From 9cf2ca6453eb2f07342ef3beb92e82780abded01 Mon Sep 17 00:00:00 2001 From: Wolfgang Hottgenroth Date: Mon, 3 Jun 2024 15:31:06 +0200 Subject: [PATCH] changes --- docs/calc-76489an.py | 64 ++++++++++++++++++++++++++++++++++++++++++++ psg.c | 12 +++++++-- psg.h | 2 +- 3 files changed, 75 insertions(+), 3 deletions(-) create mode 100644 docs/calc-76489an.py diff --git a/docs/calc-76489an.py b/docs/calc-76489an.py new file mode 100644 index 0000000..e8ef518 --- /dev/null +++ b/docs/calc-76489an.py @@ -0,0 +1,64 @@ +N = 3579545.0 +factor = 1.0594631 +base = 440.0 + +frequencies = [] + +BEFORE_A = 46 +f = base +for i in range (BEFORE_A): + idx = BEFORE_A - i - 1 + print(f"{idx}: {f}") + frequencies.append(f) + f = base / factor + base = f +frequencies.reverse() + +AFTER_A = 50 +base = 440.0 +for i in range(AFTER_A): + idx = BEFORE_A + i + f = base * factor + print(f"{idx}: {f}") + frequencies.append(f) + base = f + +# print(f"{frequencies}") + +codes = [] +for i in range(len(frequencies)): + codes.append(round(N / (32.0 * frequencies[i]))) + + +#const uint16_t frequencyCodes[8][12] = { +# // C, Cis, D, Dis, E, F, Fis, G, Gis, A, Ais, H +# { 06535, 06234, 05747, 05474, 05233, 05002, 04563, 04353, 04153, 03762, 03600, 03424 }, // Octave 1 +# { 03256, 03116, 02764, 02636, 02515, 02401, 02271, 02165, 02065, 01771, 01700, 01612 }, // Octave 2 +# { 01527, 01447, 01372, 01317, 01247, 01201, 01135, 01073, 01033, 00774, 00740, 00705 }, // Octave 3 +# { 00654, 00624, 00575, 00550, 00523, 00500, 00456, 00435, 00415, 00376, 00360, 00342 }, // Octave 4 +# { 00326, 00312, 00276, 00264, 00252, 00240, 00227, 00217, 00207, 00177, 00170, 00161 }, // Octave 5 +# { 00153, 00145, 00137, 00132, 00125, 00120, 00114, 00107, 00103, 00100, 00074, 00071 }, // Octave 6 +# { 00065, 00062, 00060, 00055, 00052, 00050, 00046, 00044, 00042, 00040, 00036, 00034 }, // Octave 7 +# { 00033, 00031, 00030, 00026, 00025, 00024, 00023, 00022, 00021, 00020, 00017, 00016 } // Octave 8 +#}; + + + +print("const uint16_t frequencyCodes[8][12] = {") +step = 12 +for i in range(len(codes)): + if (i % step == 0): + print(" { ", end='') + print(f"{codes[i]}", end='') + if ((i+1) % step != 0): + print(", ", end='') + if ((i+1) % step == 0): + print(" }", end='') + if ((i+1) != len(codes)): + print(", ") + else: + print() +print("};") + + + diff --git a/psg.c b/psg.c index dd387a5..57d2ca7 100644 --- a/psg.c +++ b/psg.c @@ -6,6 +6,8 @@ #include "scheduler.h" +const uint32_t BASE_FREQUENCY = 3579545; + // based on 3.579545 MHz const uint16_t frequencyCodes[8][12] = { { 3420, 3229, 3047, 2876, 2715, 2562, 2419, 2283, 2155, 2034, 1920, 1812 }, @@ -76,7 +78,7 @@ inline static void WRITE_CYCLE(uint8_t chipNo) { // WRITE_CYCLE(chipNo); //} -static void psgWriteFrequency(uint8_t chip, uint8_t channel, uint16_t frequencyCode) { +static void psgWriteFrequencyCode(uint8_t chip, uint8_t channel, uint16_t frequencyCode) { uint8_t chipNo = chip; uint8_t regAddr = (channel % 3) * 2; @@ -132,10 +134,16 @@ void psgPlayTone(uint8_t chip, uint8_t channel, uint8_t volume, t_octave octave, psgAmplitude(chip, channel, 0); } else { psgAmplitude(chip, channel, volume); - psgWriteFrequency(chip, channel, frequencyCodes[octave][note]); + psgWriteFrequencyCode(chip, channel, frequencyCodes[octave][note]); } } +void psgPlayFrequency(uint8_t chip, uint8_t channel, uint8_t volume, uint16_t frequency) { + uint16_t frequencyCode = BASE_FREQUENCY / (32 * frequency); + psgAmplitude(chip, channel, volume); + psgWriteFrequencyCode(chip, channel, frequencyCode); +} + void psgInit() { // address/data bus P2DIR = 0xff; diff --git a/psg.h b/psg.h index 79bcda9..9171484 100644 --- a/psg.h +++ b/psg.h @@ -41,6 +41,6 @@ void psgInit(); void psgPlayTone(uint8_t chip, uint8_t channel, uint8_t volume, t_octave octave, t_note note); void psgAmplitude(uint8_t chip, uint8_t channel, uint8_t volume); - +void psgPlayFrequency(uint8_t chip, uint8_t channel, uint8_t volume, uint16_t frequency); #endif // _PSG_H_