Title	Floppy Disk Backup Program for MD-HD (23_Oct_84)
;
;	Copyright 1984
;	Morrow Designs, Inc.
;	San Leandro, Ca.
;	John Zalabak
;
	.z80
	Aseg
	org	0100h

;----------------------------------------------------------------------
; Index (23_Oct_84)
;------------------
;
;	Backup_Main	Main Proceedure of Backup
;	Save_State	Get the Entry Conditions
;	Find_Drives	Check the Drive Configuration
;	Get_Mtab_Pntr	Get a Pointer to an Mtab
;	Check_Revision	Check Versions/Revisions
;	Restore_State	Restore the Entry State
;
;	Make_a_Copy	Make a Copy of a Floppy Disk
;	Save_Disk	Save all Tracks on a Floppy Disk
;	Read_Flp_Track	Read a Track from the Floppy Disk
;	Write_Dsk_Track	Write a Track to the Save File
;
;	Restore_a_Copy	Restore a Disk from a File
;	R                                                                                                                                                                                                                                               Def	Get the Media Definition Table
;	Install_Xlt	Install the translate table for this drive
;	Enter_Xlt	Enter a new translation table into the free space
;	Install_Dph	Install the Xlt pointer in the Dph
;	Install_Dpb	OverLay the current drive's Dpb
;	Get_Pointer	Get a Pointer into the current data structure
;	Install_Mtab	Update the drive's MTAB
;
;	Erase_Character	Erase a character from the console screen
;	Pause_for_Rtn	Wait the Return Key
;	Get_Character	Get a Character from the Console
;	Put_Character	Put a Character to the Console
;	Print_Number	Print a Number in the Current Radix
;	Divide		16 bit Divide
;	Multiply	16 bit Multiply
;
;	Extended_Bios	Call the Extended Bios Entry
;	Get_Buffer	Read a Buffer (Extended Bios)
;	Put_Buffer	Write a Buffer (Extended Bios)
;	Print_Message	Print a Message on the Console
;
;	Data Areas
	page		60

;----------------------------------------------------------------------
; General Equates (23_Oct_84)
;----------------------------
;
		;Revision Numbers
Frev		equ	20h		;Format Program Revision Level
Ccl		equ	1		;Bios Compatibility Level
Rrl		equ	19h		;Rom Revision Level

		;Bios/Bdos Equates
Bios_Entry	equ	0		;Bios Entry Point
Bdos_Entry	equ	5		;Bdos:	Entry Vector Location
Bdos_PString	equ	9		;	Print a Sting on the Console
Bdos_ConBuf_In	equ	10		;	Read Console input buffer
Bdos_Ret_Ver	equ	12		;       Return CP/M version
Bdos_SelDsk	equ	14		;	Select Disk
Bdos_Open_File	equ	15		;	Open a File
Bdos_Close_File	equ	16		;	Close a File
Bdos_Search	equ	17		;	Search for File
Bdos_Delete	equ	19		;	Delete a File
Bdos_Read_Seq	equ	20		;	Read Sequential
Bdos_Write_Seq	equ	21		;	Write Sequential
Bdos_Make_File	equ	22		;	Make a File
Bdos_Crnt_Disk	equ	25		;	Return the Current Disk Number
Bdos_Set_DMA	equ	26		;	                                                                                                                                                                                                                                               _Get_Mtabs	equ	3		;Read the System Mtabs
EB_Get_Dphs	equ	4		;Get the System's Dphs
EB_Get_Dpbs	equ	5		;Read the System Dpbs
EB_Get_Char_Tbl	equ	6		;Get the Character Table
EB_Get_Free	equ	8		;Get the Free Space Pool
EB_Format	equ	9		;Format a Track
EB_Execute	equ	14		;Execute a in the System Bank
EB_Verify_D	equ	15		;Verify a Track with Re:Mapping
EB_ID_Frame	equ	18		;Read the ID Frame
EB_Read_Host	equ	20		;Read a Physical Sector
EB_Write_Host	equ	21		;Write a Physical Sector

		;Offsets
Ccl_Offset	equ	10		;Bios Compatibility from Start of Character Table
Rrl_Offset	equ	0		;Rom Revision Level from Start of ID Frame
Vnum_Offset	equ	04h		;To Numb Log Drives from Start of Char Table

