18 votes
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What could SID do that APU could not?

I don’t know that this adds much beyond the information already in the question, but… A perennial problem with the SID is playing music at the same time as generating sound effects, due to the fact ...
Tommy's user avatar
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16 votes
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How did I fry my SID chip?

The amplifier input is biased to about half supply voltage. The SID output is also biased to about half supply voltage. You have little or no bulk/bypass capacitance on the 9V supply pins, so abruptly ...
Justme's user avatar
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14 votes

Was the output of the C64 SID chip 8 bit sound?

The output is analog, not 8-bit. Each channel has an 8-bit DAC inside to generate the selectable waveforms (sine was not one of them, square/pulse wave, triangle and saw). There were also volume and ...
Justme's user avatar
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12 votes
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Commodore 64 sound seems to freeze at a high pitch if executed too soon after startup

As only a fragment of your code is available for review, it's hard to assess as the devil is generally in the detail. However, from your VOICE_1_FREQ_HI ;$D401 reference, I note that you seem to be ...
Retrograde's user avatar
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10 votes

What could SID do that APU could not?

The NES had two voices that were designed to produced pulse-wave tones with adjustable volume, one fixed-volume triangle wave output, an adjustable-volume noise channel, and a digital audio output ...
supercat's user avatar
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10 votes
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Are the 16 linear steps of the SID Sustain and Filter Volume/Resonance steps of 6.25 or 6.666666667?

0 represents 0% and 15 represents 100%, so 100%/15 ≈ 6.67% per step is correct. You've got 16 values (0..15), encompassing only 15 intervals.
Zac67's user avatar
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10 votes
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Are SID Players practically almost full-fledged C64 Emulators?

SID files are music programs. They normally contain two 6502 ML routines- one for initializing the hardware, and another to serve as a periodic interrupt handler that will update the SID registers as ...
Brian H's user avatar
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9 votes

Was the output of the C64 SID chip 8 bit sound?

Part 1: Was the output of the C64 SID chip 8 bit sound? Short Answer: yes The term 8-bit sound is generally not related to any sample size or speed, but to describe the sound 'qualities' of the 8-...
Raffzahn's user avatar
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4 votes
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What was the die size of the 6581 SID?

Looking at a series of stepped die shots, and knowing that the steps were 0.5mm one way and 0.45mm the other way, we can estimate the die area as about 27.2 mm².
Chromatix's user avatar
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4 votes

SID to WAV converter that exports per channel separately

I'm not sure about built-in support for rendering per-track wave files automatically, but you could write a batch file or shell script to drive a command-line SID-to-Wave tool to play it multiple ...
ssokolow's user avatar
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4 votes

Was the output of the C64 SID chip 8 bit sound?

Or maybe what I am really asking is: If I have an 8 bit, 44 kHz sample based audio chip, could that chip generate audio which could not be distinguished from a real SID chip? The short answer: ...
cjs's user avatar
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3 votes
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SID, sampled sound and bad lines

One might select sampling rate to be half the display lines rate (around 7.8 kHz) and arrange things so, that CPU always gets interrupted to play digital at odd lines, not interfering with bad lines.
lvd's user avatar
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2 votes

Are there Commodore BASIC 7.0 music demos?

While not exactly examples of outstanding music, I knew that there was a C128 demo program written in BASIC to show off the capabilities of BASIC 7.0. In addition to graphics, it also demonstrated ...
bjb's user avatar
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2 votes

Was the output of the C64 SID chip 8 bit sound?

The waveform generator and DAC of each of the three voices is 12-bit, and calculates a new value for the DAC at the system clock speed, approximately 1 MHz. The subsequent envelope generator and ...
Chromatix's user avatar
  • 16.8k
2 votes

How did I fry my SID chip?

This sounds like an ESD/over voltage event might have occurred while you were working with the circuit. The SIDs are extremely sensitive. It is not uncommon for a defective SID to draw excessive ...
Retrograde's user avatar
  • 4,506
1 vote

Are there Commodore BASIC 7.0 music demos?

For the records: I just found some C128 BASIC music program using PLAY commands in the Dual Demo by Flexman The music code is at line 7000 and following.
Peter B.'s user avatar
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