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-rw-r--r--src/lib/formats/dfi_dsk.cpp227
1 files changed, 227 insertions, 0 deletions
diff --git a/src/lib/formats/dfi_dsk.cpp b/src/lib/formats/dfi_dsk.cpp
new file mode 100644
index 00000000000..ce89e02f31a
--- /dev/null
+++ b/src/lib/formats/dfi_dsk.cpp
@@ -0,0 +1,227 @@
+// license:BSD-3-Clause
+// copyright-holders:Olivier Galibert
+
+/* DONE:
+ * Support auto-identification heuristics for determining disk image speed,
+ capture clock rate, and number of multireads per image.
+ * TODO:
+ * Scale captured data based on the guessed clock rate and samplerate to match
+ the internal 200mhz representation
+ * Handle 0xFF bytes properly
+ * Correctly note exact index timing.
+ */
+
+#include "emu.h" // fatalerror
+#include "dfi_dsk.h"
+#include <zlib.h>
+#define NUMBER_OF_MULTIREADS 3
+// threshholds for brickwall windowing
+//define DFI_MIN_CLOCKS 65
+// number_please apple2 wants 40 min
+#define DFI_MIN_CLOCKS 60
+//define MAX_CLOCKS 260
+#define DFI_MAX_CLOCKS 270
+#define MIN_THRESH (DFI_MIN_CLOCKS*(clock_rate/25000000))
+#define MAX_THRESH (DFI_MAX_CLOCKS*(clock_rate/25000000))
+// constants to help guess clockrate and rpm
+// constant is 25mhz / 6 revolutions per second (360rpm) = 4166667 +- 2.5%
+#define REV25_MIN 4062500
+#define REV25_MAX 4270833
+// define the following to show a histogram per track
+//define TRACK_HISTOGRAM 1
+#undef TRACK_HISTOGRAM
+
+dfi_format::dfi_format() : floppy_image_format_t()
+{
+}
+
+const char *dfi_format::name() const
+{
+ return "dfi";
+}
+
+const char *dfi_format::description() const
+{
+ return "DiscFerret flux dump format";
+}
+
+const char *dfi_format::extensions() const
+{
+ return "dfi";
+}
+
+bool dfi_format::supports_save() const
+{
+ return false;
+}
+
+int dfi_format::identify(io_generic *io, UINT32 form_factor)
+{
+ char sign[4];
+ io_generic_read(io, sign, 0, 4);
+ if (memcmp(sign, "DFER", 4)==0)
+ fatalerror("Old type Discferret image detected; the mess Discferret decoder will not handle this properly, bailing out!\n");
+ return memcmp(sign, "DFE2", 4) ? 0 : 100;
+}
+
+bool dfi_format::load(io_generic *io, UINT32 form_factor, floppy_image *image)
+{
+ UINT64 size = io_generic_size(io);
+ UINT64 pos = 4;
+ dynamic_buffer data;
+ int onerev_time = 0; // time for one revolution, used to guess clock and rpm for DFE2 files
+ unsigned long clock_rate = 100000000; // sample clock rate in megahertz
+ int rpm=360; // drive rpm
+ while(pos < size) {
+ UINT8 h[10];
+ io_generic_read(io, h, pos, 10);
+ UINT16 track = (h[0] << 8) | h[1];
+ UINT16 head = (h[2] << 8) | h[3];
+ // Ignore sector
+ UINT32 tsize = (h[6] << 24) | (h[7] << 16) | (h[8] << 8) | h[9];
+
+ // if the position-so-far-in-file plus 10 (for the header) plus track size
+ // is larger than the size of the file, free buffers and bail out
+ if(pos+tsize+10 > size) {
+ return false;
+ }
+
+ // reallocate the data array if it gets too small
+ data.resize(tsize);
+
+ pos += 10; // skip the header, we already read it
+ io_generic_read(io, &data[0], pos, tsize);
+ pos += tsize; // for next time we read, increment to the beginning of next header
+
+ int index_time = 0; // what point the last index happened
+ int index_count = 0; // number of index pulses per track
+ //int index_polarity = 1; // current polarity of index, starts high
+ int total_time = 0; // total sampled time per track
+ for(int i=0; i<tsize; i++) {
+ UINT8 v = data[i];
+ if (v == 0xFF) { fprintf(stderr,"DFI stream contained a 0xFF at t%d, position%d, THIS SHOULD NEVER HAPPEN! Bailing out!\n", track, i); exit(1); }
+ if((v & 0x7f) == 0x7f)
+ total_time += 0x7f;
+ else if(v & 0x80) {
+ total_time += v & 0x7f;
+ index_time = total_time;
+ //index_polarity ^= 1;
+ //fprintf(stderr,"index state changed to %d at time=%d\n", index_polarity, total_time);
+ //fprintf(stderr,"index rising edge seen at time=%d\n", total_time);
+ if (onerev_time == 0) onerev_time = total_time;
+ index_count += 1;//index_polarity;
+ } else // (v & 0x80) == 0
+ total_time += v & 0x7f;
+ }
+
+ // its possible on single read images for there to be no index pulse during the image at all!