ConIn_Offset	equ	9		;Bios Console Input Offset
ConOut_Offset	equ	0Ch		; "   Console Output Offset
ConSt_Offset	equ	33h		; "   Console Status Offset
SetTrk_Offset	equ	1Eh		; "   Jump Table Set Track Offset

HstDsk_Offset	equ	0		;Drive Number from Start of Apif
HstTrk_Offset	equ	1		;Track   "     "     "   "   "
HstSec_Offset	equ	3		;Sector  "     "     "   "   "
MftOff		equ	14		;format type in MTAB from dskdef1

Ex_Offset	equ	12		;Fcb offset to Extent
Cr_Offset	equ	32		; "    "    "  Current Record
OpFlag_Offset	equ	2Eh		;Offset to OpFlag from start of RamDatY

		;Length Definitions
L_Sector_Length	equ	80h		;Logical Sector Length
Descriptor_Leng	equ	9+15+1		;Combined Length of Mtab/Dpb (Md3 format)
Fcb_Length	equ	36		;Length of a Fcb
Fcb1		equ	5Ch		;Location of First Default Fcb
Dpb_Length	equ	15		;Define the length of a DPB
Max_Table	equ	( (MedEnd - MedTbl) / 4) - 1

		;Termination Codes
Again		equ	'A'		;Repeat previous format again
Restart		equ	'R'		;Restart format program
Exit		equ	Control_C	;Exit to Cp/m

		;Translation Table Code
morcod		equ	0		;Morrow D                                                                                                                                                                                                                                               tart w/Sector 0 not 1
$DBLMED		equ	00000100b	;Double Sided Media
$HRDDSK		equ	00000010b	;Hard Disk (used in drive selection)
@HrdDsk		equ	1		;Bit test for   "    "      "
@DblMed		equ	2		;Single/Double Sided Media Flag
$HdMsk		equ	00011100b	;Head Mask

		;MTAB's Dskdef1 Mask Bytes
$DEF1		equ	11111111b xor ($DRVDEN or $128 or $256 or $512 or $1024)
$DRVDEN		equ	00100000b	;Double Density Media
$128		equ	00000000b	;128 Bytes per Sector
$256		equ	00000001b	;256 Bytes per Sector
$512		equ	00000010b	;512 Bytes per Sector
$1024		equ	00000011b	;1024 Bytes per Sector
$SizMsk		equ	00000011b	;Sector Size Mask

		;Message Codes
Err_Cpm_Rev	equ	10		;Cpm Revision is NOT Cpm 3
Err_Ccp_Rev	equ	11		;Bios Compatability Rev too low
Err_Rom_Rev	equ	12		;Rom Revision is too low
No_Hard_Disk	equ	13		;Couldn't find a Hard Disk Mtab
No_Floppy_Disk	equ	14		;Couldn't find a Floppy Disk Mtab
Missing_CPM	equ	15		;Portions of CP/M are Missing
No_Free_Space	equ	16		;No Free Space Left
Bad_Media_ID	equ	17		;Media Definition Id Byte is Invalid.
General_Error	equ	18		;All Purpose Error Code

Msg_Banner	equ	20		;Title Banner
Msg_Reading	equ	21		;Reading from Floppy
Msg_Writing	equ	22		;Writing to Floppy
Msg_Pause	equ	23		;Pause for Input Prompt
Msg_CrLf	equ	60		;New Line

		;Non Printing Ascii Equates
Control_C	equ	03h		;Control C (Force CPM Warm Boot)
Bell		equ	07h		;Console Bell
BackSpace	equ	08h		;Back Space One Character
Tab		equ	09h		;Tab
Lf		equ	0Ah		;Line Feed
Cr		equ	0Dh		;Carriage Return
Clear_Screen	equ	1Ah		;Clear Screen
Esc		equ	1Bh		;Escape
Bright		equ	'('		;Hight Brightness
Dim		equ	')'		;Low Brightness

		;Other Equates
Sys_Disk_Buffer	equ	2800h		;System's Disk Buffer
Default_Dma	equ	80h		;Cpm Default Dma Address
;Response_Max	equ	10h		;Maximum Lengt                                                                                                                                                                                                                                               84)
;========================================
;
Backup_Main:
	ld	sp,Local_Stack		;Set the Stack Pointer

