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author Miodrag Milanovic <mmicko@gmail.com>2015-11-08 12:56:12 +0100
committer Miodrag Milanovic <mmicko@gmail.com>2015-11-08 12:56:12 +0100
commit7c19aac60e12d6f5ea301bdb34d7826a01e0b06f (patch)
treef310d86aa2c6bfc19d115307dedde4eb0cd52dad /src/lib/formats/mbee_cas.cpp
parenta57b46ae933badd7441ce1644711dbb851e2b504 (diff)
Rename *.c -> *.cpp in our source (nw)
Diffstat (limited to 'src/lib/formats/mbee_cas.cpp')
-rw-r--r--src/lib/formats/mbee_cas.cpp261
1 files changed, 261 insertions, 0 deletions
diff --git a/src/lib/formats/mbee_cas.cpp b/src/lib/formats/mbee_cas.cpp
new file mode 100644
index 00000000000..fe0a2ffbc24
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+++ b/src/lib/formats/mbee_cas.cpp
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+// license:BSD-3-Clause
+// copyright-holders:Robbbert
+/********************************************************************
+
+Support for Microbee cassette images
+
+Microbee tapes consist of 3 sections
+1. A leader of 63 zeroes
+2. A header which contains the program name and other info
+3. The main program
+
+Each byte after conversion becomes a start bit, bit 0,1,etc to 7,
+then 2 stop bits.
+
+At 1200 baud, a high = 2 cycles of 2400Hz and a low = 1 cycle of 1200Hz
+At 300 baud, a high = 8 cycles of 2400Hz and a low = 4 cycles of 1200Hz
+
+The header bytes are arranged thus:
+1 (SOH) 0x01
+6 File name
+1 file type (M=machine language, B=Basic)
+2 length
+2 load address
+2 exec address
+1 tape speed (0 = 300 baud; other = 1200 baud)
+1 auto-start (0 = no)
+1 unassigned byte
+1 CRC byte
+
+The header is always at 300 baud; the program will be at the
+speed indicated by the speed byte.
+
+By coincidence (or not), the header is the same format as that
+of the Sorcerer and SOL-20. In these, the speed and auto-start
+bytes are unassigned. The CRC uses the same algorithm.
+
+The main program is broken into blocks of 256, with each block
+having its own CRC byte.
+
+Microbee tape and quickload formats:
+
+BEE - straight binary dump to address 0900, no header. For Machine
+ Language programs.
+
+BIN - the standard z80bin format.
+
+COM - straight binary dump to address 0100, no header. For Machine
+ Language programs.
+
+MWB - straight binary dump to address 08C0, no header. For BASIC
+ programs.
+
+TAP - has an ID header of TAP_DGOS_BEE or MBEE, null terminated.
+ This is followed by the binary dump with the leader and CRC
+ bytes included.
+
+********************************************************************/
+
+#include <assert.h>
+
+#include "mbee_cas.h"
+
+#define WAVEENTRY_LOW -32768
+#define WAVEENTRY_HIGH 32767
+
+#define MBEE_WAV_FREQUENCY 9600
+
+// image size
+static int mbee_image_size;
+static bool mbee_speed;
+
+static int mbee_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 mbee_output_bit(INT16 *buffer, int sample_pos, bool bit)
+{
+ int samples = 0;
+ if (mbee_speed)
+ {
+ if (bit)
+ {
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH);
+ }
+ else
+ {
+ samples += mbee_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_HIGH);
+ }
+ }
+ else
+ {
+ if (bit)
+ {
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 2, WAVEENTRY_HIGH);
+ }
+ else
+ {
+ samples += mbee_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_HIGH);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_HIGH);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_HIGH);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_LOW);
+ samples += mbee_put_samples(buffer, sample_pos + samples, 4, WAVEENTRY_HIGH);
+ }
+ }
+
+ return samples;
+}
+
+static int mbee_output_byte(INT16 *buffer, int sample_pos, UINT8 byte)
+{
+ int samples = 0;
+ UINT8 i;
+
+ /* start */
+ samples += mbee_output_bit (buffer, sample_pos + samples, 0);
+
+ /* data */
+ for (i = 0; i<8; i++)
+ samples += mbee_output_bit (buffer, sample_pos + samples, (byte >> i) & 1);
+
+ /* stop */
+ for (i = 0; i<2; i++)
+ samples += mbee_output_bit (buffer, sample_pos + samples, 1);
+
+ return samples;
+}
+
+static int mbee_handle_tap(INT16 *buffer, const UINT8 *bytes)
+{
+ UINT32 sample_count = 0;
+ UINT32 byte_count = 0;
+ UINT32 i = 0;
+ bool temp_speed = 0;
+ UINT8 temp_blocks = 0;
+ UINT16 temp_size = 0;
+
+ // TAP file starts with a null-terminate ID string. We just skip this.