+ if (onerev_time == 0) onerev_time = total_time;
+
+ if(!track && !head)
+ fprintf(stderr, "%02d:%d tt=%10d it=%10d\n", track, head, total_time, index_time);
+ if(!track && !head) {
+ fprintf(stderr, "index_count: %d, onerev_time: %d\n", index_count, onerev_time);
+ if ((onerev_time > REV25_MIN) && (onerev_time < REV25_MAX)) {
+ fprintf(stderr, "Guess: speed: 360rpm, clock 25MHz\n");
+ clock_rate = 25000000; rpm = 360;
+ } else if ((onerev_time > REV25_MIN*1.2) && (onerev_time < REV25_MAX*1.2)) {
+ fprintf(stderr, "Guess: speed: 300rpm, clock 25MHz\n");
+ clock_rate = 25000000; rpm = 300;
+ } else if ((onerev_time > REV25_MIN*2) && (onerev_time < REV25_MAX*2)) {
+ fprintf(stderr, "Guess: speed: 360rpm, clock 50MHz\n");
+ clock_rate = 50000000; rpm = 360;
+ } else if ((onerev_time > (REV25_MIN*2)*1.2) && (onerev_time < (REV25_MAX*2)*1.2)) {
+ fprintf(stderr, "Guess: speed: 300rpm, clock 50MHz\n");
+ clock_rate = 50000000; rpm = 300;
+ } else if ((onerev_time > REV25_MIN*4) && (onerev_time < REV25_MAX*4)) {
+ fprintf(stderr, "Guess: speed: 360rpm, clock 100MHz\n");
+ clock_rate = 100000000; rpm = 360;
+ } else if ((onerev_time > (REV25_MIN*4)*1.2) && (onerev_time < (REV25_MAX*4)*1.2)) {
+ fprintf(stderr, "Guess: speed: 300rpm, clock 100MHz\n");
+ clock_rate = 100000000; rpm = 300;
+ } else
+ fprintf(stderr, "WARNING: Cannot Guess Speed! Assuming 360rpm, 100Mhz clock!\n");
+ fprintf(stderr,"Actual rpm based on index: %f\n", ((double)clock_rate/(double)onerev_time)*60);
+ }
+
+ rpm += 0; // HACK: prevent GCC 4.6+ from warning "variable set but unused"
+
+ if(!index_time)
+ index_time = total_time;
+
+ std::vector<UINT32> &buf = image->get_buffer(track, head);
+ buf.resize(tsize);
+
+ int cur_time = 0;
+ int prev_time = 0;
+#ifdef TRACK_HISTOGRAM
+ // histogram
+ int time_buckets[4096];
+ for (int i = 0; i < 4096; i++)
+ time_buckets[i] = 0;
+#endif
+ index_count = 0;
+ //index_polarity = 0;
+ UINT32 mg = floppy_image::MG_A;
+ int tpos = 0;
+ buf[tpos++] = mg;
+ for(int i=0; i<tsize; i++) {
+ UINT8 v = data[i];
+ if((v & 0x7f) == 0x7f) // 0x7F : no transition, but a carry (FF is a board-on-fire error and is checked for above)
+ cur_time += 0x7f;
+ else if(v & 0x80) { // 0x80 set, note the index (TODO: actually do this!) and add number to count
+ cur_time += v & 0x7f;
+ //index_polarity ^= 1;
+ index_count += 1;//index_polarity;
+ //if (index_count == NUMBER_OF_MULTIREADS) break;
+ }
+ else if((v & 0x80) == 0) { // 0x00-0x7E: not an index or carry, add the number and store transition
+ cur_time += v & 0x7f;
+ int trans_time = cur_time - prev_time;
+#ifdef TRACK_HISTOGRAM
+ time_buckets[(trans_time<4096)?trans_time:4095]++;
+#endif
+ // cur_time and onerev_time need to be converted to something standard, so we'll stick with 300rpm at the standard 200mhz rate that mfi uses internally
+ // TODO for 4/22/2012: ACTUALLY DO THIS RESCALING STEP
+ // filter out spurious crap
+ //if (trans_time <= MIN_THRESH) fprintf(stderr, "DFI: Throwing out short transition of length %d\n", trans_time);
+ // the normal case: write the transition at the appropriate time
+ if ((prev_time == 0) || ((trans_time > MIN_THRESH) && (trans_time <= MAX_THRESH))) {
+ mg = mg == floppy_image::MG_A ? floppy_image::MG_B : floppy_image::MG_A;
+ buf[tpos++] = mg | UINT32((200000000ULL*cur_time)/index_time);
+ prev_time = cur_time;
+ }
+ // the long case: we probably missed a transition, stuff an extra guessed one in there to see if it helps
+ if (trans_time > MAX_THRESH) {
+ mg = mg == floppy_image::MG_A ? floppy_image::MG_B : floppy_image::MG_A;
+ if (((track%2)==0)&&(head==0)) fprintf(stderr,"missed transition, total time for transition is %d\n",trans_time);
+#ifndef FAKETRANS_ONE
+ buf[tpos++] = mg | UINT32((200000000ULL*(cur_time-(trans_time/2)))/index_time); // generate imaginary transition at half period
+#else
+ buf[tpos++] = mg | UINT32((200000000ULL*(cur_time-((trans_time*2)/3)))/index_time);
+ mg = mg == floppy_image::MG_A ? floppy_image::MG_B : floppy_image::MG_A;
+ buf[tpos++] = mg | UINT32((200000000ULL*(cur_time-(trans_time/3)))/index_time);
+#endif
+ mg = mg == floppy_image::MG_A ? floppy_image::MG_B : floppy_image::MG_A;
+ buf[tpos++] = mg | UINT32(200000000ULL*cur_time/index_time); // generate transition now
+ prev_time = cur_time;
+ }
+ }
+ }
+#ifdef TRACK_HISTOGRAM
+ if (((track%2)==0)&&(head==0)) {
+ for (int i = 0; i < 4096; i++) {
+ fprintf(stderr,"%4d:%4d ", i, time_buckets[i]);
+ if (((i+1)%10)==0) fprintf(stderr,"\n");
+ }
+ }
+ fprintf(stderr,"\n");
+#endif
+ index_count = 0;
+ buf.resize(tpos);
+ }
+
+ return true;
+}
+
+const floppy_format_type FLOPPY_DFI_FORMAT = &floppy_image_format_creator<dfi_format>;