diff options
Diffstat (limited to 'src/lib/formats/h8_cas.cpp')
-rw-r--r-- | src/lib/formats/h8_cas.cpp | 171 |
1 files changed, 60 insertions, 111 deletions
diff --git a/src/lib/formats/h8_cas.cpp b/src/lib/formats/h8_cas.cpp index c0d5d6dd925..526e411d5ae 100644 --- a/src/lib/formats/h8_cas.cpp +++ b/src/lib/formats/h8_cas.cpp @@ -1,147 +1,96 @@ // license:BSD-3-Clause -// copyright-holders:Robbbert +// copyright-holders:Robbbert,Mark Garlanger /******************************************************************** -Support for Heathkit H8 H8T cassette images +Support for Heathkit H8/H88 H8T cassette images Standard Kansas City format (300 baud) +TODO - investigate 1200 buad support, H8 should support it, but H88 does not. + We output a leader, followed by the contents of the H8T file. ********************************************************************/ #include "h8_cas.h" -#define WAVEENTRY_LOW -32768 -#define WAVEENTRY_HIGH 32767 - -#define H8_WAV_FREQUENCY 9600 - -// image size -static int h8_image_size; // FIXME: global variable prevents multiple instances - -static int h8_put_samples(int16_t *buffer, int sample_pos, int count, int level) -{ - if (buffer) - { - for (int i=0; i<count; i++) - buffer[sample_pos + i] = level; - } - - return count; -} - -static int h8_output_bit(int16_t *buffer, int sample_pos, bool bit) -{ - int samples = 0; - - for (uint8_t i = 0; i < 4; i++) - { - if (bit) - { - samples += h8_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW); - samples += h8_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH); - samples += h8_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW); - samples += h8_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH); - } - else - { - samples += h8_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_LOW); - samples += h8_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_HIGH); - } - } - - return samples; -} - -static int h8_output_byte(int16_t *buffer, int sample_pos, uint8_t byte) -{ - int samples = 0; - uint8_t i; +#include "coretmpl.h" // BIT - // start bit - samples += h8_output_bit (buffer, sample_pos + samples, 0); - // data bits - for (i = 0; i<8; i++) - samples += h8_output_bit (buffer, sample_pos + samples, (byte >> i) & 1); +namespace { - // stop bits - for (i = 0; i<2; i++) - samples += h8_output_bit (buffer, sample_pos + samples, 1); - - return samples; -} +constexpr double ONE_FREQ = 1200.0; +constexpr double ONE_FREQ_VARIANCE = 300.0; +constexpr double ZERO_FREQ = 2400.0; +constexpr double ZERO_FREQ_VARIANCE = 600.0; -static int h8_handle_cassette(int16_t *buffer, const uint8_t *bytes) +const cassette_image::Modulation heath_h8t_modulation = { - uint32_t sample_count = 0; - uint32_t byte_count = 0; - uint32_t i; - - - // leader - for (i=0; i<2000; i++) - sample_count += h8_output_bit(buffer, sample_count, 1); - - // data - for (i=byte_count; i<h8_image_size; i++) - sample_count += h8_output_byte(buffer, sample_count, bytes[i]); - - return sample_count; -} - - -/******************************************************************* - Generate samples for the tape image -********************************************************************/ + cassette_image::MODULATION_SINEWAVE, + ONE_FREQ - ONE_FREQ_VARIANCE, ONE_FREQ, ONE_FREQ + ONE_FREQ_VARIANCE, + ZERO_FREQ - ZERO_FREQ_VARIANCE, ZERO_FREQ, ZERO_FREQ + ZERO_FREQ_VARIANCE +}; -static int h8_cassette_fill_wave(int16_t *buffer, int length, uint8_t *bytes) +cassette_image::error heath_h8t_identify(cassette_image *cassette, cassette_image::Options *opts) { - return h8_handle_cassette(buffer, bytes); + return cassette->modulation_identify(heath_h8t_modulation, opts); } -/******************************************************************* - Calculate the number of samples needed for this tape image -********************************************************************/ -static int h8_cassette_calculate_size_in_samples(const uint8_t *bytes, int length) +cassette_image::error heath_h8t_load(cassette_image *cassette) { - h8_image_size = length; + cassette_image::error err = cassette_image::error::SUCCESS; + uint64_t image_size = cassette->image_size(); + double time_index = 0.0; + double time_displacement; + + auto const MODULATE = + [&cassette, &err, &time_index, &time_displacement] (unsigned value) + { + for (int i = 0; (i < (value ? 8 : 4)); i++) + { + err = cassette->put_modulated_data_bit(0, time_index, value, heath_h8t_modulation, &time_displacement); + if (cassette_image::error::SUCCESS == err) + time_index += time_displacement; + else + return; + } + }; + + // leader - 1 second + while ((cassette_image::error::SUCCESS == err) && (time_index < 1.0)) + MODULATE(1); + + for (uint64_t image_pos = 0; (cassette_image::error::SUCCESS == err) && (image_pos < image_size); image_pos++) + { + uint8_t data = cassette->image_read_byte(image_pos); - return h8_handle_cassette(nullptr, bytes); -} + // start bit + MODULATE(0); -static const cassette_image::LegacyWaveFiller h8_legacy_fill_wave = -{ - h8_cassette_fill_wave, // fill_wave - -1, // chunk_size - 0, // chunk_samples - h8_cassette_calculate_size_in_samples, // chunk_sample_calc - H8_WAV_FREQUENCY, // sample_frequency - 0, // header_samples - 0 // trailer_samples -}; + // data bits + for (int bit = 0; (cassette_image::error::SUCCESS == err) && (bit < 8); bit++) + MODULATE(util::BIT(data, bit)); -static cassette_image::error h8_cassette_identify(cassette_image *cassette, cassette_image::Options *opts) -{ - return cassette->legacy_identify(opts, &h8_legacy_fill_wave); -} + // stop bit + if (cassette_image::error::SUCCESS == err) + MODULATE(1); + } -static cassette_image::error h8_cassette_load(cassette_image *cassette) -{ - return cassette->legacy_construct(&h8_legacy_fill_wave); + return err; } -static const cassette_image::Format h8_cassette_image_format = +const cassette_image::Format heath_h8t_format = { "h8t", - h8_cassette_identify, - h8_cassette_load, + heath_h8t_identify, + heath_h8t_load, nullptr }; -CASSETTE_FORMATLIST_START(h8_cassette_formats) - CASSETTE_FORMAT(h8_cassette_image_format) +} + +CASSETTE_FORMATLIST_START( h8_cassette_formats ) + CASSETTE_FORMAT( heath_h8t_format ) CASSETTE_FORMATLIST_END |