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r7277 Saturday 6th February, 2010 at 16:05:45 UTC by Curt Coder
[D81] Fixed sector offset calculation.

[src/mess/formats]

d81_dsk.c

src/mess/formats/d81_dsk.c

r7276	r7277
13	13	PARAMETERS
14	14	***************************************************************************/
15	15
16		#define LOG 0
17
18	16	#define D81_SIZE   819200
19	17
20	18	/***************************************************************************
r7276	r7277
71	69
72	70	UINT64 d81_translate_offset(floppy_image *floppy, const struct basicdsk_geometry *geom, int track, int head, int sector)
73	71	{
74		UINT64 offset = ((track * 20) + (!head * 10) + (sector - 1)) * 512;
	72	UINT64 offset = (track * 20) + (!head * 10) + sector;
75	73
76		if (LOG) logerror("D81 offset %06x: track %u head %u sector %u\n", (UINT32)offset, track, head, sector);
77
78	74	return offset;
79	75	}
80	76
r7276	r7277
93	89	FLOPPY_CONSTRUCT( d81_dsk_construct )
94	90	-------------------------------------------------*/
95	91
	92	/*
	93	PER TRACK ORGANIZATION:
	94
	95	Hex 4E written as a gap, with 10 sectors of data, with full gaps written for motor speed variation.
	96
	97	PER SECTOR ORGANIZATION:
	98
	99	MFM Encoding
	100	12 Bytes of Hex 00
	101	3 Bytes of Hex A1 (Data Hex A1, Clock Hex 0A)
	102	1 Byte of Hex FE (ID Address Mark)
	103	1 Byte (Track Number)
	104	1 Byte (Side Number)
	105	1 Byte (Sector Number)
	106	1 Byte (Sector Length, 02 for 512 Byte Sectors)
	107	2 Bytes CRC (Cyclic Redundancy Check)
	108	22 Bytes of Hex 22
	109	12 Bytes of Hex 00
	110	3 Bytes of Hex A1 (Data Hex A1, Clock Hex 0A)
	111	1 Byte of Hex FB (Data Address Mark)
	112	512 Bytes of Data
	113	2 Bytes of CRC (Cyclic Redundancy Check)
	114	38 Bytes of Hex 4E
	115	*/
	116
96	117	FLOPPY_CONSTRUCT( d81_dsk_construct )
97	118	{
98	119	struct basicdsk_geometry geometry;

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