The system with the two controllers.
It looks like an old tape player,
and is same as the National Adversary from NS.
The Heathkit GD-1999 is a strange system. Although Heathkit was famous for selling high
quality products, the GD-1999 was not a real kit. In fact, it was a clone of the
National Semiconductor Adversary system (model 370), released shortly after NS launched
the MM-57100 game chip in 1976. Only the labels of the unit and controllers
differ between the two brands.
The reason why this system is not a real kit is the assembled circuit board.
Usually, the fun of assembling kits was to solder the various components on
the circuti board, verify that no error was made, make the necessary wirings
to the power supply, inputs and outputs, and then go through tests and
adjustments. Here, nothing of that was required, as the circuit board came
already assembled, adjusted and tested. Only a few solders were required
to wire the controllers to the circuit board, after what it would be put into
the case, which would then be screwed. This was so simple that the user
manual took four double-sided A4 pages (unlike the thick 100-page manual full of
illustrations and details of the GD-1380 game, which was a
Talking about the electronic circuit board provided by National Semiconductor, another
obscure system (supposedly a kit) was made by GEMINI (model 7640) and used the same circuit.
If the Gemini 7640 was released in late 1976, the GD-1999 was released in 1977 and sold at
a very low price. Not many were sold (maybe a few thousands or less: the pictured
system is one of the first 800 produced).