(MESS) pc98: added support for disks in .fdd format. [Fabio Priuli]

src/lib/formats/pc98fdd_dsk.c

@@ -0,0 +1,149 @@
+// license:BSD-3-Clause
+// copyright-holders:etabeta
+/*********************************************************************
+
+    formats/pc98fdd_dsk.h
+
+    PC98FDD disk images
+ 
+    0xC3FC header, followed by track data
+    Sector map starts at offset 0xDC, with 12bytes for each sector
+
+    Each entry of the sector map has the following structure
+    - 0x0 = track number (if 0xff the sector/track is unformatted/unused)
+    - 0x1 = head number
+    - 0x2 = sector number
+    - 0x3 = sector size (128 << this byte)
+    - 0x4 = fill byte. if it's not 0xff, then this sector in the original
+            disk consisted of this single value repeated for the whole 
+            sector size, and the sector is skipped in the .fdd file. 
+            if it's 0xff, then this sector is wholly contained in the .fdd 
+            file
+    - 0x5 = ??
+    - 0x6 = ??
+    - 0x7 = ??
+    - 0x8-0x0b = absolute offset of the data for this sector, or 0xfffffff
+                 if the sector was skipped in the .fdd (and it has to be 
+                 filled with the value at 0x4)
+
+ TODO:
+    - Investigate remaining sector map bytes (maybe related to protections?)
+
+*********************************************************************/
+
+#include "emu.h"
+#include "pc98fdd_dsk.h"
+
+pc98fdd_format::pc98fdd_format()
+{
+}
+
+const char *pc98fdd_format::name() const
+{
+	return "pc98_fdd";
+}
+
+const char *pc98fdd_format::description() const
+{
+	return "PC98 FDD disk image";
+}
+
+const char *pc98fdd_format::extensions() const
+{
+	return "fdd";
+}
+
+int pc98fdd_format::identify(io_generic *io, UINT32 form_factor)
+{
+	UINT8 h[7];	
+	io_generic_read(io, h, 0, 7);
+	
+	if (strncmp((const char *)h, "VFD1.0", 6) == 0)
+		return 100;
+	
+	return 0;
+}
+
+bool pc98fdd_format::load(io_generic *io, UINT32 form_factor, floppy_image *image)
+{
+	UINT8 hsec[0x0c];	
+	
+	// sector map
+	UINT8 num_secs[160];
+	UINT32 track_sizes[160];
+	UINT8 tracks[160 * 26];
+	UINT8 heads[160 * 26];
+	UINT8 secs[160 * 26];
+	UINT8 fill_vals[160 * 26];
+	UINT32 sec_offs[160 * 26];
+	UINT8 sec_sizes[160 * 26];
+	
+	int pos = 0xdc;
+	
+	for (int track = 0; track < 160; track++)
+	{
+		int curr_num_sec = 0, curr_track_size = 0;
+		for (int sect = 0; sect < 26; sect++)
+		{
+			// read sector map for this sector
+			io_generic_read(io, hsec, pos, 0x0c);
+			pos += 0x0c;
+			
+			if (hsec[0] == 0xff)	// unformatted/unused sector
+				continue;
+			
+			tracks[(track * 26) + sect] = hsec[0];
+			heads[(track * 26) + sect] = hsec[1];
+			secs[(track * 26) + sect] = hsec[2];
+			sec_sizes[(track * 26) + sect] = hsec[3];
+			fill_vals[(track * 26) + sect] = hsec[4];
+			sec_offs[(track * 26) + sect] = LITTLE_ENDIANIZE_INT32(*(UINT32 *)(hsec + 0x08));
+
+			curr_track_size += (128 << hsec[3]);
+			curr_num_sec++;
+		}
+		num_secs[track] = curr_num_sec;
+		track_sizes[track] = curr_track_size;
+	}
+
+	int cell_count = form_factor == floppy_image::FF_35 ? 200000 : 166666;
+	desc_pc_sector sects[256];
+	UINT8 sect_data[65536];
+	int cur_sec_map = 0, sector_size;
+
+	for (int track = 0; track < 160; track++)
+	{		
+		int cur_pos = 0;
+		for (int i = 0; i < num_secs[track]; i++) 
+		{
+			cur_sec_map = track * 26 + i;
+			sector_size = 128 << sec_sizes[cur_sec_map];
+
+			if (sec_offs[cur_sec_map] == 0xffffffff)
+				memset(sect_data + cur_pos, fill_vals[cur_sec_map], sector_size);
+			else
+				io_generic_read(io, sect_data + cur_pos, sec_offs[cur_sec_map], sector_size);
+			
+			sects[i].track       = tracks[cur_sec_map];
+			sects[i].head        = heads[cur_sec_map];
+			sects[i].sector      = secs[cur_sec_map];
+			sects[i].size        = sec_sizes[cur_sec_map];
+			sects[i].actual_size = sector_size;
+			sects[i].deleted     = false;
+			sects[i].bad_crc     = false;
+			sects[i].data        = sect_data + cur_pos;
+			cur_pos += sector_size;
+		}
+
+		build_pc_track_mfm(track / 2, track % 2, image, cell_count, num_secs[track], sects, calc_default_pc_gap3_size(form_factor, (128 << sec_sizes[track * 26])));
+	}
+	
+	return true;
+}
+
+bool pc98fdd_format::supports_save() const
+{
+	return false;
+}
+
+const floppy_format_type FLOPPY_PC98FDD_FORMAT = &floppy_image_format_creator<pc98fdd_format>;