BuLp1:	ld	a,Msg_Banner		;Repeat
	call	Print_Message		;	Print the Opening Message

	call	Save_State		;	Save the Entry Conditions
	or	a			;	If (Can't find disk drives)
	jr	nz,Quit			;		Quit

	call	Check_Revision		;	Check Revisions and C-Level
	or	a			;	If (Wrong Revisions)
	jr	nz,Quit			;		Quit

	call	Make_a_Copy		;	Copy the Disk
	or	a			;	If (There was an Error)
	jr	nz,Quit			;		Quit

	call	Restore_a_Copy		;	Restore a Disk Copy
	or	a			;	If (There was an Error)
	jp	z,Ok			;		Quit

Quit:	cp	Control_C		;	If (Abort wasn't due to Control C)
	call	nz,Print_Message

Ok:	call	Restore_State		;Restore the Entry State
	jp	Bios_Entry		;Exit
	page

;======================================================================
; Get the Entry Conditions (23_Oct_84)
;=====================================
;	1) This routine saves the input file spec. (if any) and determines
;	   the numbers of the floppy and fixed (hard) drives by a call
;	   to Find_Drives.
;	2) Register Usage:
;		A  -> Returned 0 for NO Errors.
;		----> All other registers are destroyed
;
Save_State:
	ld	a,(Fcb1+1)		;If (the default Fcb is Active)
	cp	' '
	jr	z,SsSk1

	ld	hl,Fcb1			;	HL:= Source (User Fcb)
	ld	de,Default_Fcb		;	DE:= Destination (Save of Fcb)
	ld	bc,12			;	BC:= Length (only the name field)
	ldir				;	Save the Fcb

	ld	a,0FFh
	ld	(File_Active),a		;	Set File to Active

SsSk1:	ld	c,Bdos_Crnt_Disk	;Return the Current Disk Number
	call	Bdos_Entry
	ld	(Initial_Drive),a	;Save the Logged on Drive

	call	Find_Drives		;Find the Hard and Floppy Drives
	or	a			;If (Drives are missing)
	ret	nz			;	Return

	ld	a,(Fixed_Drive)
	inc	a			;	Convert to Absolute Drive Num                                                                                                                                                                                                                                               -----
;	1) This routine finds the First Hard Disk and the First Floppy Disk
;	   Drives in the System Mtabs.
;	2) Register Usage:
;		A  -> Returned 0 if both the hard and floppy drive found
;		----> All other registers are destroyed
;
Find_Drives:
	ld	a,EB_Get_Char_Tbl	;Read the Character Table
	call	Get_Buffer		;Read the Character Table
	ld	hl,Buffer		;HL:= Base of Character Table
	ld	de,Vnum_Offset		;DE:= Offset to Numb Log Drives
	add	hl,de
	ld	b,(hl)			;B:= Number of Drives

	push	bc
	ld	a,EB_Get_Mtabs
	call	Get_Buffer		;Read the System Mtabs
	pop	bc

	ld	a,0			;A:= Current Drive
FdLp1:	push	af
	call	Get_Mtab_Pntr		;Repeat	HL:= Pointer to DskDef0
	pop	af
	bit	@HrdDsk,(hl)		;	If (Current Drive eq Hard Disk)
	jr	nz,FdSk1		;		Break
	inc	a			;	Increment the Current Drive
	cp	b
	jr	nz,FdLp1		;Until (All Drives have been Checked)
	ld	a,No_Hard_Disk		;If (Hard Disk Not Found)
	ret				;	Return Error

FdSk1:	ld	(Fixed_Drive),a		;Install Hard Disk Drive Number
	ld	a,0			;A:= Current Drive
FdLp2:	push	af
	call	Get_Mtab_Pntr		;Repeat	HL:= Pointer to DskDef0
	pop	af
	bit	@HrdDsk,(hl)		;	If (Current Drive eq Floppy)
	jr	z,FdSk2			;		Break
	inc	a			;	Increment the Current Drive
	cp	b
	jr	nz,FdLp2		;Until (All Drives have been Checked)
	ld	a,No_Floppy_Disk	;If (Floppy Disk Not Found)
	ret				;	Return Error

