development 1975-1978, produced a total of approx. 200 units
In 2024, former VUMS developer Václav Daněček shared about the interesting implementation of the front panel: "Unlike HP, which had such a cradle, we had a double button Up/Down and a clear button, because it was so easy to enter without you'd have to look at what's there. The button was a flip-flop made of two 7400 gates and could be reset and reversed with a button, so it was an I/O device. In my opinion, it's the pinnacle of perfection in TTL and it shouldn't be forget it :D"