 It was a very small machine built on two cards, one with an LED display, keypad, and cassette interface (the circuitry to the left of the keypad), and the other with the rest of the computer (including the CPU).Almost all CPU signals were accessible via a Eurocard connector.The System 2 made it easier to expand the system by putting the CPU card from the System 1 in a Eurocard rack that allowed a number of optional additions.