This does not use pseudo-random math like all software random number generators.
It is turned on by a microswitch connected to one of the broader sides, which is hinged.
Two oscillators at 2.97 and 3.06 MHz are divided by 12 using SN7492s. These are divide by 6 using shift registers and a separate divide by 2, which is not used. After about 40 ms the clocks are stopped and the three outputs of both divide-by six are used to show two throws on the red LED matrix like the spots on 2 dice.
This stays on until the microswitch is released.
It is very old.
This device still works, is displayed prominently and can be instantly used.