The SG-1000 was released simultaneously with a home computer version with almost identical hardware, the SC-3000. It seems to have been cloned from the ColecoVision hardware.
There are 3 models, quite similar in specs:
CPU: Zilog Z80 @ 3.58 MHz
GPU: Texas Instruments TMS9918
Audio: Texas Instruments SN76489
Specs:
Memory : 1 KB RAM Resolution : 256x192 Colors : 15-color fixed palette Tiles : 8x8 pixel tiles Sprites : 32 single-color sprites, max 4 per horizontal line Audio : 3 square waves, 1 noise
ocdgamer.rb:336:output_game_list( 19 games, mode:largebox, tag id:88, sortby:year, url_arg_prefix:, output_list_selection:true) output_large_game_box(3727) output_large_game_box(3728) output_large_game_box(3733) ... execution time: output_game_list: 0.00s