SG-1000

The SG-1000, which means Sega Game 1000, is Sega's first console, and while it was not really popular, it's later revisions became the successful Sega Master System.

History
The SG-1000 was test marketed in Japan in 1981 and first released to the Japanese market on July 15, 1983 for ¥15,000. The console reached minor success in that market and sold moderately well within Asia until 1985. The system was launched in New Zealand as released by Grandstand Leisure Limited, Australia and in other countries, such as Italy, Spain, and South Africa. The console in its original form was never launched in North America.

Game manufacturer Tsukada Original produced the Othello Multivision, an SG-1000 clone. Bit Corp's Dina 2-in-1 ColecoVision clone was brought to North America by a company called Telegames. Telegames called its clone the Telegames Personal Arcade, which could play ColecoVision and SG-1000 games.

A caveat is the SG-1000's surprisingly wide availability on Taiwan's secondary market. This console is highly significant in Taiwan as one of its first and best-remembered consoles, where it was manufactured and sold (very briskly) under license as "阿羅士" ['Lou Shi'].

Taiwan, among a few other countries, also received a "Mark IV" version of the console (most likely a modified Sega Master System II) and the Mark naming convention was further extended to the Mega Drive/Genesis ('Mark V').

SG-1000 Mark II
In July 1984, Sega released an updated version of the console called the SG-1000 Mark II. It is functionally identical to the Mark I, but has a re-styled shell and the connector for the optional plug-in SK-1100 keyboard has been moved from the rear to the front. It was initially priced at ¥15,000. A computer version of this console, with a built-in keyboard, was called the SC-3000, which would go on to outsell the SG-1000.

The SG-1000 runs all SC-3000 games and applications, with the exception of Music and Basic Cartridges. The machine could be used just like the SC-3000, provided one had the keyboard attachment ready. The console also had an optional game card reader add-on called the Card Catcher that allowed for the use of Sega game card software.

The Card Catcher would become built into the SG-1000 Mark III, as well as the first version of the Sega Master System.

SG-1000 Mark III
The SG-1000 Mark III, a yet newer version in Japan with improved video hardware and an increased amount of RAM, would be redesigned and released in the western world as the Sega Master System.

SG-1000 Clones
Due to the popularity of the console in several regions, some companies cloned this system for commercial use without the permit from Sega.

Othello Multivision
The Othello Multivision (オセロマルチビジョン) is an SG-1000 clone manufactured by Tsukuda Original. It exists because Sega's original intention for the SC-3000 computer was to allow other manufacturers to produce compatible computers in the hope of having a worldwide standard. Unfortunately, possibly with the emergance of the MSX, this tactic failed, and very few SG-1000/SC-3000 compatible machines were produced. The Othello Multivision was one of those machines.

Similar to the SG-1000, there are two versions of the Othello Multivision, named the FG-1000 (released 1983) and FG-2000 (released 1984) respectively. As well as being able to run SG-1000 and SC-3000 cartridges, the Othello Multivision saw a number of games and software released with Othello Multivision branding. The system also came with the game Othello built-in.

One of the major problems with the Othello Multivision is that rather than rely on external game controllers, all the controls are built into the unit. It is compatible with several SG-1000 add-ons, however, including the SK-1100 which would enable the SC-3000's keyboard functions. FG-1000 models shipped with an overlay which would explain the functions of each key.

The FG-2000 model brought support for a second controller. This model can easily be identified by the fact it uses blue keys rather than red ones and the fact the built-in joystick has been replaced with a directional pad.

Dina 2-in 1
The DINA 2 in One, originally known as the Chuang Zao Zhe 50, is a video game console manufactured by Bit Corporation, a Taiwanese electronics company. It is a hybrid console with the ability to play ColecoVision and SG-1000 games. This hybrid was possible due to the fact that the ColecoVision and SG-1000 have nearly identical hardware; the two systems share the same CPU, VDP and sound chip.

The design of the DINA seems to be heavily inspired by the SG-1000 II. It uses gamepads similar to the SG-1000 II, with a D-pad and unlabled  and  buttons. The controllers also slide into the sides of the unit to save space. A numeric keypad exists on the front of the console itself for use with ColecoVision games, as well as a pause button for SG-1000 games. As expected, the pause button does not work with ColecoVision games and the keypad is incompatible with the SG-1000.

The vast majority of both ColecoVision and SG-1000 games are compatible, however there are some exceptions. ColecoVision games which require the keypad for actual gameplay are more difficult to play, and ColecoVision controllers are incompatible with the system. This also means that games which require the ColecoVision's Super Action Controllers or Expansion Module #2 cannot be played. SG-1000 and Master System controllers are compatible, however.

At the rear of the system is an expansion port, which is not compatible with ColecoVision or SG-1000 add-ons, such as the ColecoVision's Expansion Module #1 (which allows for the play of Atari 2600 games) or the SK-1100 keyboard. The system also lacks a switch for when both a ColecoVision and SG-1000 game are inserted. A small leaf switch was placed inside the SG-1000 slot in order for the system to differentiate which slot is being used.

The cheap price also leads to a cheaply made console. The VDP in particular is prone to overheating due to the lack of a heat sink, a required component for TMS9918-series VDPs. It is also a much lighter and smaller unit than either the ColecoVision or SG-1000 and is constructed out of low-quality plastic. The RF output (which is NTSC) is also very prone to interference and is tuned to channel 13 (channels 2-4 are used for RF output in North America); this can be remedied through an AV mod. The controllers are also of poor quality and have short, stiff cords.

Specifications

 * CPU: NEC 780C (clone of Zilog Z80)
 * 3.579545 MHz for NTSC, 3.546893 MHz for PAL
 * Main RAM: 8 kbit (1 kB)
 * Video RAM: 128 kbit (16 kB)
 * Video processor: Texas Instruments TMS9928A
 * 256x192 resolution
 * 32 sprites
 * 16 colors


 * Sound: Texas Instruments SN76489
 * 4-channel mono sound
 * 3 sound generators, 4 octaves each, 1 white noise generator
 * Ports:
 * 1 Parallel
 * 1 Cartridge
 * 1 Cassette
 * 1 Composite video
 * 2 Joystick
 * 1 Keyboard (Mark II only)