FdSk2:	ld	(Floppy_Drive),a	;Save Floppy Disk Number
	ld	a,0			;A:= Ok Return Status
	ret				;Return
	page

;----------------------------------------------------------------------
; Get a Pointer to an Mtab (18_Oct_84)
;-------------------------------------
;	1) This routine returns the HL register pair pointing to the start
;	   of the mtab specified by the value of the accm. The Mtabs must
;	   have already been read into the Buffer                                                                                                                                                                                                                                               
	ld	d,0			;DE:= Floppy_Drive * 16
	ld	hl,Buffer		;HL:= Base of Mtabs
	add	hl,de			;HL:= Pointer to Start of Current Mtab
	ret
	page

;======================================================================
; Check Versions/Revisions (22_Oct_84)
;=====================================
;	1) This routine checks the CP/M version, the Bios Compatibility
;	   level and the Rom Revision Level.
;	2) Register Usage:
;		A  -> Returned 0 for NO Errors
;		----> All other registers are destroyed
;
Check_Revision:
	ld	c,Bdos_Ret_Ver		;C:= Return version Bdos call
	call	Bdos_Entry		;Get the Cpm Revision
	ld	a,0F0h
	and	l
	cp	30h			;If (this is NOT Cp/m 3)
	ld	a,Err_Cpm_Rev		;	A:= Error Code
	ret	nz			;	Return

	ld	a,EB_Get_Char_Tbl	;A:= Get Char Table Function
	call	Get_Buffer		;Read the Character Table
	ld	a,(Buffer+Ccl_Offset)
	cp	Ccl			;If (Compatibility Level NOT in Range)
	ld	a,Err_Ccp_Rev		;	A:= Error Code
	ret	c			;	Return

	ld	a,EB_ID_Frame		;A:= Read Rom ID Frame
	call	Extended_Bios		;Read the ID Frame
	ld	a,(Buffer+Rrl_Offset)
	cp	Rrl			;If (Rom Rev NOT in Range)
	ld	a,Err_Rom_Rev		;	A:= Error Code
	ret	c			;	Return

	ld	a,0			;A:= No Error
	ret				;Return
	page

;======================================================================
; Restore the Entry State (23_Oct_84)
;====================================
;	1) This routine restores the entry state of the machine by reselecting
;	   the drive that was active when the program started and by deleting
;	   the save file if appropriate.
;	2) Register Usage:
;		----> All registers are destroyed
;
Restore_State:
	ld	a,(Initial_Drive)
	ld	e,a			;E:= Drive to Select
	ld	c,Bdos_SelDsk		;C:= Select Disk Function
	call	Bdos_Entry		;Reselect the Entry Drive

	ld	a,(File_Active)		;If (the                                                                                                                                                                                                                                                ==============================================
; Make a Copy of a Floppy Disk (23_Oct_84)
;=========================================
;	1) If there was no input file specified then this routine builds
;	   one by reading the floppy disk. Only the file operations are
;	   done in this code section.
;	2) Register Usage:
;		A  -> Returned 0 for NO Errors
;		----> All registers are destroyed
;
Make_a_Copy:
	ld	a,(File_Active)		;If (File is Already Active)
	or	a
	ld	a,0			;	A:= No Error
	ret	nz			;	Return

	ld	a,Msg_Banner
	call	Print_Message		;Print Title Banner
	ld	a,Msg_Reading
	call	Print_Message		;Print Reading from Floppy
	call	Pause_for_Rtn		;Prompt User
	cp	Control_C		;If (Response eq Control C)
	ret	z			;	Return

