These Compo 80/BS systems (BS stands for Basic) are in fact based upon the NEC TK-80 board system. There are a kind of "all-in-one" offer with a TK-80 board, a plastic case, a real keyboard, a tape-recorder or a numeric keypad and several other boards...
The Compo BS/80A has a remote controled tape-recorder built-in (1200 bauds) whereas the BS/80B must use an external tape-recorder (300 bauds).
A weird feature is that you have to use a key to unlock the system. The keylock is placed above the keyboard on the left-hand side (black square on the picture).
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