most have IMPERFECT_GRAPHICS and IMPERFECT_TIMING.

Projects to learn from

None listed yet.

For an exact reimplementation

• MAME flags its timing as imperfect on most games. Do not rely on it.

Konami GTI Club and Hornet

Hardware

GTI Club (1996) and Hornet (1998) use a PowerPC 403GA at 32 MHz, a 68000 at 16 MHz for sound and up to two ADSP-21062 SHARCs at 36 MHz. Hornet games include Gradius IV (1998). GTI Club: Rally Cote D'Azur dates from 1996 (MAME gticlub.cpp; MAME hornet.cpp).

Protection

Some configurations use an X76 secure EEPROM.

Tools

• Of 72 Hornet entries, 58 have MACHINE_NOT_WORKING. Operation Thunder Hurricane (1997) does not work.
• Ghidra's PowerPC module covers the main CPU. ghidra-sharc targets the ADSP-214xx.

Projects to learn from

None listed yet.

For an exact reimplementation

• Most Hornet games do not run in MAME. Take ground truth from other emulators or from owned hardware.

Gaelco 3D

Hardware

Gaelco 3D (1996) runs an M68000 at 15 MHz on Speed Up, with an ADSP-2115 sound DSP at 16 MHz. Settings are stored in a 93C66 serial EEPROM (MAME gaelco3d.cpp).

Protection

Not covered here.

Tools

One of 20 entries does not work.

Projects to learn from

None listed yet.

For an exact reimplementation

• Load the 93C66 EEPROM image as an input to each test.

Sega Hikaru (1999) is not covered yet.