floppy: Handle half and quarter tracks [O. Galibert]

src/emu/imagedev/floppy.c

@@ -273,6 +273,7 @@ void floppy_image_device::device_start()
 	mon = 1;
 
 	cyl = 0;
+	subcyl = 0;
 	ss  = 0;
 	stp = 1;
 	wpt = 0;
@@ -535,9 +536,51 @@ void floppy_image_device::stp_w(int state)
 				if (dskchg==0) dskchg = 1;
 			}
 		}
+		subcyl = 0;
 	}
 }
 
+void floppy_image_device::seek_phase_w(int phases)
+{
+	int cur_pos = (cyl << 2) | subcyl;
+	int req_pos;
+	switch(phases) {
+	case 0x1: req_pos = 0; break;
+	case 0x3: req_pos = 1; break;
+	case 0x2: req_pos = 2; break;
+	case 0x6: req_pos = 3; break;
+	case 0x4: req_pos = 4; break;
+	case 0xc: req_pos = 5; break;
+	case 0x8: req_pos = 6; break;
+	case 0x9: req_pos = 7; break;
+	default: return;
+	}
+
+	// Opposite phase, don't move
+	if(((cur_pos ^ req_pos) & 7) == 4)
+		return;
+
+	int next_pos = (cur_pos & ~7) | req_pos;
+	if(next_pos < cur_pos-4)
+		next_pos += 8;
+	else if(next_pos > cur_pos+4)
+		next_pos -= 8;
+	if(next_pos < 0)
+		next_pos = 0;
+	else if(next_pos > (tracks-1)*4)
+		next_pos = (tracks-1)*4;
+	cyl = next_pos >> 2;
+	subcyl = next_pos & 3;
+
+	if(TRACE_STEP && (next_pos != cur_pos))
+		logerror("%s: track %d.%d\n", tag(), cyl, subcyl);
+
+	/* Update disk detection if applicable */
+	if (exists())
+		if (dskchg==0)
+			dskchg = 1;
+}
+
 int floppy_image_device::find_index(UINT32 position, const UINT32 *buf, int buf_size)
 {
 	int spos = (buf_size >> 1)-1;

src/emu/imagedev/floppy.h

@@ -105,6 +105,7 @@ public:
 	bool ss_r() { return ss; }
 	bool twosid_r();
 
+	void seek_phase_w(int phases);
 	void stp_w(int state);
 	void dir_w(int state) { dir = state; }
 	void ss_w(int state) { ss = state; }
@@ -164,7 +165,7 @@ protected:
 
 	attotime revolution_start_time, rev_time;
 	UINT32 revolution_count;
-	int cyl;
+	int cyl, subcyl;
 
 	bool image_dirty;
 	int ready_counter;

src/emu/machine/wozfdc.c

@@ -72,7 +72,6 @@ void wozfdc_device::device_start()
 
 void wozfdc_device::device_reset()
 {
-	current_cyl = 0;
 	floppy = NULL;
 	active = MODE_IDLE;
 	phases = 0x00;
@@ -199,22 +198,8 @@ void wozfdc_device::phase(int ph, bool on)
 	else
 		phases &= ~(1 << ph);
 
-	if(floppy && active) {
+	if(floppy && active)
-		int cph = current_cyl & 3;
+		floppy->seek_phase_w(phases);
-		int pcyl = current_cyl;
-		if(!(phases & (1 << cph))) {
-			if(current_cyl < 70 && (phases & (1 << ((cph+1) & 3))))
-				current_cyl++;
-			if(current_cyl && (phases & (1 << ((cph+3) & 3))))
-				current_cyl--;
-			if(current_cyl != pcyl && !(current_cyl & 1)) {
-				floppy->dir_w(current_cyl < pcyl);
-				floppy->stp_w(true);
-				floppy->stp_w(false);
-				floppy->stp_w(true);
-			}
-		}
-	}
 }
 