+ while (bytes[byte_count])
+ byte_count++;
+
+ // there can be a library of files, loop through them all
+ while (byte_count < mbee_image_size)
+ {
+ mbee_speed = 0;
+
+ // now output the leader
+ while ( (!bytes[byte_count]) && (byte_count < mbee_image_size) )
+ sample_count += mbee_output_byte(buffer, sample_count, bytes[byte_count++]);
+
+ // make sure SOH is where we expect
+ if (bytes[byte_count] != 1 )
+ break;
+
+ // store the size for later
+ temp_blocks = bytes[byte_count + 9];
+ temp_size = bytes[byte_count + 8] + temp_blocks*256;
+
+ // store the speed for later
+ temp_speed = (bytes[byte_count + 15]) ? 1 : 0;
+
+ /* header */
+ for (i=0; i<18; i++)
+ sample_count += mbee_output_byte(buffer, sample_count, bytes[byte_count++]);
+
+ // change speed
+ mbee_speed = temp_speed;
+
+ // calculate size of program including CRC bytes
+ temp_size = temp_size + temp_blocks + 1;
+
+ /* data */
+ for (i=0; i<temp_size; i++)
+ sample_count += mbee_output_byte(buffer, sample_count, bytes[byte_count++]);
+
+ }
+
+ return sample_count;
+}
+
+
+/*******************************************************************
+ Generate samples for the tape image
+********************************************************************/
+
+static int mbee_tap_fill_wave(INT16 *buffer, int length, UINT8 *bytes)
+{
+ return mbee_handle_tap(buffer, bytes);
+}
+
+/*******************************************************************
+ Calculate the number of samples needed for this tape image
+********************************************************************/
+
+static int mbee_tap_calculate_size_in_samples(const UINT8 *bytes, int length)
+{
+ mbee_image_size = length;
+
+ return mbee_handle_tap(NULL, bytes);
+}
+
+static const struct CassetteLegacyWaveFiller mbee_tap_config =
+{
+ mbee_tap_fill_wave, /* fill_wave */
+ -1, /* chunk_size */
+ 0, /* chunk_samples */
+ mbee_tap_calculate_size_in_samples, /* chunk_sample_calc */
+ MBEE_WAV_FREQUENCY, /* sample_frequency */
+ 0, /* header_samples */
+ 0 /* trailer_samples */
+};
+
+static casserr_t mbee_tap_identify(cassette_image *cassette, struct CassetteOptions *opts)
+{
+ return cassette_legacy_identify(cassette, opts, &mbee_tap_config);
+}
+
+static casserr_t mbee_tap_load(cassette_image *cassette)
+{
+ return cassette_legacy_construct(cassette, &mbee_tap_config);
+}
+
+static const struct CassetteFormat mbee_tap_image_format =
+{
+ "tap",
+ mbee_tap_identify,
+ mbee_tap_load,
+ NULL
+};
+
+CASSETTE_FORMATLIST_START(mbee_cassette_formats)
+ CASSETTE_FORMAT(mbee_tap_image_format)
+CASSETTE_FORMATLIST_END