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-rw-r--r--src/lib/formats/camplynx_cas.cpp220
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diff --git a/src/lib/formats/camplynx_cas.cpp b/src/lib/formats/camplynx_cas.cpp
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+// 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