xref: /original-bsd/sys/i386/isa/fdreg.h (revision bacd16ee)
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  *
7  *	@(#)fdreg.h	8.1 (Berkeley) 06/11/93
8  */
9 
10 /*
11  * AT floppy controller registers and bitfields
12  */
13 
14 /* uses NEC765 controller */
15 #include <i386/isa/ic/nec765.h>
16 
17 /* registers */
18 #define	fdout	2	/* Digital Output Register (W) */
19 #define	FDO_FDSEL	0x01	/*  floppy device select */
20 #define	FDO_FRST	0x04	/*  floppy controller reset */
21 #define	FDO_FDMAEN	0x08	/*  enable floppy DMA and Interrupt */
22 #define	FDO_MOEN0	0x10	/*  motor enable drive 0 */
23 #define	FDO_MOEN1	0x20	/*  motor enable drive 1 */
24 
25 #define	fdsts	4	/* NEC 765 Main Status Register (R) */
26 #define	fddata	5	/* NEC 765 Data Register (R/W) */
27 
28 #define	fdctl	7	/* Control Register (W) */
29 #define	FDC_500KBPS	0x00	/* 500KBPS MFM drive transfer rate */
30 #define	FDC_300KBPS	0x01	/* 300KBPS MFM drive transfer rate */
31 #define	FDC_250KBPS	0x02	/* 250KBPS MFM drive transfer rate */
32 #define	FDC_125KBPS	0x03	/* 125KBPS FM drive transfer rate */
33 
34 #define	fdin	7	/* Digital Input Register (R) */
35 #define	FDI_DCHG	0x80	/* diskette has been changed */
36 
37 
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