Namco System 21

The Namco System 21, also known as the Polygonizer or Polygoniser, is an arcade system board unveiled by Namco in 1988 with the game Winning Run. It was the first arcade board specifically designed for 3D polygon processing. It was in development for over three years before release, since around the mid-1980s. The hardware went through significant evolution throughout its lifespan until the last games, Cyber Sled (1993) and Attack of the Zolgear (1994), were released. It was preceded by the Namco System 2 in 1987 and succeeded by the Namco System 22 in 1993.

System 21 games such as Galaxian³ and Starblade established Namco as the market leader in polygonal 3D video games up until the arrival of the Sega Model 1 in 1992. According to Phil Harrison (in the September 1989 issue of Commodore User), who visited Namco's Tokyo office, Atari's Hard Drivin' ran on an earlier, less powerful, version of this hardware, stating that Namco and Atari Games were sister companies at the time and that the System 21 was a shared development.

Overview
The Namco System 21 "Polygonizer" arcade board was the most powerful gaming hardware of the 1980s. Its 3D graphical capabilities would not be surpassed until the release of Sega's Model 1 arcade system in 1992.

The Namco System 21 consisted of four PCB's (printed circuit boards) in a metal casing and arguably features more graphics chips than any other gaming system to date. Of the four boards, the main one was the CPU board, which featured a multi-core 16/32-bit CPU design. The four main CPU processors provided a combined performance of nearly 10 MIPS (Million Instructions Per Second).

The most important board, however, was the 3D graphics board, which contained multiple graphics chips dedicated to 3D graphics; this was the first dedicated 3D graphics board and a precursor to the 3D graphics accelerator cards that later appeared for the PC-98 and PC platforms. The core GPU (Graphics Processing Unit) processors of the 3D graphics board were multiple dedicated DSP (Digital Signal Processing) graphics processors, dedicated to processing the complex 3D graphics for that time. In total, the CPU and DSP processors provided a combined performance far exceeding what other gaming systems were capable of up until the arrival of the Sega Model 1 in 1992.

Technical specifications
The System 21 arcade board consists of four PCB's housed in a metal crate, including the main CPU motherboard (similar to the Namco System 2 CPU board) and three GPU graphics/video boards: DSP board, 3D polygon board, and object framebuffer board.

Multiple System 21 arcade boards can be combined to provide greater power. Winning Run '91 uses a System 21B system, consisting of dual System 21 arcade boards.

Processors

 * Main CPU processors: 2× Motorola MC68000P12 (16/32-bit 68000) @ 12.288 MHz and Motorola 68020 (32-bit) @ 12.5 MHz
 * Fixed-point arithmetic: 16-bit & 32-bit instructions @ 8.089 MIPS (million instructions per second) (2× 68000 @ 4.301 MIPS, 68020 @ 3.788 MIPS )
 * DSP (used for performing 3D math) processors:
 * Original hardware: 5× Texas Instruments TMS320C20 @ 25 MHz
 * Fixed-point arithmetic: 16-bit & 32-bit instructions @ 62.5 MIPS (12.5 MIPS per DSP )
 * Floating-point arithmetic: 16-bit & 32-bit operations @ 641,026 FLOPS (floating-point operations per second) (128,205 FLOPS, or 7.8 microseconds per operation, per DSP )
 * Later hardware: 4× Texas Instruments TMS320C25
 * Sound CPU: Motorola M6809 @ 3.072 MHz (8-bit instructions @ 1.29 MIPS)
 * Sound chips:
 * Namco C140 @ 21.39 kHz: 24 PCM channels, stereo output
 * Yamaha YM2151 @ 3.57958 MHz: 8 FM synthesis channels
 * Yamaha YM3012 @ 3.57958 MHz: Floating point DAC, stereo output
 * MCU: Hitachi HD63705 @ 2.048 MHz (2.048 MIPS)
 * Additional CPU: 3× Zilog Z80 (8-bit & 16-bit instructions)
 * Namco Custom graphics chips: C195, 2× C197, C317, 4× C327, 4× C342, NB-1 sprite system, C355 Motion Object(B)
 * Other Namco Custom chips: Namco C68, C137 Clock Generator IC, C139 Serial I/F Controller, 2× C148 CPU Bus Manager, C149 Mouse/Trackball Decoder

Memory
RAM: 2370 KB (original hardware), or 2556 KB (later hardware)


 * Main RAM: 740 KB
 * CPU work RAM: 320 KB
 * High-speed SRAM: 212 KB (2× 8 KB, 2× 2 KB, 6× 32 KB )
 * Other CPU RAM: 420 KB (16 KB EEPROM, 256 KB C148, 64 KB unused, 4 KB DPRAM, 16 KB C139 SCI buffer, 64 KB shared)


