Repair & Schematics
Sega NAOMI 2

Hardware Overview (Sega NAOMI 2)

4min

The Sega NAOMI 2 is an arcade board developed by Sega and is a successor to Sega NAOMI hardware. It was originally released in 2000. Since it uses similar NAOMI architecture (but significantly beefed up), it is also fully backwards compatible with its predecessor. The NAOMI 2 is significantly more powerful than the NAOMI, including a dual CPU setup, new T&L GPU, dual rasterizer GPU, increased memory, and faster bandwidth. This leads to games with much more polygons than a NAOMI game, rendered at much faster speeds, while the new T&L GPU adds advanced lighting and particle effects. It was also more affordable than the very expensive (and difficult to program) Sega Hikaru arcade system that preceded it. The NAOMI 2 was nevertheless more powerful than home systems at the time. As with the NAOMI, the NAOMI 2 was also available in GD-ROM and Satellite Terminal variants. It was Sega's last proprietary arcade system board; subsequent Sega arcade boards have been based on console and PC hardware.

Components

Deisgnators

Component

IC110, IC15

NEC PowerVR2 GPU (315-6267)

IC105

Sega 315-6289

IC1

Hitachi SH-4 CPU

IC27

BIOS 27C160 EPROM

IC30

FPGA Altera FLEX EPF8452AQC160-3 (QFP160)

IC31

FPGA Configuration Memory Altera EPC1064PC8 (315-6188)

IC16 to IC23, IC111 to IC118

Hynix HY57V161610DTC-8 2 Bank 512k x 16-bit (16Mbit) SDRAM (TSOP-II 50)

IC106, IC107, IC108S, IC109S

Hynix HY57V653220B 4 Bank 512K x 32Bit SDRAM (TSOP-II 86)

IC9, IC10, IC11S, IC12S

Hitachi 5264165FTTA60 1M x 16-bit x 4-banks (64Mbit) SDRAM (TSOP-II 54)

IC?? (near IC1)

Altera EPM7032AELC44-10 CPLD Sega 315-6268 (PLCC44)

IC45

Sega 315-6146 (QFP176)

IC52

Analog Devices ADM485 +5 V Low Power EIA RS-485 Transceiver (SOIC8)

IC37

Sharp PC910 Ultra-high Speed Response OPIC Photocoupler (DIP8)

IC33

Yamaha AICA (Sega 315-6232) Super Intelligent Sound Processor

IC7

Altera MAX EPM7064AETC100-10 CPLD Sega 315-6269 (TQFP100)

IC5, IC41

Video Encoder Sega 315-6258 (QFP56)

Shared Components with Dreamcast

The NAOMI and NAOMI 2 share the following components that can be directly used from a Dreamcast if needed for repairs.

  • PowerVR2 GPU @ 100MHz (315-6226)
    • Dreamcast = IC201
    • NAOMI 2 = IC15 + IC110
  • Hitachi SH-4 CPU @ 200MHz
  • Yamaha AICA (315-6232) Super Intelligent Sound Processor
    • Dreamcast = IC301
    • NAOMI 2 = IC33
  • Video Encoder (315-6258)
    • Dreamcast = IC401
    • NAOMI 2 = IC5 + IC 41

Apprently the PowerVR2 from the Dreamcast is 720 MFLOP processing speed, while NAOMI is 1 GFLOP (30% faster). However I have successfully used a Dreamcast IC on a NAOMI 2 without issues.

Test Button

On the front panel there are two switches labelled PSW1 (Test) and PSW2 (Select).

PSW1 is the test button switch. Press this during boot to enter the diagnostics menu where you can test RAM, ROM and other things.