;--------------------------------------------------------------------
; This section of Code Should be replaced by the 'Foreign' stub
; which should also ask the user if the copy file is to be saved.
	ld	hl,80
	ld	(Logical_Tracks),hl
	ld	hl,36
	ld	(Logical_Spt),hl
	ld	hl,9
	ld	(Physical_Spt),hl
	ld	hl,512
	ld	(P_Sector_Leng),hl

	call	Get_Media_Def		;Install Media Xlt, Mtab and Dpb
	or	a			;If (There was an Error)
	ret	nz			;	Return
;----------------------------------------------------------------------

	ld	hl,Default_Fcb		;HL:= Save Fcb
	ld	de,Fcb1			;DE:= Working Fcb
	ld	bc,Fcb_Length		;BC:= Length of Entire Fcb 
	ldir				;Install the Fcb

	ld	de,Buffer		;DE:= Start of Local Buffer
	ld	c,Bdos_Set_DMA		;C:= Set DMA Address Function
	call	Bdos_Entry		;Set the Dma Address

	ld	de,Fcb1			;DE:= Start of Command_Fcb
	ld	c,Bdos_Delete		;C:= Delete File Function
	call	Bdos_Entry		;Delete the Temp File

	ld	de,Fcb1			;DE:= Start of Command_Fcb
	ld	c,Bdos_Make_File	;C:= Open File Function
	call	Bdos_Entry		;Open the co                                                                                                                                                                                                                                               o FCB1
	ld	c,Bdos_Close_File	;C:= Close file function
	call	Bdos_Entry		;Close the command file
	pop	de

	cp	0FFh			;If (There was an Error)
	ld	a,General_Error		;	A:= Error Code
	ret	z			;	Return

	ld	a,d			;A:= Returned Status from Save_Disk
	ret				;Return
	page

;----------------------------------------------------------------------
; Save all Tracks on a Floppy Disk (23_Oct_84)
;---------------------------------------------
;	1) This routine builds the save file by repeatedly reading a floppy
;	   disk track and then writing it to the save file. The Number of
;	   Logical Tracks is used for loop control.
;	2) Register Usage:
;		A  -> Returned 0 for NO Errors
;		----> All registers are destroyed
;
Save_Disk:
	ld	hl,(Logical_Tracks)
	dec	hl
	ld	(Current_Track),hl	;Initialize Current_Track to Last Track

RdLp1:	ld	a,(Floppy_Drive)	;Loop
	ld	(Apif+HstDsk_Offset),a	;	Install The Drive Number

	call	Read_Flp_Track		;	Read a Track from the Floppy
	or	a			;	If (There was an Error)
	ret	nz			;		Return

	call	Write_Dsk_Track		;	Write the Track to the File
	or	a			;	If (There was an Error)
	ret	nz			;		Return

	ld	hl,(Current_Track)	;	If (Current_Track eq 0)
	ld	a,h
	or	l
	ret	z			;		Return

	dec	hl
	ld	(Current_Track),hl	;	Decrement the Current_Track
	jr	RdLp1
	page

;----------------------------------------------------------------------
; Read a Track from the Floppy Disk (23_Oct_84)
;----------------------------------------------
;	1) This routine reads a track from the Floppy Disk into the Local
;	   Buffer. The Number of Physical Sectors per Track is used for
;	   Loop Control
;	2) Register Usage:
;		A  -> Returned 0 for NO errors
;		----> All other registers are destroyed
;
Read_Flp_Track:
	ld	hl,(Current_Track)
	ld	(A                                                                                                                                                                                                                                                Sector

RdfLp1:	ld	hl,(Current_Sector)	;Repeat
	ld	(Apif+HstSec_Offset),hl	;	Install the Sector Number

   	ld	ix,Apif			;	IX:= Start of Local Apif
	ld	a,EB_Read_Host		;	A:= Read Host Function
	call	Extended_Bios		;	Read a Sector From Floppy Disk
	or	a			;	If (There was an Error)
	ld	a,General_Error		;		A:= Error Code
	ret	nz			;		Return

	ld	de,(P_Sector_Leng)	;	DE:= Length of One Sector
	ld	hl,(Current_Sector)	;	HL:= Current Sector
	dec	hl			;	(0 Based Sector Number)
	call	Multiply		;	HL:= Offset to Current Sector
	ld	de,Buffer		;	DE:= Start of the Buffer
	add	hl,de			;	HL:= Pointer to Sector Addr

	ex	de,hl			;	DE:= Destination (in Local Buffer)
	ld	hl,Sys_Disk_Buffer	;	HL:= Source (System Disk Buffer)
	ld	bc,(P_Sector_Leng)	;	BC:= Length (Length of 1 Sector)

	ld	a,EB_Get_Sys_Mem	;	A:= Read Disk Buffer Function
	call	Extended_Bios		;	Move the Sector Into Place

	call	Next_Phy_Sector
	or	a
	jr	nz,RdfLp1		;Until (All Sectors Have Been Read)
	ret				;Return
	page

