# The Line - Soviet and Russian exchange tones after GOST 28384-89 and ITU-T E.180 - https://lab.glossema.dev/play/the-line
# grid: unit 1000ms, bar 3000ms
# Dial, ringing and busy tones at 425 Hz; special information tone at 950, 1400 and 1800 Hz.
# Dial: 2000 ms of tone, 1000 ms of silence. Ringing: 1000 ms on, 4000 ms off.
# Busy: 350 ms on, 350 ms off. Special information: 333 ms per tone, no gap, then 999 ms off.
# Three calls: nobody answers, the line is busy, the call cannot go through.
# 15 bars, 34194 ms.

# ---- call 1 of 3: nobody answers ----
:put "Dial tone";
# bar 1
:beep frequency=425 length=2000ms;  # dial 425 Hz
:delay 2000ms;
:delay 1000ms;                      # dial, silent

:put "Ringing tone";
# grid: unit 1000ms, bar 5000ms
# bar 2
:beep frequency=425 length=1000ms;  # ringing 425 Hz
:delay 1000ms;
:delay 4000ms;                      # ringing, silent

# bar 3
:beep frequency=425 length=1000ms;  # ringing 425 Hz
:delay 1000ms;
:delay 4000ms;                      # ringing, silent

# bar 4
:beep frequency=425 length=1000ms;  # ringing 425 Hz
:delay 1000ms;
:delay 4000ms;                      # ringing, silent

# ---- call 2 of 3: busy ----
:put "Dial tone";
# grid: unit 1000ms, bar 3000ms
# bar 5
:beep frequency=425 length=2000ms;  # dial 425 Hz
:delay 2000ms;
:delay 1000ms;                      # dial, silent

:put "Busy tone";
# grid: unit 350ms, bar 700ms
# bar 6
:beep frequency=425 length=350ms;   # busy 425 Hz
:delay 350ms;
:delay 350ms;                       # busy, silent

# bar 7
:beep frequency=425 length=350ms;   # busy 425 Hz
:delay 350ms;
:delay 350ms;                       # busy, silent

# bar 8
:beep frequency=425 length=350ms;   # busy 425 Hz
:delay 350ms;
:delay 350ms;                       # busy, silent

# bar 9
:beep frequency=425 length=350ms;   # busy 425 Hz
:delay 350ms;
:delay 350ms;                       # busy, silent

# bar 10
:beep frequency=425 length=350ms;   # busy 425 Hz
:delay 350ms;
:delay 350ms;                       # busy, silent

# bar 11
:beep frequency=425 length=350ms;   # busy 425 Hz
:delay 350ms;
:delay 350ms;                       # busy, silent

# ---- call 3 of 3: the call cannot go through ----
:put "Dial tone";
# grid: unit 1000ms, bar 3000ms
# bar 12
:beep frequency=425 length=2000ms;  # dial 425 Hz
:delay 2000ms;
:delay 1000ms;                      # dial, silent

:put "Special information tone";
# grid: unit 333ms, bar 1998ms
# bar 13
:beep frequency=950 length=333ms;   # special information 950 Hz
:delay 333ms;
:beep frequency=1400 length=333ms;  # special information 1400 Hz
:delay 333ms;
:beep frequency=1800 length=333ms;  # special information 1800 Hz
:delay 333ms;
:delay 999ms;                       # special information, silent

# bar 14
:beep frequency=950 length=333ms;   # special information 950 Hz
:delay 333ms;
:beep frequency=1400 length=333ms;  # special information 1400 Hz
:delay 333ms;
:beep frequency=1800 length=333ms;  # special information 1800 Hz
:delay 333ms;
:delay 999ms;                       # special information, silent

# bar 15
:beep frequency=950 length=333ms;   # special information 950 Hz
:delay 333ms;
:beep frequency=1400 length=333ms;  # special information 1400 Hz
:delay 333ms;
:beep frequency=1800 length=333ms;  # special information 1800 Hz
:delay 333ms;
:delay 999ms;                       # special information, silent