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The Atari 2600 Music and Sound Page

Table of Contents

This page contains adapted information and charts related to Atari 2600 music and sound. All information on this page was used with permission.

 

 

 

 

 

Atari 2600 VCS Distortion Descriptions

The following chart is adapted from Atari 2600 VCS Precise Sound Values and Distortion Breakdown by Glenn Saunders:

 
 

Tone

What it Sounds Like

     
     
 0

No sound (silent).

     
     
 1

Buzzy tones.

     
     
 2

Carries distortion 1 downward into a rumble.

     
     
 3

Flangy wavering tones, like a UFO.

     
     
 4

Pure tone.

     
     
 5

Same as 4.

     
     
 6

Between pure tone and buzzy tone (Adventure death uses this).

     
     
 7

Reedy tones, much brighter, down to Enduro car rumble.

     
     
 8

White noise/explosions/lightning, jet/spacecraft engine.

     
     
 9

Same as 7.

     
     
10

Same as 6.

     
     
11

Same as 0.

     
     
12

Pure tone, goes much lower in pitch than 4 & 5.

     
     
13

Same as 12.

     
     
14

Electronic tones, mostly lows, extends to rumble.

     
     
15

Electronic tones, mostly lows, extends to rumble.

     
     

 

 

Summary:

 

Unique

Redundant 

0
11
1 2 3 4
5
6
10
7
9
8 12
13
14 15

 

 

 

 

 

 
 

Atari 2600 VCS Sound Frequency And Waveform Guide
(c) copyright by Eckhard Stolberg (Eckhard_Stolberg@web.de)
Based on the version that was last modified on May 25, 2000 (version 1.01)
Adapted by Duane Alan Hahn (with permission)

F & W Guide Contents

Related Links

Tone Toy 2008

Makes it easy to play with Atari 2600 sound effects. Useful for hunting down what you need for sound effects and music. You can then shape what you've found until it sounds just right with the VbB Music and Sound Editor.

 

Real Atari 2600 Sounds Online

Move your mouse pointer and hear real Atari 2600 sounds.

 

VbB Music and Sound Editor

Create music and sound effects the fun way. The editor has many cool features and it uses real Atari 2600 sounds.

Atari 2600 BASIC

If assembly language is too hard for you, try batari Basic. It's a BASIC-like language for creating Atari 2600 games. It's the faster, easier way to make Atari 2600 games.

Try batari Basic

These tables have been calculated with the information found in Ron Fries' TIASOUND emulation package. Eckhard Stolberg did some sampling on his own to verify it and got basically what Ron's theory suggested. Also he has compared his results with Glenn Saunders' note tables and found them to be almost the same.

 

However, Eckhard Stolberg might have missed something important or simply miscalculated some of the values. Therefore it would be nice, if someone could do some sampling or recalculating to verify or correct these tables.

 

The cent values have been calculated with rounded frequencies. Therefore they are not as accurate as they might look, especially the ones for the lower frequencies.

 

 

 

 

 

How the Atari 2600 VCS Produces Sound

The Atari 2600 VCS produces its sound with some shift registers of various lengths. The speed at which it shifts the registers can be set to either the pixelclock/114 or to the CPUclock/114, which means two shifts per scanline or a third of this. Since a NTSC VCS produces 262 scanlines per frame and 60 frames per second this results in output rates of 31440 Hz and 10480 Hz. PAL TVs produce only 312 scanlines and 50 frames, so the output rates are only 31200 Hz and 10400 Hz.

 

A pitch value of n stored in the AUDFx registers modifies the frequency in a way, that n possibilities to shift are left out.

 

The distortion values stored in the AUDCx registers select the clock to use. They also select two shift registers of various lengths. One of these is the source pattern. Every time a 1 is shifted out of the source pattern, the output is set high. If a 0 is shifted out, the output is set low.

 

The other shift register is a clock modifier. Every time a 1 is shifted out, the effect of the source pattern can take place. If a 0 is shifted out, the bit, that is shifted out of the source pattern, has no effect on the output.

 

Since the source pattern and the clock modifier registers match up perfectly except for distortion 2 & 3, my tables only list the resulting output bitstream.

 

More information on the patterns can be found in the documentation for Ron Fries' TIASOUND emulation package.

 

However, since the output switches so fast between high and low, the resulting waveforms are not perfect squarewaves. For example distortion 4 with a pitch value of 0 would flip the output at a rate of 15720 Hz. This is so fast, that the membrane of the speaker couldn't swing very far before it has to change its direction. Therefore no audible sound is produced.