;----------------------------------------------------------------------
; Write a Track to the Save File (23_Oct_84)
;-------------------------------------------
;	1) This routine moves the contents of the local buffer into the
;	   save file. The Number of Logical Sectors per Track is used
;	   for Loop Control.
;	2) Register Usage:
;		A  -> Returned 0 for NO Errors
;		----> All registers are destroyed
;
Write_Dsk_Track:
	ld	bc,(Logical_Spt)	;BC:= Logical Sectors/Track
	ld	de,Buffer		;DE:= Load Address

WfLp1:	push	bc
	push	de			;Repeat
	ld	c,Bdos_Set_DMA		;	C:= Set DMA Address Function
	call	Bdos_Entry		;	Set the Dma Address

	ld	de,Fcb1			;	DE:= Start of Command_Fcb
	ld	c,Bdos_Write_Seq	;	C:= Write Sequential Function
	call	Bdos_Entry		;	Write the Next record
	                                                                                                                                                                                                                                               	a,b
	or	c
	jr	nz,WfLp1		;Until (All sectors have been written)
	ret				;Return
	page

;======================================================================
; Restore a Disk from a File (23_Oct_84)
;=======================================
;	1) This routine takes care of initialization for the floppy restore
;	   process.
;	2) Register Usage:
;		A  -> Returned 0 for NO Errors.
;		----> All other registers are destroyed
;
Restore_a_Copy:
	ld	a,Msg_Banner
	call	Print_Message		;Print Title Banner
	ld	a,Msg_Writing
	call	Print_Message		;Print Writing to Floppy
	call	Pause_for_Rtn		;Prompt User
	cp	Control_C		;If (Response eq Control C)
	ret	z			;	Return

	ld	a,(File_Active)		;If (There was an Active Input File)
	or	a
	jr	z,RcSk1

;----------------------------------------------------------------------
; This section of code will be replaced by a read of the input file.
	ld	hl,80
	ld	(Logical_Tracks),hl
	ld	hl,36
	ld	(Logical_Spt),hl
	ld	hl,9
	ld	(Physical_Spt),hl
	ld	hl,512
	ld	(P_Sector_Leng),hl
;----------------------------------------------------------------------

RcSk1:	ld	hl,Default_Fcb		;HL:= Save Fcb
	ld	de,Fcb1			;DE:= Working Fcb
	ld	bc,Fcb_Length		;BC:= Length of Entire Fcb 
	ldir				;Install the Fcb

	ld	de,Buffer		;DE:= Start of Local Buffer
	ld	c,Bdos_Set_DMA		;C:= Set DMA Address Function
	call	Bdos_Entry		;Set the Dma Address

	ld	de,Fcb1			;DE:= Start of Command_Fcb
	ld	c,Bdos_Open_File	;C:= Open File Function
	call	Bdos_Entry		;Open the command file
	cp	0FFh			;If (file can't be opened)
	ld	a,General_Error		;	General Error Code
	ret	z			;	Return

	call	Restore_Disk		;Restore the Contents of a Floppy
	ld	d,a			;(D:= Returned Status)

	push	de
	ld	de,Fcb1			;DE:= Pointer to FCB1
	ld	c,Bdos_Close_File	;C:= C                                                                                                                                                                                                                                               -----------------------------------------------------------------
; Restore All Tracks on a Floppy Disk from the Save File (22_Oct_84)
;-------------------------------------------------------------------
;	1) This routine restores all of the tracks on a floppy disk from
;	   the save file. The number of Logical Tracks is used as for
;	   loop control.
;	2) Register Usage:
;		A  -> Returned 0 for NO Errors.
;		----> All other registers are destroyed
;
Restore_Disk:
	ld	hl,(Logical_Tracks)
	dec	hl
	ld	(Current_Track),hl	;Initialize Current_Track to Last Track

