Elliott 803B computer playing Popcorn

Short clip of an Elliott 803B computer from the 1960s driving the monitor speaker to play 'Popcorn'.

The scope (resting on one of the 803B's system cabinets) is displaying the accumulator and the instruction register. The tune comes from a speaker inside the illuminated console against the wall.

Taken at the National Museum of Computing, during the Vintage Computer Festival of Great Britain (VCF-GB) 2010 at Bletchley Park, near Milton Keynes.

Edit: Not really 'bit-banging', the speaker output comes directly from a control line in the CPU, rather than an output register toggled by the program. Every Elliott 803 program makes its own characteristic noise, more often than not a mid-range burbling sound. Here shift instructions, whose execution time is proportional to the shift distance, are used to make a variable delay and produce periodic clicks on the speaker, heard as a tone.

Category:

Science & Technology

Tags:

• Singing computer
• computer music
• bit banging
• chiptune
• big iron
• retrocomputing
• Elliott 803
• Gershon Kingsley
• Hot Butter
• Popcorn
• VCF GB 2010
• TNMOC

[PeterOGB]

It is not "bit banging" the speaker. The speaker is connected to the top bit of the instruction register so the sounds are a side effect of the particular instruction sequence. Of course for playing music the instruction sequence is determined by the note required.

[regregex]

@PeterOGB Well okay, it's not toggling an output by writing to it. However it's doing the rest of what's understood by bit-banging -- i.e. state-change, wait, state-change, wait, directly by the CPU instead of an autonomous timer.

[PeterOGB]

@regregex It's the fundamental operation of the CPU that makes the sound. Every program makes sound, you can't stop it making a sound(except by turning down the volume). It doesn't "wait" either, the instructions are chosen to take the right length of time (e.g. multi-place shifts which take a time proportional to the number of places shifted).