 

 

 

 

 

How to Read the Tables

Distortion

Value to be stored in the AUDCx registers.

Waveform

A 1 means the output is set high, a 0 means the output is set low. For distortion 2 & 3 it is source pattern -> clock modifier pattern.

Clockspeed

Speed at which the registers are shifted.

Pitch

Value to be stored in the AUDFx registers.

Note

Note value that is closest to the calculated frequency. (The English notation system is used here. If you are used to the German notation system, please read the 'b' notes as 'h' notes.)

Cent

Percent the calculated frequency is off its corresponding note frequency.

Freq

Frequency that this note would have if A4=440 Hz.

NTSC/PAL

Calculated frequencies for the specified TV norm.

 

Lines marked as below have such a low frequency that it really doesn't matter if it is C or C# rumble.

 

To make it easier for those who want to make music on the Atari 2600, a full size style keyboard-like image with 88 keys is provided for distortions that call for one. Pitches and the percent the pitches are off are displayed on the corresponding keys. Pitches in red are a warning that they may be too far off perfect pitch to be worth using.

 

 

 

 

 

Distortion 0 & 11

Waveform

Always high (used to output 4-bit samples by changing the volume very fast)

Clockspeed

pixelclock/114

 

 

 

 

 

Distortion 1

Waveform

001010000111011

Clockspeed

pixelclock/114

 

NTSC

PAL

Pitch

Note

Cent

Freq

NTSC

 

Pitch

Note

Cent

Freq

PAL

0 C7 +2 2093 2096   0 C7 -1 2093 2080
1 C6 +2 1046.5 1048   1 C6 -1 1046.5 1040
2 F5 0 698.5 698.7   2 F5 -1 698.5 693.3
3 C5 +2 523.3 524   3 C5 -1 523.3 520
4 G#4 +16 415.3 419.2   4 G#4 +3 415.3 416
5 F4 0 349.2 349.3   5 F4 -13 349.2 346.7
6 D4 +33 293.7 299.4   6 D4 +20 293.7 297.1
7 C4 +3 261.6 262   7 C4 -11 261.6 260
8 A#3 -2 233.1 232.9   8 A#3 -15 233.1 231.1
9 G#3 +15 207.7 209.6   9 G#3 +2 207.7 208
10 F#3 +50 185 190.5   10 F#3 +37 185 189.1
11 F3 +1 174.6 174.7   11 F3 -13 174.6 173.3
12 E3 -39 164.8 161.2   12 D#3 +48 155.6 160
13 D3 +33 146.8 149.7   13 D3 +20 146.8 148.6
14 C#3 +13 138.6 139.7   14 C#3 +1 138.6 138.7
15 C3 +3 130.8 131   15 C3 -11 130.8 130
16 B2 -3 123.5 123.3   16 B2 -16 123.5 122.4
17 A#2 0 116.4 116.4   17 A#2 -14 116.5 115.6
18 A2 +5 110 110.3   18 A2 -8 110 109.5
19 G#2 +16 103.8 104.8   19 G#2 +3 103.8 104
20 G2 +31 98 99.8   20 G2 +17 98 99
21 G2 -49 98 95.3   21 F#2 +36 92.5 94.5
22 F#2 -27 92.5 91.1   22 F#2 -40 92.5 90.4
23 F2 0 87.3 87.3   23 F2 -12 87.3 86.7
24 E2 +29 82.4 83.8   24 E2 +16 82.4 83.2
25 E2 -39 82.4 80.6   25 D#2 +48 77.8 80
26 D#2 -5 77.8 77.6   26 D#2 -18 77.8 77
27 D2 +34 73.4 74.9   27 D2 +20 73.4 74.3
28 D2 -27 73.4 72.3   28 D2 -41 73.4 71.7
29 C#2 +15 69.3 69.9   29 C#2 0 69.3 69.3
30 C#2 -44 69.3 67.6   30 C2 +44 65.4 67.1
31 C2 +3 65.4 65.5   31 C2 -11 65.4 65

 

 
 

 

 

 

 

 

Distortion 2 - 3

Waveform

001010000111011->0100000000000000000100000000000 (465 bits long)

001010000111011->0010110011111000110111010100001 (465 bits long)

Clockspeed

pixelclock/114

 

NTSC

PAL

Pitch

Note

Cent

Freq

NTSC

 