 void wozfdc_device::control(int offset)
@@ -238,10 +223,8 @@ void wozfdc_device::control(int offset)
 		case 0x9:
 			switch(active) {
 			case MODE_IDLE:
-				if(floppy) {
+				if(floppy)
 					floppy->mon_w(false);
-					current_cyl = floppy->get_cyl() << 1;
-				}
 				active = MODE_ACTIVE;
 				if(floppy)
 					lss_start();

src/emu/machine/wozfdc.h

@@ -60,7 +60,7 @@ private:
 	};
 
 	const UINT8 *m_rom_p6;
-	UINT8 current_cyl, last_6502_write;
+	UINT8 last_6502_write;
 	bool mode_write, mode_load;
 	int active;
 	UINT8 phases;

src/lib/formats/flopimg.c

@@ -947,19 +947,13 @@ floppy_image::floppy_image(int _tracks, int _heads, UINT32 _form_factor)
 	form_factor = _form_factor;
 	variant = 0;
 
-	memset(cell_data, 0, sizeof(cell_data));
+	track_array.resize(tracks*4+1);
-	memset(track_size, 0, sizeof(track_size));
+	for(int i=0; i<tracks*4+1; i++)
-	memset(track_alloc_size, 0, sizeof(track_alloc_size));
+		track_array[i].resize(heads);
-	memset(write_splice, 0, sizeof(write_splice));
 }
 
 floppy_image::~floppy_image()
 {
-	for (int i=0;i<MAX_FLOPPY_TRACKS;i++) {
-		for (int j=0;j<MAX_FLOPPY_HEADS;j++) {
-			global_free_array(cell_data[i][j]);
-		}
-	}
 }
 
 void floppy_image::get_maximal_geometry(int &_tracks, int &_heads)
@@ -970,7 +964,7 @@ void floppy_image::get_maximal_geometry(int &_tracks, int &_heads)
 
 void floppy_image::get_actual_geometry(int &_tracks, int &_heads)
 {
-	int maxt = tracks-1, maxh = heads-1;
+	int maxt = tracks*4, maxh = heads-1;
 
 	while(maxt >= 0) {
 		for(int i=0; i<=maxh; i++)
@@ -987,22 +981,29 @@ void floppy_image::get_actual_geometry(int &_tracks, int &_heads)
 			maxh--;
 		}
 	head_done:
-	_tracks = maxt+1;
+	_tracks = (maxt+4)/4;
 	_heads = maxh+1;
 }
 
+int floppy_image::get_resolution() const
+{
+	int mask = 0;
+	for(int i=0; i<tracks*4+1; i++)
+		for(int j=0; j<heads; j++)
+			if(track_array[i][j].track_size)
+				mask |= 1 << (i & 3);
+	if(mask & 0xa)
+		return 2;
+	if(mask & 0x4)
+		return 1;
+	return 0;
+}
+
 void floppy_image::ensure_alloc(int track, int head)
 {
-	if(track_size[track][head] > track_alloc_size[track][head]) {
+	track_info &tr = track_array[track][head];
-		UINT32 new_size = track_size[track][head]*11/10;
+	if(tr.track_size > tr.cell_data.count())
-		UINT32 *new_array = global_alloc_array(UINT32, new_size);
+		tr.cell_data.resize_keep_and_clear_new(tr.track_size);
-		if(track_alloc_size[track][head]) {
-			memcpy(new_array, cell_data[track][head], track_alloc_size[track][head]*4);
-			global_free_array(cell_data[track][head]);
-		}
-		cell_data[track][head] = new_array;
-		track_alloc_size[track][head] = new_size;
-	}
 }
 
 const char *floppy_image::get_variant_name(UINT32 form_factor, UINT32 variant)

src/lib/formats/flopimg.h

@@ -12,6 +12,7 @@
 #include "osdcore.h"
 #include "ioprocs.h"
 #include "opresolv.h"
+#include "coretmpl.h"
 