WrLp1:	ld	a,(Floppy_Drive)	;Loop
	ld	(Apif+HstDsk_Offset),a	;	Install The Drive Number

	call	Read_Dsk_Track		;	Read a Track from the Save File
	or	a			;	If (There was an Error)
	ret	nz			;		Return

	call	Write_Flp_Track		;	Write the Track to the Floppy
	or	a			;	If (There was an Error)
	ret	nz			;		Return

	ld	hl,(Current_Track)	;	If (Current_Track eq 0)
	ld	a,h
	or	l
	ret	z			;		Return

	dec	hl
	ld	(Current_Track),hl	;	Decrement the Track Count
	jr	WrLp1
	ret				;Return
	page

;----------------------------------------------------------------------
; Read a Track from the Save File (23_Oct_84)
;--------------------------------------------
;	1) This routine reads a floppy track from the save file into the
;	   local buffer. The number of logical sectors per track is used
;	   as the loop control.
;	2) The direct bios call to reselect the disk is required because
;	   the floppy disk format entry causes the bios to assume that the
;	   the floppy disk is currently selected.
;	3) Register Usage:
;		A  -> Returned 0 for NO Errors.
;		----> All other registers are destroyed
;
Read_Dsk_Track:
	ld	bc,(Logical_Spt)	;BC:= Logical Sectors/Track
	ld	de,Buffer 		;DE:= Load Address

                                                                                                                                                                                                                                               rameters
	ld	c,Bdos_Direct		;	C:= Direct Bios Call
	call	Bdos_Entry		;	Reselect the Hard Disk

	ld	de,Fcb1			;	DE:= Start of Command_Fcb
	ld	c,Bdos_Read_Seq		;	C:= Read Sequential Function
	call	Bdos_Entry		;	Read the Next record
	pop	de
	pop	bc

	or	a			;	If (There was an Error)
	ld	a,General_Error		;		A:= Error Code
	ret	nz			;		Return

	ld	hl,L_Sector_Length
	add	hl,de
	ex	de,hl			;	DE:= Next Sector Address

	dec	bc			;	Decrement the Sector Length
	ld	a,b
	or	c
	jr	nz,RfLp1		;Until (All sectors have been read)
	ret				;Return
	page

;----------------------------------------------------------------------
; Write a Track to the Floppy Disk (23_Oct_84)
;---------------------------------------------
;	1) This routine writes one Track to the Floppy Disk from the local
;	   buffer. Before the track is written it is formatted. After the
;	   track is written it is verified.
;	2) Register Usage:
;		A  -> Returned 0 for NO Errors.
;		----> All other registers are destroyed
;
Write_Flp_Track:
	ld	hl,(Current_Track)
	ld	(Apif+HstTrk_Offset),hl	;Initialize the Track Number
	ld	a,Cr
	call	Put_Character
	call	Print_Number

	;Format the Track
	ld	hl,Fmt_Gap_Skew
	ld	(Apif+HstSec_Offset),hl	;Install the Gap/Skew Pointer

	ld	ix,Apif			;IX:= Pointer to Local Apif
	ld	de,Fmt_Mtab_Dpb		;DE:= Pointer to Mtab/Dpb
	ld	a,EB_Format		;A:= Format a Track Function
	call	Extended_Bios		;Format the Track

	ld	a,d			;A:= Returned Status
	or	a			;If (There was an Error)
	ld	a,General_Error
	ret	nz			;	Return

	;Write the Track
	ld	hl,(Physical_Spt)
	ld	(Sector_Count),hl	;Initialize the Sector Count
	ld	hl,1
	ld	(Current_Sector),hl	;Initialize the Current Sector

WrfLp1:	ld	hl,(Current_Sector)	;Repeat
	ld	(Apif+HstSec_Offset),hl	;	Install the Se                                                                                                                                                                                                                                               er
	add	hl,de			;	HL:= Source (in Local Buffer)

	ld	de,Sys_Disk_Buffer	;	DE:= Destination (Sys Buffer)
	ld	bc,(P_Sector_Leng)	;	BC:= Length (Length of 1 Sector)

	ld	a,EB_Put_Sys_Mem	;	A:= Write to System Memory
	call	Extended_Bios		;	Move Buffer into Disk Buffer

	ld	ix,Apif			;	IX:= Local APIF
	ld	a,EB_Write_Host		;	A:= Write Host Function
	call	Extended_Bios		;	Write a Sector to the Disk
	or	a			;	If (There was an Error)
	ld	a,General_Error		;		General Error Code
	ret	nz			;		Return

	call	Next_Phy_Sector		;	Get the Next Sector
	or	a
	jr	nz,WrfLp1		;Until (All Sectors have been Written)