src/lib/formats/pc98fdd_dsk.h

@@ -0,0 +1,31 @@
+/*********************************************************************
+
+    formats/pc98fdd_dsk.h
+
+    PC98FDD disk images
+
+*********************************************************************/
+
+#ifndef PC98FDD_DSK_H
+#define PC98FDD_DSK_H
+
+#include "flopimg.h"
+
+
+class pc98fdd_format : public floppy_image_format_t
+{
+public:
+	pc98fdd_format();
+
+	virtual int identify(io_generic *io, UINT32 form_factor);
+	virtual bool load(io_generic *io, UINT32 form_factor, floppy_image *image);
+
+	virtual const char *name() const;
+	virtual const char *description() const;
+	virtual const char *extensions() const;
+	virtual bool supports_save() const;
+};
+
+extern const floppy_format_type FLOPPY_PC98FDD_FORMAT;
+
+#endif /* PC98FDD_DSK_H */

src/lib/lib.mak

@@ -183,6 +183,7 @@ FORMATSOBJS = \
 	$(LIBOBJ)/formats/pc_dsk.o      \
 	$(LIBOBJ)/formats/pc98_dsk.o    \
 	$(LIBOBJ)/formats/pc98fdi_dsk.o \
+	$(LIBOBJ)/formats/pc98fdd_dsk.o \
 	$(LIBOBJ)/formats/pc98dcp_dsk.o \
 	$(LIBOBJ)/formats/pc98dip_dsk.o \
 	$(LIBOBJ)/formats/pc98nfd_dsk.o \

src/mess/drivers/pc9801.c

@@ -416,6 +416,7 @@ Keyboard TX commands:
 
 #include "formats/pc98_dsk.h"
 #include "formats/pc98fdi_dsk.h"
+#include "formats/pc98fdd_dsk.h"
 #include "formats/pc98dcp_dsk.h"
 #include "formats/pc98dip_dsk.h"
 #include "formats/pc98nfd_dsk.h"
@@ -3099,6 +3100,7 @@ INTERRUPT_GEN_MEMBER(pc9801_state::pc9801_vrtc_irq)
 FLOPPY_FORMATS_MEMBER( pc9801_state::floppy_formats )
 	FLOPPY_PC98_FORMAT,
 	FLOPPY_PC98FDI_FORMAT,
+	FLOPPY_PC98FDD_FORMAT,
 	FLOPPY_PC98DCP_FORMAT,
 	FLOPPY_PC98DIP_FORMAT,
 	FLOPPY_PC98NFD_FORMAT