Sega SC-3000
This page was last modified 22:25, 5 January 2022 by Mars2000you. Based on work by Bodhi1969 and Gdx and others.
SC-3000 logo



The SC-3000 has a hardware close to MSX standard. The main difference is the sound chip.

The SC-3000 (Sega Computer 3000) is the first computer to be designed and manufactured by Sega. It was first released in July of 1983 in Japan, and serves as the home computer equivalent of the SG-1000 cartridge-based video game console. The SC-3000, often known simply as the "Sega Computer" or even just the "Sega", is an 8-bit home computer almost identical in nature to the SG-1000 with its optional keyboard (SK-1100).

Unlike later Sega systems, the SC-3000 did not receive a worldwide release, but in markets where it did compete, including Japan, Australia, New Zealand, France, Italy and Finland, the computer fared well as a low price, entry-level machine for the home. By 1985, the SC-3000 had been displaced by more popular computer standards, but is nevertheless said to have fared better than the SG-1000 console on the global stage, and has a strong group of followers to this day.

The company would partner with Amstrad and IBM for the Amstrad Mega PC and TeraDrive respectively in later years, but other endeavours such as the extremely rare Sega AI Computer saw only a small fraction of the success the SC-3000 received, and were built with very different aims.

By default, the SC-3000 has 2kB of work RAM and 16kB of VRAM. The system's main RAM is dictated by the cartridge inserted into the machine, and the system will not function if the cartridge port is empty. RAM only becomes an issue when dealing with software not distributed on cartridge, and so, even though the systems are similar, differing RAM requirements from software is not an issue that can affect the SG-1000.

The SC-3000 is available in three colors (black, off white, red). Price at launch ¥29,800 (without BASIC).

Sega also released the SC-3000H which is the same but with a better keyboard.

Brand Sega
Model SC-3000
Year 1983 (Japan)
Launch price ¥29,800
Media Cartridges
Video Texas Instruments TMS9918A
Audio Texas Instruments SN76489A
Keyboard layout {{{keylayout}}}
Emulation meka


Sega SC-3000 white
Sega SC-3000 red
Sega SC-3000 black
Sega SC-3000 black bottom
Sega SC-3000 black rightside
Sega SC-3000 black leftside
Sega SC-3000 black packging
Sega SC-3000 black & Basic set
French Sega SC-3000 black packging
Sega SC-3000 black PAL
Sega SC-3000 black PAL box
Sega SC-3000 black PAL box topside


CPU is a NEC Z80 (μPD780C-1) or a Sharp (LH0080A) with 2kB RAM (C000h~C8FFh). The SC-3000 has no ROM just like the SG-1000.

The SC-3000 RAM is expandable with following cartridges and/or the SF-7000 Super Control Station:

  • BASIC Level II A: It contains 515 bytes RAM + 32kB ROM (BASIC interpreter)
  • BASIC Level II B: It contains 1kB RAM + 32kB ROM (BASIC interpreter)
  • BASIC Level III A: It contains 16kB RAM + 32kB ROM (BASIC interpreter)
  • BASIC Level III B: It contains 32kB RAM + 32kB ROM (BASIC interpreter)
  • SF-7000 Super Control Station: It contains 64kB RAM + a 8kB ROM (Initial Program Loader) + 3" Floppy Disk Drive + RS-232C Serial Port + Centronics Parallel Port. A Sega system disk is required to use BASIC, the system disk must also be used before a disk with games or applications.

Controller ports use same connector as MSXs but pins 7-9 have different order. Pinout is same as SG-1000 (up to Master System). Do not insert Sega controllers into an MSX without JoyMega.

Run SG-1000 software on MSX

SC-3000 software can't run on MSX without some changes. None were converted

The differences between the SC-3000 and MSXs are:

  • Memory map
  • Used I/O ports
  • PSG is a SN76489 instead of AY-3-8910 (noise generator is on a separate voice)
  • Controllers
  • Keyboard access


  • RF-output
  • Analog sound and composite video output (5-pin DIN 41524)
  • RGB output (Yeno model only)
  • Data recorder connectors (Female Jack plug 2.5mm x 2)
  • Printer port (7-pin DIN 45329)
  • SG-1000 cartridge slot
  • 2 joysticks ports for the joystick 2 (DE-9 type), joystick 1 can't be removed
  • Power supply input (+9V, 850mA, minus at the center)


Fixes and upgrades