;**************************************************************************
;*               CP/M 3 BIOS for Z80em86 Z80 CPU emulator                 *
;*                                                                        *
;*                           Hard disk driver                             *
;*                                                                        *
;*                  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.

; Entry point 1  : ihdsk - Initialize
; Entry point 2  : lhdsk - Login
; Entry point 3  : whdsk - Write sector
; Entry point 4  : rhdsk - Read sector

	.z80
;
	maclib	TPORTS.LIB
	maclib	ASMTYPE.LIB
;
	public	ihdsk, lhdsk, rhdsk, whdsk
;
	extrn	@dtbl, @adrv, @rdrv, @dbnk, @dma, @trk, @sect, @cnt
	extrn	HDDdsk, dph2
;
	dseg			;banked memory

; Entry point 1 - Initialize hard disk
ihdsk:	ld	hl,0
	ld	(HDDdsk),hl	;kill the HDD file entry (was for GENCPM)
	out	(gthard),a	;get the HDD file drive code
	cp	16		;is drive code in range ?
	ret	nc
	inc	a		;HDD file present ?
	ret	z
	dec	a		;restore drive code number
	add	a,a
	ld	d,0
	ld	e,a
	ld	hl,@dtbl	;drive table address
	add	hl,de		;table offset for DPH entry
	ld	de,dph2		;DPH address for HDD file
	ld	(hl),e
	inc	hl
	ld	(hl),d
	ret

; Entry point 2 - Login hard disk drive
lhdsk:	ret

; Entry point 3 - Write hard disk sector
whdsk:	or	0ffh		;write operation flag value
	jp	hdisk

; Entry point 4 - Read hard disk sector
rhdsk:	xor	a		;read operation flag value

hdisk:	push	af		;save operation flag
if banked
	ld	a,(@dbnk)
	out	(bnkdma),a
endif
	ld	a,(@trk)
	ld	b,a
	ld	a,(@sect)
	ld	c,a
	ld	a,(@adrv)
	ld	e,a
	ld	hl,(@dma)
	pop	af		;restore operation flag
	ld	a,2		;sector size code (512 bytes)
	jp	z,readop
	out	(wrhard),a
	jp	result
readop:	out	(rdhard),a
result:	or	a
	ret	z
	ld	a,1
	ret
;
	end