Q2 Front Panel
The front panel occupies the lower left side of the Q2 PCB. There are 12 address LEDs, 12 data LEDs, and 12 switches to allow one to view and input addresses and data:
The address LEDs simply show the state of the address bus:
Likewise, the data LEDs show the state of data bus:
The switches allow loading data on to the data bus when the "deposit" button is pressed or load the program counter on reset.
Although a classic interface for an old minicomputer, the front panel interface is not very practical for loading programs. Thus, the pins are exposed through a 40-pin header to allow a Raspberry Pi to be used as a programmer:
