The MOS Applied sciences 6581, or SID, is maybe the built-in circuit whose sound is most sought-after within the chiptune world. Its three voices and mixture of waveforms outline a lot of our collective reminiscences of Eighties computing tradition, so it’s no shock that fashionable musicians hunt down SID synthesisers of their very own. One among these is the MIDISID, produced by [MIDI IN], and in a latest video she investigates an sudden tuning downside.
It began when she obtained buyer experiences of SIDs that had been out of tune, and within the video she delves deeply into the topic. The unique SID gained its timing from a clock sign supplied by the Commodore 64, with thus completely different timing between NTSC and PAL variations of the machine. This meant European SID music wanted completely different software program values to American compositions, and alongside the way in which she reveals a localisation error in that the British Commodore 64 guide had the fallacious desk of values.
Trendy SIDs are emulated until you occur to have an authentic, and her downside got here when switching from one emulated SID to a different. The primary one used that clock pin whereas the second has its personal clock, leading to some music being off-tune. It’s an easy firmware repair for her, however an attention-grabbing dive into how these chips labored for the remainder of us.
Picture: Taras Younger, CC BY-SA 4.0.
