diff options
author | 2015-11-08 12:56:12 +0100 | |
---|---|---|
committer | 2015-11-08 12:56:12 +0100 | |
commit | 7c19aac60e12d6f5ea301bdb34d7826a01e0b06f (patch) | |
tree | f310d86aa2c6bfc19d115307dedde4eb0cd52dad /src/lib/formats/camplynx_cas.cpp | |
parent | a57b46ae933badd7441ce1644711dbb851e2b504 (diff) |
Rename *.c -> *.cpp in our source (nw)
Diffstat (limited to 'src/lib/formats/camplynx_cas.cpp')
-rw-r--r-- | src/lib/formats/camplynx_cas.cpp | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/src/lib/formats/camplynx_cas.cpp b/src/lib/formats/camplynx_cas.cpp new file mode 100644 index 00000000000..a525f18d3cb --- /dev/null +++ b/src/lib/formats/camplynx_cas.cpp @@ -0,0 +1,220 @@ +// license:BSD-3-Clause +// copyright-holders:Robbbert +/******************************************************************** + +Support for Camputers Lynx cassette images + + +We support TAP files used by the Pale and Jynx emulators. + +Tape format: +- about 7 seconds of zeroes +- A5 byte +- 22 byte +- program name +- 22 byte +- about 7 seconds of zeroes +- A5 byte +- header +- main program +- checksum + +Each byte is 8 bits (MSB first) with no start or stop bits. + +********************************************************************/ + +#include "emu.h" // for popmessage and <string> + +#include "camplynx_cas.h" + +#define WAVEENTRY_LOW -32768 +#define WAVEENTRY_HIGH 32767 + +#define LYNX48K_WAV_FREQUENCY 4000 +#define LYNX128K_WAV_FREQUENCY 8000 + + +// image size +static int camplynx_image_size; + +static int camplynx_put_samples(INT16 *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 camplynx_output_bit(INT16 *buffer, int sample_pos, bool bit) +{ + int samples = 0; + + if (bit) + { + samples += camplynx_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_HIGH); + samples += camplynx_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_LOW); + } + else + { + samples += camplynx_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH); + samples += camplynx_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW); + } + + return samples; +} + +static int camplynx_output_byte(INT16 *buffer, int sample_pos, UINT8 byte) +{ + int samples = 0; + UINT8 i; + + /* data */ + for (i = 0; i<8; i++) + samples += camplynx_output_bit (buffer, sample_pos + samples, (byte >> (7-i)) & 1); + + return samples; +} + +static int camplynx_handle_cassette(INT16 *buffer, const UINT8 *bytes) +{ + UINT32 sample_count = 0; + UINT32 byte_count = 0; + UINT32 i; + + /* header zeroes */ + for (i=0; i<555; i++) + sample_count += camplynx_output_byte(buffer, sample_count, 0); + + if (bytes[0] == 0x22) + { + std::string pgmname = " LOAD \""; + byte_count++; + sample_count += camplynx_output_byte(buffer, sample_count, 0xA5); + sample_count += camplynx_output_byte(buffer, sample_count, 0x22); + + /* program name - include protection in case tape is corrupt */ + for (i=1; bytes[i]!=0x22; i++) + { + if (i < camplynx_image_size) + { + sample_count += camplynx_output_byte(buffer, sample_count, bytes[i]); + pgmname.append(1, (char)bytes[i]); + } + else + return sample_count; + byte_count++; + } + + pgmname.append(1, (char)0x22); + sample_count += camplynx_output_byte(buffer, sample_count, bytes[byte_count++]); // should be 0x22 + + // if a machine-language program, say to use MLOAD + if (bytes[byte_count] == 0x4D) + pgmname[0] = (char)0x4D; + + // Tell user how to load the tape + osd_printf_info("%s",pgmname.c_str()); + + /* data zeroes */ + for (i=0; i<555; i++) + sample_count += camplynx_output_byte(buffer, sample_count, 0); + + sample_count += camplynx_output_byte(buffer, sample_count, 0xA5); + } + + /* data */ + for (i=byte_count; i<camplynx_image_size; i++) + sample_count += camplynx_output_byte(buffer, sample_count, bytes[i]); + + return sample_count; +} + + +/******************************************************************* + Generate samples for the tape image +********************************************************************/ + +static int camplynx_cassette_fill_wave(INT16 *buffer, int length, UINT8 *bytes) +{ + return camplynx_handle_cassette(buffer, bytes); +} + +/******************************************************************* + Calculate the number of samples needed for this tape image +********************************************************************/ + +static int camplynx_cassette_calculate_size_in_samples(const UINT8 *bytes, int length) +{ + camplynx_image_size = length; + + return camplynx_handle_cassette(NULL, bytes); +} + +static const struct CassetteLegacyWaveFiller lynx48k_legacy_fill_wave = +{ + camplynx_cassette_fill_wave, /* fill_wave */ + -1, /* chunk_size */ + 0, /* chunk_samples */ + camplynx_cassette_calculate_size_in_samples, /* chunk_sample_calc */ + LYNX48K_WAV_FREQUENCY, /* sample_frequency */ + 0, /* header_samples */ + 0 /* trailer_samples */ +}; + +static const struct CassetteLegacyWaveFiller lynx128k_legacy_fill_wave = +{ + camplynx_cassette_fill_wave, /* fill_wave */ + -1, /* chunk_size */ + 0, /* chunk_samples */ + camplynx_cassette_calculate_size_in_samples, /* chunk_sample_calc */ + LYNX128K_WAV_FREQUENCY, /* sample_frequency */ + 0, /* header_samples */ + 0 /* trailer_samples */ +}; + +static casserr_t lynx48k_cassette_identify(cassette_image *cassette, struct CassetteOptions *opts) +{ + return cassette_legacy_identify(cassette, opts, &lynx48k_legacy_fill_wave); +} + +static casserr_t lynx128k_cassette_identify(cassette_image *cassette, struct CassetteOptions *opts) +{ + return cassette_legacy_identify(cassette, opts, &lynx128k_legacy_fill_wave); +} + +static casserr_t lynx48k_cassette_load(cassette_image *cassette) +{ + return cassette_legacy_construct(cassette, &lynx48k_legacy_fill_wave); +} + +static casserr_t lynx128k_cassette_load(cassette_image *cassette) +{ + return cassette_legacy_construct(cassette, &lynx128k_legacy_fill_wave); +} + +static const struct CassetteFormat lynx48k_cassette_image_format = +{ + "tap", + lynx48k_cassette_identify, + lynx48k_cassette_load, + NULL +}; + +static const struct CassetteFormat lynx128k_cassette_image_format = +{ + "tap", + lynx128k_cassette_identify, + lynx128k_cassette_load, + NULL +}; + +CASSETTE_FORMATLIST_START(lynx48k_cassette_formats) + CASSETTE_FORMAT(lynx48k_cassette_image_format) +CASSETTE_FORMATLIST_END + +CASSETTE_FORMATLIST_START(lynx128k_cassette_formats) + CASSETTE_FORMAT(lynx128k_cassette_image_format) +CASSETTE_FORMATLIST_END |