 #ifndef LOG_FORMATS
 #define LOG_FORMATS if (0) printf
@@ -637,7 +638,13 @@ floppy_image_format_t *floppy_image_format_creator()
 //! form factor can be physically inserted in a reader that handles
 //! it.  The second half indicates the variants which are usually
 //! detectable by the reader, such as density and number of sides.
-
+//!
+//! Resolution is quarter-track.  The optional subtrack parameter is
+//! 0-3:
+//! - 0 = Track itself
+//! - 1 = 1st quarter track
+//! - 2 = Half track
+//! - 3 = 2nd quarter track
 
 class floppy_image
 {
@@ -682,7 +689,7 @@ public:
 		M2FM = 0x4D32464D, //!< "M2FM", modified modified frequency modulation
 	};
 
-// construction/destruction
+	// construction/destruction
 
 
 	//! floppy_image constructor
@@ -703,21 +710,25 @@ public:
 
 	/*!
 	  @param track
+	  @param subtrack
 	  @param head
 	  @param size size of this track
 	*/
-	void set_track_size(int track, int head, UINT32 size) { track_size[track][head] = size; ensure_alloc(track, head); }
+	void set_track_size(int track, int head, UINT32 size, int subtrack = 0) { track_array[track*4+subtrack][head].track_size = size; ensure_alloc(track*4+subtrack, head); }
 
 	/*!
-	  @param track track number
+	  @param track
+	  @param subtrack
 	  @param head head number
 	  @return a pointer to the data buffer for this track and head
 	*/
-	UINT32 *get_buffer(int track, int head) { return cell_data[track][head]; }
+	UINT32 *get_buffer(int track, int head, int subtrack = 0) { return track_array[track*4+subtrack][head].cell_data; }
+
 	//! @return the track size
 	//! @param track
+	//! @param subtrack
 	//! @param head
-	UINT32 get_track_size(int track, int head) { return track_size[track][head]; }
+	UINT32 get_track_size(int track, int head, int subtrack = 0) { return track_array[track*4+subtrack][head].track_size; }
 
 	//! Sets the write splice position.
 	//! The "track splice" information indicates where to start writing
@@ -727,18 +738,22 @@ public:
 	//! representation is the angular position relative to the index.
 
 	/*! @param track
+	    @param subtrack
 	    @param head
 	    @param pos the position
 	*/
-	void set_write_splice_position(int track, int head, UINT32 pos) { write_splice[track][head] = pos; }
+	void set_write_splice_position(int track, int head, UINT32 pos, int subtrack = 0) { track_array[track*4+subtrack][head].write_splice = pos; }
 	//! @return the current write splice position.
-	UINT32 get_write_splice_position(int track, int head) const { return write_splice[track][head]; }
+	UINT32 get_write_splice_position(int track, int head, int subtrack = 0) const { return track_array[track*4+subtrack][head].write_splice; }
 	//! @return the maximal geometry supported by this format.
 	void get_maximal_geometry(int &tracks, int &heads);
 
 	//! @return the current geometry of the loaded image.
 	void get_actual_geometry(int &tracks, int &heads);
 
+	//! @return the track resolution (0=full track, 1 = half-track, 2 = quarter track)
+	int get_resolution() const;
+
 	//! Returns the variant name for the particular disk form factor/variant
 	//! @param form_factor
 	//! @param variant
@@ -746,20 +761,21 @@ public:
 	static const char *get_variant_name(UINT32 form_factor, UINT32 variant);
 
 private:
-
-	enum {
-		MAX_FLOPPY_HEADS = 2,
-		MAX_FLOPPY_TRACKS = 84
-	};
-
 	int tracks, heads;
 
 	UINT32 form_factor, variant;
 
