Gakken is a Japanese magazine that comes with a DIY kit. Prior issues featured a theremin and of course the analog SX-150 mini synth [see the Gakken label below for prior posts including images, videos and mods]. The current issue comes with the GMC-4, a 4-bit computer kit with audio. See the video below.
via Hobby Media
"Gakken is going to release the very first 4bit computer mass produced in the last 30 years: the GMC4. This microcomputer will be covermounted on the issue 24 of the magazine “Otona no Kagaku”. The GMC4 got a 16 keys keyboard, an inbuild speaker an outsanding 7 elements LED display and a 6 LEDs display.
Tennis game, melody software and two other 4bit videogames are preinstalled in the GMC4. This 4bit computer will be released in June and in the coming weeks Gakken shuld updated their website with some mode details about this great retrocomputer."
You can find issues of Gakken with kits on Ebay here.
YouTube via OKM080725