The Electric Christmas Tree
This was the first electronic Christmas display I made. I used 3/8 inch plywood on a 14 foot tall pyramid-like frame of 2 by 4 lumber. Since I was on a acreage, this was easy to put up and store every winter, but after dragging it around to a couple other locations in the Province and struggling to find a place for it, I retired it in 1994.
I driied about 300 holes in the plywood and installed 10 watt bulbs in the shape of a Spruce Tree in the holes. The back of the display had all the wiring, and there was LOTS of it! Forty-eight separate digital signals from 3 circuit boards lit the lights in various patterns and various colors. All wiring was #16 gauge and the cables that connected the "tree" to the electronics were 14 conductor #16 cables, terminated at both end with high grade military-style connectors.
I built the 6809-based computer, interface board with PIAs and the 3 triac boards. I wrote the program in assembly language.