Pitch

Note

Cent

Freq

PAL

0 C#2 -44 69.3 67.6   0 C2 +44 65.4 67.1
1 C#1 -42 34.6 33.8   1 C1 +42 32.7 33.5
2 F#0 -46 23.1 22.5   2 F0 +46 21.8 22.4
3 C#0 -44 17.3 16.9   3 C0 +44 16.4 16.8
4 below     13.5   4 below     13.4
5       11.3   5       11.2
6       9.7   6       9.6
7       8.5   7       8.4
8       7.5   8       7.5
9       6.8   9       6.7
10       6.1   10       6.1
11       5.6   11       5.6
12       5.2   12       5.2
13       4.8   13       4.8
14       4.5   14       4.5
15       4.2   15       4.2
16       4   16       4
17       3.8   17       3.7
18       3.6   18       3.5
19       3.4   19       3.4
20       3.2   20       3.2
21       3.1   21       3
22       3   22       2.9
23       2.8   23       2.8
24       2.7   24       2.7
25       2.6   25       2.6
26       2.5   26       2.5
27       2.4   27       2.4
28       2.3   28       2.3
29       2.3   29       2.2
30       2.2   30       2.2
31       2.1   31     2.1

 

 

 

 

 

Distortion 4 & 5

Waveform

01

Clockspeed

pixelclock/114

 

NTSC

PAL

Pitch

Note

Cent

Freq

NTSC

 

Pitch

Note

Cent

Freq

PAL

0 silent     15720   0 silent     15600
1 B8 -9 7902.1 7860   1 B8 -23 7902.1 7800
2 E8 -11 5274 5240   2 E8 -25 5274 5200
3 B7 -10 3951.1 3930   3 B7 -23 3951.1 3900
4 G7 +4 3136 3144   4 G7 -9 3136 3120
5 E7 -11 2637 2620   5 E7 -25 2637 2600
6 C#7 +21 2217.5 2245.7   6 C#7 +8 2217.5 2228.6
7 B6 -9 1975.5 1965   7 B6 -23 1975.5 1950
8 A6 -13 1760 1746.7   8 A6 -27 1760 1733.3
9 G6 +4 1568 1572   9 G6 -9 1568 1560
10 F6 +39 1396.9 1429.1   10 F6 +25 1396.9 1418.2
11 E6 -11 1318.5 1310   11 E6 -25 1318.5 1300
12 D6 +49 1174.7 1209.2   12 D6 +36 1174.7 1200
13 C#6 +22 1108.7 1122.9   13 C#6 +8 1108.7 1114.3
14 C6 +2 1046.5 1048   14 C6 -11 1046.5 1040
15 B5 -10 987.8 982.5   15 B5 -23 987.8 975
16 A#5 -15 932.3 924.7   16 A#5 -28 932.3 917.6
17 A5 -14 880 873.3   17 A5 -27 880 866.7
18 G#5 -7 830.6 827.4   18 G#5 -20 830.6 821.1
19 G5 +4 784 786   19 G5 -9 784 780
20 F#5 +20 740 748.6   20 F#5 +7 740 742.9
21 F5 +39 698.5 714.5   21 F5 +26 698.5 709.1
22 F5 -38 698.5 683.5   22 E5 +48 659.5 678.3
23 E5 -12 659.3 655   23 E5 -25 659.3 650
24 D#5 +18 622.3 628.8   24 D#5 +5 622.3 624
25 D5 +49 587.3 604.6   25 D5 +36 587.3 600
26 D5 -16 587.3 582.2   26 D5 -29 587.3 577.8
27 C#5 +21 554.4 561.4   27 C#5 +8 554.4 557.1
28 C#5 -40 554.4 542.1   28 C5 +47 523.3 537.9
29 C5 +2 523.3 524   29 C5 -11 523.3 520
30 B4 +45 493.9 507.1   30 B4 +32 493.9 503.2
31 B4 -9 493.9 491.3   31 B4 -23 493.9 487.5

 

 
 

 

 

 

 

 

Distortion 6 & 10 - 7 & 9

Waveform

1111111111111000000000000000000 (6 & 10)

0010110011111000110111010100001 (7 & 9)

Clockspeed

pixelclock/114

 

NTSC

PAL

Pitch

Note

Cent

Freq

NTSC

 

