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CONTRIBUTIONS/z80em86/bios/dphunit.lib

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+;**************************************************************************
+;*               CP/M 3 BIOS for Z80em86 Z80 CPU emulator                 *
+;*                                                                        *
+;*                  DPH unit byte definition for CP/M 3                   *
+;*                                                                        *
+;*                  Copyright (C) 1992-2009 Stewart Kay                   *
+;**************************************************************************
+;
+; ChangeLog (most recent entries are at top)
+; ------------------------------------------
+; v1.0.0 - 16 February 2009, S.J.Kay
+; - Prepare for public release.
+;
+; v1.00 - 17 April 1995, S.J.Kay
+; - Undocumented changes.
+;
+; v0.00 - 1992, S.J.Kay
+; - Initial creation date.
+
+; DPH UNIT (@RDRV) byte mode bits
+
+; bit 7, 6 - cylinder format
+uddsk	equ	00000000b	;double sided up-down disk
+dsdsk	equ	01000000b	;double sided disk
+ssdsk	equ	10000000b	;single sided disk
+
+; bit 5, 4 - disk density
+sden	equ	00000000b	;single density
+dden	equ	00010000b	;double density
+hden	equ	00100000b	;high density
+
+; bit 3, 2 - drive type
+flp	equ	00000000b	;floppy type
+hdd	equ	00000100b	;HDD drive type
+ram	equ	00001000b	;RAM drive type
+
+; bit 1, 0 - drive select
+drv0	equ	00000000b	;drive select code 0
+drv1	equ	00000001b	;drive select code 1
+drv2	equ	00000010b	;drive select code 2
+drv3	equ	00000011b	;drive select code 3
+
+; end of file