Commodore 64 Christmas 1982 Demo

Somewhere around early December in 1982, a Commodore 64 Christmas demo was splashed across monitors in nearly every department store in that era.

The selling point to this demo, is that the purchase of a new SX-64 came packaged with this test/demo diskette that showcased the computer’s amazing multicolor graphics and sound capabilities. Even though it wasn’t actually included with a brand new Commodore 64 system, the demo still encouraged the sales of the other machine.

The Commodore SX-64 (also known as the “Executive 64”) was a portable computer that came included with a mini 5 inch monitor. It was the first full color portable computer

The Commodore 64 utilized a special type of graphics made called Multicolor that allowed the computer to utilize up to 4 pixel colors in an individual 8 x 8 block. Although it only managed 4 colors, by setting these characters up side by side, the system could generate some fantastic displays, even for just an 8-bit machine as demonstrated in the Commodore 64 Christmas Demo.

The SID system contained 3 voices total that was made up of various instruments. The Commodore 64 utilizes pulse waveforms, control registers, envelope (ADSR) control, attack/decay, sustain/release, filter cutoff frequency, filter resonance control, and volume for the voices. These are listed below with the appropriate memory register:

Memory Register



Voice 1 Frequency


Voice 2 Frequency


Voice 3 Frequency


Voice 1 Pulse Waveform


Voice 2 Pulse Waveform


Voice 3 Pulse Waveform


Voice 1 Control Register


Voice 2 Control Register


Voice 3 Control Register


Voice 1 Attack/Decay


Voice 2 Attack/Decay


Voice 3 Attack/Decay


Voice 1 Sustain/Release


Voice 2 Sustain/Release


Voice 3 Sustain/Release


Filter Cutoff Frequency


Filter Resonance Control



Robert Russell has been famed with being involved with the Christmas demo. He was involved with the trade fairs back in the early days of promoting the Commodore computers, which included attending the Comdex trade fair in 1980. This was during the time of the VIC 20’s introduction and growing interest.

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