Pitch

Note

Cent

Freq

PAL

0 B5 +45 987.8 1014.2   0 B5 +32 987.8 1006.5
1 B4 +45 493.9 507.1   1 B4 +32 493.9 503.2
2 E4 +43 329.6 338.1   2 E4 +30 329.6 335.5
3 B3 +45 246.9 253.5   3 B3 +32 246.9 251.6
4 G#3 -42 207.7 202.8   4 G3 +45 196 201.3
5 E3 +43 164.8 169   5 E3 +30 164.8 167.7
6 D3 -23 146.8 144.9   6 D3 -37 146.8 143.8
7 B2 +42 123.5 126.8   7 B2 +32 123.5 125.8
8 A2 +42 110 112.7   8 A2 +28 110 111.8
9 G#2 -41 103.8 101.4   9 G2 +45 98 100.6
10 F#2 -6 92.5 92.2   10 F#2 -19 92.5 91.5
11 E2 +43 82.4 84.5   11 E2 +31 82.4 83.9
12 D#2 +4 77.8 78   12 D#2 -9 77.8 77.4
13 D2 -24 73.4 72.4   13 D2 -37 73.4 71.9
14 C#2 -44 69.3 67.6   14 C2 +44 65.4 67.1
15 B1 +46 61.7 63.4   15 B1 +32 61.7 62.9
16 A#1 +41 58.3 59.7   16 A#1 +26 58.3 59.2
17 A1 +39 55 56.3   17 A1 +27 55 55.9
18 G#1 +48 51.9 53.4   18 G#1 +35 51.9 53
19 G#1 -41 51.9 50.7   19 G1 +45 49 50.3
20 G1 -25 49 48.3   20 G1 -39 49 47.9
21 F#1 -4 46.2 46.1   21 F#1 -20 46.2 45.7
22 F1 +16 43.7 44.1   22 F1 +4 43.7 43.8
23 E1 +44 41.2 42.3   23 E1 +28 41.2 41.9
24 E1 -26 41.2 40.6   24 E1 -39 41.2 40.3
25 D#1 +4 38.9 39   25 D#1 -9 38.9 38.7
26 D1 +41 36.7 37.6   26 D1 +27 36.7 37.3
27 D1 -24 36.7 36.2   27 D1 -38 36.7 35.9
28 C#1 +19 34.6 35   28 C#1 +5 34.6 34.7
29 C#1 -42 34.6 33.8   29 C1 +42 32.7 33.5
30 C1 0 32.7 32.7   30 C1 -11 32.7 32.5
31 B0 +44 30.9 31.7   31 B0 +33 30.9 31.5

 

 
 

 

 

 

 

 

Distortion 8

Waveform

511 bits long (white noise)

Clockspeed

pixelclock/114

 

NTSC

PAL

Pitch

Note

Cent

Freq

NTSC

 

Pitch

Note

Cent

Freq

PAL

0 B1 -6 61.7 61.5   0 B1 -18 61.7 61.1
1 B0 -6 30.9 30.8   1 B0 -22 30.9 30.5
2 E0 -8 20.6 20.5   2 E0 -17 20.6 20.4
3 below     15.4   3 below     15.3
4       12.3   4       12.2
5       10.3   5       10.2
6       8.8   6       8.7
7       7.7   7       7.6
8       6.8   8       6.8
9       6.2   9       6.1
10       5.6   10       5.6
11       5.1   11       5.1
12       4.7   12       4.7
13       4.4   13       4.4
14       4.1   14       4.1
15       3.8   15       3.8
16       3.6   16       3.6
17       3.4   17       3.4
18       3.2   18       3.2
19       3.1   19       3.1
20       2.9   20       2.9
21       2.8   21       2.8
22       2.7   22       2.7
23       2.6   23       2.5
24       2.5   24       2.4
25       2.4   25       2.3
26       2.3   26       2.3
27       2.2   27       2.2
28       2.1   28       2.1
29       2   29       2
30       2   30       2
31       1.9   31     1.9

 

 

 

 

 

Distortion 12 & 13

Waveform

10

Clockspeed

CPUclock/114

 

NTSC

PAL

Pitch

Note

Cent

Freq

NTSC

 

