The SC-3000 is a computer based on the hardware of the first videogame systems released by Sega in Japan : the SG-1000 series. It can use the same game cartridges marketed for these consoles.
The SC3000 can't be used without a ROM cartridge, which can be either a game or language. There were three different BASIC cartridges. One came with only 1Kb of RAM (and you had only 512 bytes free !), the second with 16Kb and the last with 32Kb. In official adverts, they show a total RAM of 48Kb. This was counting the VRAM and the 32Kb BASIC cartridge...
Several great games were adapted by Sega for this computer. Several graphic characteristics of the SC-3000 are fairly close to MSX ones. For example, it was one of the first computers to offer 32 sprites.
Some months later, Sega released the SC-3000 H which was the same system but with a mechanical keyboard.
This computer was also marketed by Yeno under the same name (Yeno SC 3000 & SC 3000H). It was exactly the same computer except for the Yeno brand.