-	UINT32 *cell_data[MAX_FLOPPY_TRACKS][MAX_FLOPPY_HEADS];
+	struct track_info {
-	UINT32 track_size[MAX_FLOPPY_TRACKS][MAX_FLOPPY_HEADS];
+		dynamic_array<UINT32> cell_data;
-	UINT32 track_alloc_size[MAX_FLOPPY_TRACKS][MAX_FLOPPY_HEADS];
+		UINT32 track_size;
-	UINT32 write_splice[MAX_FLOPPY_TRACKS][MAX_FLOPPY_HEADS];
+		UINT32 write_splice;
+
+		track_info() { track_size = write_splice = 0; }
+	};
+
+	// track number multiplied by 4 then head
+	// last array size may be bigger than actual track size
+	dynamic_array<dynamic_array<track_info> > track_array;
 
 	void ensure_alloc(int track, int head);
 };

src/lib/formats/mfi_dsk.c

@@ -8,10 +8,12 @@
   Mess floppy image structure:
 
   - header with signature, number of cylinders, number of heads.  Min
-    track and min head are considered to always be 0.
+    track and min head are considered to always be 0.  The two top bits
+    of the cylinder count is the resolution: 0=tracks, 1=half tracks,
+    2=quarter tracks.
 
-  - vector of track descriptions, looping on cylinders and sub-lopping
+  - vector of track descriptions, looping on cylinders with the given
-    on heads, each description composed of:
+    resolution and sub-lopping on heads, each description composed of:
     - offset of the track data in bytes from the start of the file
     - size of the compressed track data in bytes (0 for unformatted)
     - size of the uncompressed track data in bytes (0 for unformatted)
@@ -97,7 +99,8 @@ int mfi_format::identify(io_generic *io, UINT32 form_factor)
 
 	io_generic_read(io, &h, 0, sizeof(header));
 	if(memcmp( h.sign, sign, 16 ) == 0 &&
-		h.cyl_count <= 160 &&
+	   (h.cyl_count & CYLINDER_MASK) <= 84 &&
+	   (h.cyl_count >> RESOLUTION_SHIFT) < 3 &&
 		h.head_count <= 2 &&
 		(!form_factor || !h.form_factor || h.form_factor == form_factor))
 		return 100;
@@ -107,22 +110,24 @@ int mfi_format::identify(io_generic *io, UINT32 form_factor)
 bool mfi_format::load(io_generic *io, UINT32 form_factor, floppy_image *image)
 {
 	header h;
-	entry entries[84*2];
+	entry entries[84*2*4];
 	io_generic_read(io, &h, 0, sizeof(header));
-	io_generic_read(io, &entries, sizeof(header), h.cyl_count*h.head_count*sizeof(entry));
+	int resolution = h.cyl_count >> RESOLUTION_SHIFT;
+	h.cyl_count &= CYLINDER_MASK;
+	io_generic_read(io, &entries, sizeof(header), (h.cyl_count << resolution)*h.head_count*sizeof(entry));
 
 	image->set_variant(h.variant);
 
 	dynamic_buffer compressed;
 
 	entry *ent = entries;
-	for(unsigned int cyl=0; cyl != h.cyl_count; cyl++)
+	for(unsigned int cyl=0; cyl <= (h.cyl_count - 1) << 2; cyl += 4 >> resolution)
 		for(unsigned int head=0; head != h.head_count; head++) {
-			image->set_write_splice_position(cyl, head, ent->write_splice);
+			image->set_write_splice_position(cyl >> 2, head, ent->write_splice, cyl & 3);
 
 			if(ent->uncompressed_size == 0) {
 				// Unformatted track
-				image->set_track_size(cyl, head, 0);
+				image->set_track_size(cyl >> 2, head, 0, cyl & 3);
 				ent++;
 				continue;
 			}
@@ -132,8 +137,8 @@ bool mfi_format::load(io_generic *io, UINT32 form_factor, floppy_image *image)
 			io_generic_read(io, compressed, ent->offset, ent->compressed_size);
 
 			unsigned int cell_count = ent->uncompressed_size/4;
-			image->set_track_size(cyl, head, cell_count);
+			image->set_track_size(cyl >> 2, head, cell_count, cyl & 3);
-			UINT32 *trackbuf = image->get_buffer(cyl, head);
+			UINT32 *trackbuf = image->get_buffer(cyl >> 2, head, cyl & 3);
 
