Modern SID chip substitutes [video]
67 points
4 days ago
| 5 comments
| youtube.com
| HN
mycall
10 hours ago
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What makes the SID chip special are the analog filters. Otherwise, it is easy to emulate as the video shows. MIDISID 4 and Elektron SidStation can access the filters for a wide range of sounds.
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layer8
13 hours ago
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SID piece from the beginning of the video: https://www.youtube.com/watch?v=YIA_0cvS2gQ
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CalRobert
15 hours ago
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Long shot but who knows…

There was an awesome c64 music radio show on KDVS (the UC Davis radio station) back in the nineties, but I can find zero record of it existing. Does anyone on this thread know anything about it, or even perhaps have recordings?

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phendrenad2
16 hours ago
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I wonder how hard it would be to make a SID using transistors, capacitors, resistors. The fact that no one has done it makes me think it's just too difficult.
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NobodyNada
9 hours ago
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Similar idea: https://monster6502.com/

But note:

> Does it run at the full speed of an original 6502 chip?

> No; it's relatively slow. The MOnSter 6502 runs at about 1/20th the speed of the original, thanks to the much larger capacitance of the design. The maximum reliable clock rate is around 50 kHz. The primary limit to the clock speed is the gate capacitance of the MOSFETs that we are using, which is much larger than the capacitance of the MOSFETs on an original 6502 die.

So if you built a SID using the same techniques and components, you couldn't run it in real-time without the pitch being way too low or without modifying the design. I'm not sure how hard this would be to avoid with better-spec'd components, but intuitively it makes sense for a much larger circuit to run much slower.

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Neywiny
16 hours ago
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A light googlin says estimates are that the SID is maybe 2k transistors. I think a reasonable minimum is in the thousands.
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snvzz
9 hours ago
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logic could be in a CPLD or FPGA, leaving only the analog portion discrete.
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unwind
2 hours ago
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At the speeds in question, I'm pretty sure the logic could be in a general-purpose microcontroller, too. But I'm not sure detailed schematics for the analog parts are available/open.
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LouDNL
22 hours ago
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Each one would fit perfectly on USBSID-Pico
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MomsAVoxell
18 hours ago
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Imagine a stack of 4 of them, nicely multi-timbral...
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