Pitch

Note

Cent

Freq

PAL

0 E8 -11 5274 5240   0 E8 -25 5274 5200
1 E7 -11 2637 2620   1 E7 -25 2637 2600
2 A6 -14 1760 1746.6   2 A6 -27 1760 1733.3
3 E6 -11 1318.5 1310   3 E6 -25 1318.5 1300
4 C6 +2 1046.5 1048   4 C6 -11 1046.5 1040
5 A5 -14 880 873.3   5 A5 -27 880 866.7
6 F#5 +20 740 748.6   6 F#5 +7 740 742.9
7 E5 -12 659.3 655   7 E5 -25 659.3 650
8 D5 -16 587.3 582.2   8 D5 -29 587.3 577.8
9 C5 +2 523.3 524   9 C5 -11 523.3 520
10 A#4 +39 466.2 476.4   10 A#4 +23 466.2 472.7
11 A4 -13 440 436.7   11 A4 -27 440 433.3
12 G4 +48 392 403.1   12 G4 +34 392 400
13 F#4 +20 370 374.3   13 F#4 +6 370 371.4
14 F4 0 349.2 349.3   14 F4 -13 349.2 346.7
15 E4 -11 329.6 327.5   15 E4 -25 329.6 325
16 D#4 -17 311.1 308.2   16 D#4 -30 311.1 305.9
17 D4 -16 293.7 291.1   17 D4 -29 293.7 288.9
18 C#4 -9 277.2 275.8   18 C#4 -22 277.2 273.7
19 C4 +3 261.6 262   19 C4 -11 261.6 260
20 B3 +18 246.9 249.5   20 B3 +5 246.9 247.6
21 A#3 +37 233.1 238.2   21 A#3 +24 233.1 236.4
22 A#3 -40 233.1 227.8   22 A3 +47 220 226.1
23 A3 -14 220 218.3   23 A3 -27 220 216.7
24 G#3 +15 207.7 209.6   24 G#3 +2 207.7 208
25 G3 +47 196 201.5   25 G3 +34 196 200
26 G3 -17 196 194.1   26 G3 -31 196 192.6
27 F#3 +19 185 187.1   27 F#3 +6 185 185.7
28 F#3 -41 185 180.7   28 F3 +45 174.6 179.3
29 F3 +1 174.6 174.7   29 F3 -13 174.6 173.3
30 E3 +43 164.8 169   30 E3 +30 164.8 167.7
31 E3 -11 164.8 163.8   31 E3 -25 164.8 162.5

 

 
 

 

 

 

 

 

Distortion 14 - 15

Waveform

1111111111111000000000000000000 (14)

0010110011111000110111010100001 (15)

Clockspeed

CPUclock/114

 

NTSC

PAL

Pitch

Note

Cent

Freq

NTSC

 

Pitch

Note

Cent

Freq

PAL

0 E4 +43 329.6 338.1   0 E4 +30 329.6 335.5
1 E3 +43 164.8 169   1 E3 +30 164.8 167.7
2 A2 +42 110 112.7   2 A2 +28 110 111.8
3 E2 +43 82.4 84.5   3 E2 +31 82.4 83.9
4 C#2 -44 69.3 67.6   4 C2 +44 65.4 67.1
5 A1 +39 55 56.3   5 A1 +27 55 55.9
6 G1 -25 49 48.3   6 G1 -39 49 47.9
7 E1 +44 41.2 42.3   7 E1 +28 41.2 41.9
8 D1 +41 36.7 37.6   8 D1 +27 36.7 37.3
9 C#1 -42 34.6 33.8   9 C1 +42 32.7 33.5
10 B0 -11 30.9 30.7   10 B0 -22 30.9 30.5
11 A0 +44 27.5 28.2   11 A0 +31 27.5 28
12 G#0 0 26 26   12 G#0 -13 26 25.8
13 G0 -29 24.5 24.1   13 G0 -36 24.5 24
14 F#0 -46 23.1 22.5   14 F0 +46 21.8 22.4
15 E0 +42 20.6 21.1   15 E0 +33 20.6 21
16 D#0 +42 19.4 19.9   16 D#0 +25 19.4 19.7
17 D0 +40 18.4 18.8   17 D0 +20 18.4 18.6
18 C#0 +45 17.3 17.8   18 C#0 +36 17.3 17.7
19 C#0 -44 17.3 16.9   19 C0 +44 16.4 16.8
20 C0 -30 16.4 16.1   20 C0 -40 16.4 16
21 below     15.4   21 below     15.2
22       14.7   22       14.6
23       14.1   23       14
24       13.5   24       13.4
25       13   25       12.9
26       12.5   26       12.4
27       12.1   27       12
28       11.7   28       11.6
29       11.3   29       11.2
30       10.9   30       10.8
31       10.6   31     10.5

 

 
 

 

 

 

 

 

Keyboards Only

 

4  (Pure)

 

 

 

12  (Pure Lower)

 

 

 

1  (Buzzy)

 

 

 

6 or 7  (Pure/Buzzy/Reedy/Rumble)

 

 

 

14  (Electronic/Rumble)

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View this page and any external web sites at your own risk. I am not responsible for any possible spiritual, emotional, physical, financial or any other damage to you, your friends, family, ancestors, or descendants in the past, present, or future, living or dead, in this dimension or any other.

 

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