 			uLongf size = ent->uncompressed_size;
 			if(uncompress((Bytef *)trackbuf, &size, compressed, ent->compressed_size) != Z_OK)
@@ -158,18 +163,19 @@ bool mfi_format::save(io_generic *io, floppy_image *image)
 {
 	int tracks, heads;
 	image->get_actual_geometry(tracks, heads);
+	int resolution = image->get_resolution();
 	int max_track_size = 0;
-	for(int track=0; track<tracks; track++)
+	for(int track=0; track <= (tracks-1) << 2; track += 4 >> resolution)
 		for(int head=0; head<heads; head++) {
-			int tsize = image->get_track_size(track, head);
+			int tsize = image->get_track_size(track >> 2, head, track & 3);
 			if(tsize > max_track_size)
 					max_track_size = tsize;
 		}
 
 	header h;
-	entry entries[84*2];
+	entry entries[84*2*4];
 	memcpy(h.sign, sign, 16);
-	h.cyl_count = tracks;
+	h.cyl_count = tracks | (resolution << RESOLUTION_SHIFT);
 	h.head_count = heads;
 	h.form_factor = image->get_form_factor();
 	h.variant = image->get_variant();
@@ -178,20 +184,20 @@ bool mfi_format::save(io_generic *io, floppy_image *image)
 
 	memset(entries, 0, sizeof(entries));
 
-	int pos = sizeof(header) + tracks*heads*sizeof(entry);
+	int pos = sizeof(header) + (tracks << resolution)*heads*sizeof(entry);
 	int epos = 0;
 	UINT32 *precomp = global_alloc_array(UINT32, max_track_size);
 	UINT8 *postcomp = global_alloc_array(UINT8, max_track_size*4 + 1000);
 
-	for(int track=0; track<tracks; track++)
+	for(int track=0; track <= (tracks-1) << 2; track += 4 >> resolution)
 		for(int head=0; head<heads; head++) {
-			int tsize = image->get_track_size(track, head);
+			int tsize = image->get_track_size(track >> 2, head, track & 3);
 			if(!tsize) {
 				epos++;
 				continue;
 			}
 
-			memcpy(precomp, image->get_buffer(track, head), tsize*4);
+			memcpy(precomp, image->get_buffer(track >> 2, head, track & 3), tsize*4);
 			for(int j=0; j<tsize-1; j++)
 				precomp[j] = (precomp[j] & floppy_image::MG_MASK) |
 					((precomp[j+1] & floppy_image::TIME_MASK) -
@@ -206,14 +212,14 @@ bool mfi_format::save(io_generic *io, floppy_image *image)
 			entries[epos].offset = pos;
 			entries[epos].uncompressed_size = tsize*4;
 			entries[epos].compressed_size = csize;
-			entries[epos].write_splice = image->get_write_splice_position(track, head);
+			entries[epos].write_splice = image->get_write_splice_position(track >> 2, head, track & 3);
 			epos++;
 
 			io_generic_write(io, postcomp, pos, csize);
 			pos += csize;
 		}
 
-	io_generic_write(io, entries, sizeof(header), tracks*heads*sizeof(entry));
+	io_generic_write(io, entries, sizeof(header), (tracks << resolution)*heads*sizeof(entry));
 	return true;
 }
 

src/lib/formats/mfi_dsk.h

@@ -26,7 +26,10 @@ private:
 		MG_A      = (0 << MG_SHIFT),
 		MG_B      = (1 << MG_SHIFT),
 		MG_N      = (2 << MG_SHIFT),
-		MG_D      = (3 << MG_SHIFT)
+		MG_D      = (3 << MG_SHIFT),
+
+		RESOLUTION_SHIFT = 30,
+		CYLINDER_MASK = 0x3fffffff
 	};
 
 	static const char sign[16];