My long-awaited delivery of hardware arrived yesterday, including a protoboard, tools, and about half the components I need to build the machine. I’m using the protoboard to try various test circuits, before I construct the real thing on the wire wrap board. Last night I geeked out with the protoboard, and threw together some sample circuits.

I cut the tip off an old 9V laptop power supply, and wired it to the Vcc and ground terminals of the protoboard. Then I used a 5V voltage regulator and some capacitors (at right in the photo) to get a smooth 5V supply for the other components. The silver rectangle is a 1MHz clock oscillator. The yellow chips are resistors used to limit the current through the LED, and pull up the voltage at the push-switch. The black chip is a 4-bit counter. I wired the push-switch to the counter’s clock input, and the LED to the lowest bit of its output. Every time I press and release the switch, it clocks the counter, the low bit switches between 0 and 1, and the LED toggles off and on. It’s digital baby!