From Sega Retro

SG-1000 logo.svg
Fast facts on SG-1000
Manufacturer: Sega
Variants: SG-1000 II, Othello Multivision, SC-3000, Pioneer TV Video Game Pack SD-G5, SG-1000-based arcade hardware
Release Date RRP Code
¥15,000[1] SG-1000[2]
? ?
NT$? ?

The SG-1000 (Sega Game 1000), known in New Zealand as the Sega 1000, is a cartridge-based video game console released in 1983 by Sega. It stands as Sega's first entry into the video game console market, and though was not seen as a huge success, gave the company more experience when dealing with future systems. It is now a rare and often sought after console.

The SG-1000 sold about 2 million units worldwide.[3] Its computer counterpart, released during the same period, is the SC-3000. There is also SG-1000-based arcade hardware. It had an improved version, the SG-1000 II, and was succeeded by the Sega Mark III, which was released worldwide as the Sega Master System.


The SG-1000 is a top-loading cartridge based video game console with a white and grey plastic finish. Compared to many other systems from around this era the SG-1000 sports a relatively simplistic design - a power switch, RF output and expansion port on the back, and a red pause button at the front.

The first controller (a SJ-200) is hard-wired into the unit and cannot be easily removed; however, a second controller can be connected through a DE-9 port on the right-hand side of the unit. Sega later released an adapter cable (known as the JC-100) that allowed for the use of standard detachable controllers and replaced the hard-wired joystick.

Internally the SG-1000 is roughly on par with the ColecoVision and original MSX standard, though has differing amounts of RAM. The similarities explain why the Telegames Personal Arcade is compatible with both the ColecoVision and SG-1000, and how in recent years a number of SG-1000 games have been unofficially ported to the ColecoVision (such as Doki Doki Penguin Land and Girl's Garden). In Taiwan and South Korea, several MSX games have also been ported to the SG-1000.

The SG-1000 is a much flatter console than people expect - its odd shape and aesthetics give the impression that it is a taller system than it actually is.

Controls were an issue for the SG-1000 - the SJ-200 is often criticised for being stiff and unresponsive, and should it break, there is no easy way to replace it. All future consoles by Sega would allow both controllers to be removed.

The SK-1100 keyboard is designed to be plugged into the back of the SG-1000, bringing the unit closer to the offerings of the SC-3000.


Main article: SG-1000 consoles.

Black stripe model

Early models in Japan had black labels and a slightly different logo (sometimes referred to as the "German Model" due to similarities with the German flag), but these are a considerably rarer sighting.

Blue stripe model

Unlike the early "German Model", the second, and most commonly found, model features a blue label rather than black.

Sega 1000

The model released in New Zealand, was renamed to "Sega 1000" and resembles the second Japanese model, with a blue stripe and the addition of Grandstand's name.

Technical specifications



  • Graphics chip: Texas Instruments TMS9918A[4]
    • Clock rate: 10.738635 MHz[4]
    • Pixel clock rate: 5.3693175 MHz (NTSC), 5.3203424 MHz (PAL)
    • Bus width: 8-bit
    • Color subcarrier frequency: 3.579545 MHz (NTSC),Media:SC-3000ServiceManual.pdf[6] 3.546893 MHz (PAL)
  • Screen resolution: 256×192 pixels[7]
  • Refresh rate: 59.922743 Hz (NTSC), 49.701459 Hz (PAL)
    • Frame rate: 59.922743 frames/sec (NTSC), 49.701459 frames/sec (PAL)
  • Color palette: 16 colors (15 colors + transparent)[8][7]
  • Sprites: 32 sprites on screen, 4 sprites per scanline, 2 colors per sprite, 8-16 bytes per sprite[7]
    • Sprites pixel sizes: 8×8 or 8×16 pixels (32 sprite pixels per scanline)
    • Integer sprite zooming: Up to 16×32 pixels
  • Background: Tilemap playfield, 8×8 tiles, 2 colors per tile, 8 bytes per tile[7]
  • VRAM: Fujitsu MB8118-12 DRAM,Media:MB8118 datasheet.pdf[9] 16 KB, 800-832 tiles[7]
    • Sprite attribute table: 128 bytes (4 bytes per sprite)
    • Sprite tiles: 256-512 bytes (32-64 tiles, 8 bytes per tile)
    • Background tiles: 6 KB (768 tiles, 32×24 tiles, 256×192 pixels, 8 bytes per tile)
  • VRAM pixel bandwidth:Media:SC-3000ServiceManual.pdf[10]
    • Read bandwidth: Byte per 8 CPU cycles, 447.443 KB/s (NTSC), 443.361 KB/s (PAL)
    • Write bandwidth: Byte per 16 CPU cycles, 223.721 KB/s (NTSC), 221.68 KB/s (PAL)
  • VRAM pixel fillrate: 1-bit per pixel
    • Read fillrate: 3.579545 MPixels/s (NTSC), 3.546893 MPixels/s (PAL)
    • Write fillrate: 1.789772 MPixels/s (NTSC), 1.773446 MPixels/s (PAL)
  • VRAM tile fillrate: 8 bytes per tile
    • Read fillrate: 39,761 to 49,855 tiles/sec (800-832 tiles per frame)
    • Write fillrate: 27,965 tiles/sec (NTSC), 27,710 tiles/sec (PAL)




The SG-1000 was first released to the Japanese market in July 1983 for ¥15,000. It was a minor success for Sega, but was held back from the start due to sharing the same release date as the Nintendo Famicom. It is rumoured to have been test marketed as early as 1981, being kept in stasis while kinks were ironed out in certain SC-3000 utility software.

Despite having some initial support from the likes of Konami, the console was largely abandoned by 1985, though staggered on to the late date of 1987 with The Black Onyx as the last official Japanese release.

In Japan the SG-1000 initially saw competition in the form of the likes of Epoch, Tomy, Takara, Bandai, Casio and Nichibutsu, all of which were wiped off the market by the Famicom's success. The SG-1000 fared much better than all of these systems, mostly due to a library of Sega-exclusive arcade games brought to the system though was never able to maintain a dominant position in the market. Furthermore, its computer counterpart, the SC-3000, contained all the features of the SG-1000 and more, and therefore made a considerable dent in SG-1000 sales.

The only known release outside of Japan for the original SG-1000 model was New Zealand where it was distributed and badged by Grandstand. Neither the console or any of its official variants ever reached North America, however the SG-1000 compatible Dina 2 in one was released in the US by Telegames. The SC-3000 was released in Australia (John Sands), New Zealand (Grandstand), France (ITMC), Italy (Melchioni), and Finland (Digital Systems). As a result, the SG-1000 likely stands as Sega's worst performing video game console on record in terms of units sold, but Sega likely still profited from the venture.

In July 1984, Sega released an updated version of the console called the SG-1000 II, which moved the rear expansion port to the front of the system (used for the SK-1100 keyboard) and updated the controllers with an appearance similar to that of the Famicom. Outside of Japan the SG-1000 II is only known to have made it to Taiwan where it was distributed and badged by Aaronix.

Sega were very experimental during the early days, licensing game manufacturer Tsukuda Original with the rights to produce the Othello Multivision, an SG-1000 clone. An early plan of action seems to have been to create a computer game standard, allowing companies to focus more on games than on hardware - something which later be realised in Japan with the MSX, at the expense of the SG-1000.

Bit Corp produced the Dina 2 in one SG-1000 clone, likely without a license, which also had the ability to run ColecoVision games. In North America this was distributed by Telegames as the Telegames Personal Arcade. The SG-1000 was also released in "module" form as the Pioneer TV Video Game Pack SD-G5.

Ultimately all SG-1000/SC-3000 variations failed to capture the market share Sega had been aiming for, leading to the creation of the Sega Mark III, another revision of the hardware in Japan with improved video hardware and an increased amount of RAM. This would later be the basis of the Sega Master System, and both the Japanese Mark III and Master System are backwards compatible with the SG-1000. Many unlicensed Master System games run in the mode intended for SG-1000 compatibility, and are therefore, in a sense, SG-1000 games.


List of games

Main article: List of SG-1000 games.


Othello Multivision

Cancelled titles

Promotional material



  3. Co-opetition (Page 238)
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 MAME's SG-1000 driver
  5. Obsolete Microprocessors
  6. File:SC-3000ServiceManual.pdf, page 16
  7. 7.0 7.1 7.2 7.3 7.4 Sega Game 1000 (SG-1000) Information (Draft)
  8. TMS9918
  9. 9.0 9.1 9.2 File:MB8118 datasheet.pdf
  10. File:SC-3000ServiceManual.pdf, page 14
  11. 11.0 11.1 11.2 SN76489
  12. SG-1000 (Sega)
  13. File:SC-3000ServiceManual.pdf, page 15
  14. Service Games: The Rise and Fall of SEGA: Enhanced Edition, page 17
  15. 15.0 15.1 File:SC-3000ServiceManual.pdf
Sega SG-1000 Hardware
 SG-1000 Variations   SG-1000 | SG-1000 II | SC-3000 | SC-5000 | Othello Multivision | SD-G5 | Arcade
Add-ons   Super Control Station SF-7000 | 4 Color Plotter Printer | Data Recorder SR-1000 | Sega Keyboard
Game Controllers   Joystick (SJ-200) | Joystick (SJ-300) | Joypad (SJ-150) | SJ-151 | Handle Controller | Bike Handle | Sega Graphic Board
Misc. Hardware   Card Catcher | JC-100 | SD-80 |Sega Compact Floppy Disk
Unlicensed Clones   Dina 2 in one | Fullwis Video Game FR-II‎
Sega Home Video Game Systems
83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11
SG-1000 SG-1000 II Mega Drive Mega Drive II
SC-3000 Mega-CD Mega-CD II Genesis 3
Sega Mark III Saturn
Master System Master System II
Game Gear
32X Dreamcast
Pico Beena