 * Video RAM: 2120 KB (original hardware), or 2306 KB (later hardware)
 * CPU video RAM: 136 KB (original hardware), or 322 KB (later hardware)
 * Original hardware: 136 KB (64 KB polygon data, 8 KB DSP common RAM, 64 KB GPU common RAM)
 * Later hardware: 322 KB (64 KB DSP, 2 KB depth cue, 128 KB objects, 128 KB palette)
 * DSP RAM: 128 KB high-speed SRAM (2× 32 KB, 4× 8 KB, 16× 2 KB )
 * Main GPU video RAM: 1536 KB
 * High-speed 3D polygon/framebuffer SRAM: 490 KB (10× 32 KB, 4× 32 KB, 5× 2 KB, 4× 8 KB Mitsubishi M5M5178 )
 * Other GPU RAM: 320 KB (128 KB work RAM, 64 KB common RAM, 128 KB palette)


 * Audio RAM: 20 KB (8 KB main, 8 KB C140, 4 KB DPRAM)


 * MCU RAM: 2 KB DPRAM

Storage media: ROM board, Laserdisc

Graphics

 * Display resolution: 496×480 display (512×512 overscan), progressive scan
 * Color palette: 16,777,216 (24-bit RGB true color)
 * Colors on screen: 238,080 (32,768 unique colors, 8 depth cue intensity levels, 496×480 pixels)
 * Frame rate: 60 frames per second
 * Geometric performance: 60,000 polygons per second (1000 polygons per frame)
 * Graphical capabilities: Flat shading, depth cueing, Z-buffering, fog effects

Main CPU (Central Processing Unit) board

 * Main CPU processors:
 * System 21 & System 21B:
 * Main CPU processors: 2x Hitachi/Toshiba 68HC000 (16/32-bit Motorola 68000) @ 12.3 MHz each
 * Performance: 4.4 MIPS (Million Instructions Per Second) (2.2 MIPS each)
 * Additional CPU: 1-2 Motorola 68020 (32-bit) processors @ 12.3 MHz each
 * Instruction performance: 3.8 - 7.6 MIPS (3.8 MIPS each)
 * Floating-point performance: 95,000 FLOPS (Floating-point Operations Per Sec)
 * System 21C:
 * Main CPU processors: 1-9 Motorola 68020 (32-bit) processors @ 25 MHz each
 * Instruction performance: 7.6 - 69 MIPS (7.6 MIPS each)
 * Floating-point performance: 0.19 - 1.8 MFLOPS (Million Floating-point Operations Per Sec)
 * Additional CPU processors: 2-9 Motorola 68000 (16/32-bit) processors @ 12.3 MHz each
 * Performance: 4.4 - 20 MIPS (2.2 MIPS each)
 * Sound CPU:
 * System 21 & System 21B: Motorola MC68B09EP (based on 8/16-bit Motorola 6809) @ 3.1 MHz
 * Performance: 1.3 MIPS
 * Physical memory: 64 KB
 * System 21C: Motorola 68000 (32-bit) @ 12.3 MHz
 * Performance: 2.2 MIPS
 * MCU (Micro-Computer Unit) processor: Hitachi HD63705 (8-bit) @ 2.1 MHz
 * EPROM (Erasable Programmable Read-Only Memory) memory: 4 KB
 * FM synth (Frequency Modulation synthesis) sound chip: Yamaha YM2151 (OPM) @ 3.6 MHz
 * DAC (Digital-to-Analog Converter) sound chip for FM synth: Yamaha YM3012 (stereo)
 * PCM (Pulse-Code Modulation) sound chip: Namco C140 (24-channel, 21.4 KHz sampling rate)
 * DAC sound chip for PCM audio: Namco LC7880
 * XTAL: 3.6 MHz
 * OSC: 49.2 MHz
 * ROM (Read-Only Memory) voice memory: 16 MB (4x 4 MB modules)
 * RAM (Random Access Memory) chips: 2x MB8464, 2x MCM2018, 4x HM65256, 2x HM62256
 * Custom chips: 2x Namco 148, Namco C68, Namco 139, Namco 137, Namco 149
 * Other chips: Sharp PC900 & PC910 opto-oscillators, Hitachi HN58C65P (EEPROM), Fujitsu MB3771, 2x Fujitsu MB87077-SK, Sanyo LB1760, SYS87B-2B, CY7C132

