summaryrefslogtreecommitdiffstatshomepage
path: root/src/lib/formats/sc3000_bit.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/lib/formats/sc3000_bit.cpp')
-rw-r--r--src/lib/formats/sc3000_bit.cpp106
1 files changed, 106 insertions, 0 deletions
diff --git a/src/lib/formats/sc3000_bit.cpp b/src/lib/formats/sc3000_bit.cpp
new file mode 100644
index 00000000000..2b5fd635db5
--- /dev/null
+++ b/src/lib/formats/sc3000_bit.cpp
@@ -0,0 +1,106 @@
+// license:BSD-3-Clause
+// copyright-holders:Curt Coder
+/*********************************************************************
+
+ formats/sc3000_bit.c
+
+ Cassette code for Sega SC-3000 *.bit files
+
+*********************************************************************/
+
+#include <assert.h>
+
+#include "sc3000_bit.h"
+
+/***************************************************************************
+ PARAMETERS
+***************************************************************************/
+
+#define LOG 0
+
+/***************************************************************************
+ IMPLEMENTATION
+***************************************************************************/
+
+/*-------------------------------------------------
+ CassetteModulation sc3000_bit_modulation
+-------------------------------------------------*/
+
+static const struct CassetteModulation sc3000_bit_modulation =
+{
+ CASSETTE_MODULATION_SINEWAVE,
+ 1200.0 - 300, 1200.0, 1200.0 + 300,
+ 2400.0 - 600, 2400.0, 2400.0 + 600
+};
+
+/*-------------------------------------------------
+ sc3000_bit_identify - identify cassette
+-------------------------------------------------*/
+
+static casserr_t sc3000_bit_identify(cassette_image *cassette, struct CassetteOptions *opts)
+{
+ return cassette_modulation_identify( cassette, &sc3000_bit_modulation, opts);
+}
+
+/*-------------------------------------------------
+ sc3000_bit_load - load cassette
+-------------------------------------------------*/
+
+#define MODULATE(_value) \
+ for (int i = 0; i < (_value ? 2 : 1); i++) { \
+ err = cassette_put_modulated_data_bit(cassette, 0, time_index, _value, &sc3000_bit_modulation, &time_displacement);\
+ if (err) return err;\
+ time_index += time_displacement;\
+ }
+
+static casserr_t sc3000_bit_load(cassette_image *cassette)
+{
+ casserr_t err;
+ UINT64 image_size = cassette_image_size(cassette);
+ UINT64 image_pos = 0;
+ double time_index = 0.0;
+ double time_displacement;
+ UINT8 data;
+
+ while (image_pos < image_size)
+ {
+ cassette_image_read(cassette, &data, image_pos, 1);
+
+ switch (data)
+ {
+ case '1':
+ MODULATE(1);
+ break;
+
+ case '0':
+ MODULATE(0);
+ break;
+
+ case ' ':
+ err = cassette_put_sample( cassette, 0, time_index, 1/1200.0, 0);
+ if (err) return err;
+ time_index += 1/1200.0;
+ break;
+ }
+
+ image_pos++;
+ }
+
+ return CASSETTE_ERROR_SUCCESS;
+}
+
+/*-------------------------------------------------
+ CassetteFormat sc3000_bit_cassette_format
+-------------------------------------------------*/
+
+const struct CassetteFormat sc3000_bit_format =
+{
+ "bit",
+ sc3000_bit_identify,
+ sc3000_bit_load,
+ NULL
+};
+
+CASSETTE_FORMATLIST_START( sc3000_cassette_formats )
+ CASSETTE_FORMAT(sc3000_bit_format)
+CASSETTE_FORMATLIST_END