DSP graphics board

 * GPU (Graphics Processing Unit) processors:
 * DSP (Digital Signal Processing) processors for performing 3D math:
 * System 21: 5x Texas Instruments TMS320C20 (32-bit) @ 25 MHz each
 * Performance: 62.5 MIPS (12.5 MIPS each)
 * System 21B: 4x Texas Instruments TMS320C25 (32-bit) @ 25 MHz each
 * Performance: 64 MIPS (16 MIPS each)
 * System 21C: 5-80 Texas Instruments TMS320C25 (32-bit) processors @ 25-40 MHz each
 * Performance: 80 MIPS (16 MIPS each) to 2048 MIPS (25.6 MIPS each)
 * Custom processors: 4x Namco 327, 4x Namco 342, 2x Namco 197, Namco 317, Namco 195
 * OSC: 40 MHz
 * Video RAM (VRAM) chips: 2x Hitachi HM62832, 4x Mitsubishi M5M5189, 16x ISSI IS61C68
 * ROM (Read-Only Memory) chip: Texas Instruments TMS27C04
 * Graphics display program ROM: GPR0L, GPR0U, GPR1L, GPR1U, GP0L, GP0U, GP1L, GP1U
 * Graphics display data ROM: GDT0L, GDT0U, GDT1L, GDT1U, GD0L, GD0U, GD1L, GD1U

Other boards

 * OSC for other two boards: 20 MHz and 38.8 MHz
 * Namco Custom GPU: C355 Motion Object (B)
 * 2D graphics: Namco NB-1 sprite system
 * Other Namco Custom chips: 187, 138, 165
 * RAM chips for other two boards: 10x HM62256, 4x 84256, 5x CY7C128, 4x M5M5178
 * Other chips: 16x 157, 2x L7A0564, MB8422-90LP, L7A0565 316, 150, 167
 * RAM: 3162 KB
 * Main RAM: 592 KB
 * Video RAM: 2544 KB (2304 KB GPU, 128 KB palette, 64 KB polygon data, 48 KB DSP)
 * DPRAM: 10 KB
 * Audio RAM: 16 KB
 * Display resolution: 496x480 to 512x512 per screen
 * Color palette: 16,777,216 colors (24-bit RGB)
 * Colors on screen: 262,144 (32,768 unique colors and 8 depth cue intensity levels)
 * Frame rate: 60 frames per second
 * Geometric performance: 46,140 quad polygons per second (769 quad polygons per frame)
 * Features: Flat shading, depth cueing, Z-buffering

Galaxian³ specifications
The Galaxian³ hardware, released in 1990, used multiple System 21 arcade boards. Galaxian³ uses sixteen System 21 boards, while its scaled-down successors Galaxian³: Project Dragoon and Attack of the Zolgear use two System 21 boards each. The upgraded specifications for Galaxian³ include:


 * Board composition: 5 CPU boards, 1 sound board, 16 video board sets (16 DSP boards, 16 3D polygon boards, 16 object framebuffer boards), 9 personal player-terminal boards


 * Main CPU: 5× Motorola 68020 @ 24.576 MHz (37.236 MIPS ), Motorola 68000 @ 12.288 MHz (2.15 MIPS ), 9× Motorola 68000 @ 12 MHz (18.9 MIPS )
 * Fixed-point arithmetic: 16-bit & 32-bit instructions @ 58.286 MIPS (million instructions per second)


 * DSP: 80× Texas Instruments TMS320C25 @ 40 MHz
 * Fixed-point arithmetic: 16-bit & 32-bit instructions @ 1600 MIPS (20 MIPS per DSP, 0.5 MIPS per MHz )
 * Floating-point arithmetic: 16-bit & 32-bit operations @ 16.41 MFLOPS (million floating-point operations per second) (205,128 FLOPS per DSP, 5128 FLOPS per MHz )


 * Sound CPU: Motorola 68000 @ 12 MHz (2.1 MIPS )
 * Sound chips: 4× Namco C140 @ 21.39 kHz
 * Audio capabilities: 96 PCM channels (24 per chip)
 * Speaker output: 4-channel Bose surround sound system


 * Display: 16-screen, 16× RGB projectors, 360-degree wrap-around
 * Resolution: 8064×504 (504×504 per screen) display, 8192×512 (512×512 per screen) overscan, progressive scan
 * Color palette: 16,777,216
 * Colors per screen: 254,016 (504×504)
 * Colors on display: 4,064,256 (254,016 per screen)
 * Frame rate: 60 frames per second
 * Geometric performance: 960,000 polygons per second (60,000 per screen)
 * Graphical capabilities: Flat shading, depth cueing, Z-buffering, fog effects


 * Storage media: ROM boards, 16 Laserdisc players (1 per screen)

List of System 21 games

 * Winning Run (1988)

System 21B

 * Winning Run Suzuka Grand Prix (1989)
 * Driver's Eyes (1990)
 * Winning Run 91 (1991) - 2× System 21 boards

System 21C

 * Galaxian³ (1990) - 16× System 21 boards
 * Solvalou (1991) - 3D sequel to Xevious (1982) and Super Xevious (1984)
 * Star Blade (1991)
 * Air Combat (1992)
 * ShimDrive (1992)
 * Cyber Sled (1993)
 * Galaxian³: Project Dragoon (1994) - 2× System 21 boards
 * Attack of the Zolgear (1994) - 2× System 21 boards