	;Verify the Track
	ld	bc,(Current_Track)	;BC:= Current Track
	lä	hl,(Bios_Entry+1)
	ld	l,SetTrk_Offset		;HL:= Vector to SetTrk
	ld	a,EB_Execute		;A:= Execute in the System Bank
	call	Extended_Bios		;Set the Track Number (in BC)

	ld	a,EB_Verify_D		;A:= Verify Destructive
	call	Extended_Bios		;Verify the Track
	ld	a,d			;A:= Returned Error Status
	or	a			;If (There was an Abort)
	ld	a,General_Error		;	A:= Error Code
	ret	nz			;	Return

	ld	a,0			;Else	A:= No Error
	ret				;	Return
	page

;----------------------------------------------------------------------
; Calculate the Next Physical Sector (17_Oct_84)
;-----------------------------------------------
;	1) This routine checks if all the sectors have been accessed and
;	   adjusts the next sector accordingly (based on a skew of 2).
;	2) Register Usage:
;		A  -> Returned 0 for last sector.
;		HL -> Returned equal to the Current Sector Number
;		----> No other registers are effected
;
Next_Phy_Sector:
	ld	hl,(Sector_Count)
	dec	hl
	ld	(Sector_Count),hl	;Decrement the Sector Count
	ld	a,h			;If (All Sectors have Been Accessed)
	or	l
	ret	z			;	Return

	ld	hl,(Current_Sector)
	inc	hl
	i                                                                                                                                                                                                                                               s)
	pop	de
	pop	hl

	ret	c			;	Return
	ret	z

	ld	hl,2			;Else
	ld	(Current_Sector),hl	;	Current_Sector:= 2
	ret				;	Return
	page

;----------------------------------------------------------------------
; Get the Media Definiton Table (19_Oct_84)
;------------------------------------------
;	1) This routine gets the media definition table
;
Get_Media_Def:
	ld	a,2			;A:= Default (Ibm 9 Spt Double Sided)
	call	Install_Drive		;Install the Drive

	ld	a,(Floppy_Drive)
	ld	(Apif+HstDsk_Offset),a	;Install the Drive Number
	ld	hl,0
	ld	(Apif+HstTrk_Offset),hl	;Install the Track Number
	ld	hl,2
	ld	(Apif+HstSec_Offset),hl	;Install the Sector Number

	ld	ix,Apif
	ld	a,EB_Read_Host
	call	Extended_Bios		;Read the Second Sector of the Disk
	or	a			;If (There was NO Read Error)
	jr	nz,GmSk2

	ld	a,EB_Get_Sys_Mem	;	A:= Read From System Memory
	ld	hl,Sys_Disk_Buffer	;	HL:= Source (System Disk Buffer)
	ld	de,Buffer		;	DE:= Destination (Local Buffer)
	ld	bc,10			;	BC:= Length (only need one)
	call	Extended_Bios		;	Read 1st 10 bytes of Disk Buffer

	ld	a,(Buffer)		;	Get the ID Byte from the Fat
	xor	0FFh			;	Convert it to a code (0 to 3)
	cp	4
	jr	c,GmSk1

	ld	a,Bad_Media_ID		;		A:= Media Id Invalid.
	ret				;		Return

GmSk1:	call	Install_Drive		;	Install the Drive
	ret				;	Return (Status set by Install)

GmSk2:	ld	a,4			;Else	A:= Morrow Double Sided Format
	call	Install_Drive		;	Install the Drive
	ld	a,(Floppy_Drive)
	ld	e,a			;	E:= Disk Number
	ld	c,Bdos_SelDsk		;	C:= Select Disk Function
	call	Bdos_Entry		;	Select the Disk
	ret				;	Return (Status set by SelDsk)
	page

;======================================================================
; Install a Foreign/Native Drive (19_Oct_84)
;===========================================
;
                                                                                                                                                                                                                                               e dph
	call	Install_Dpb		;	Overlay the Dpb
	call	Install_Mtab		;	Update the drive's MTAB
	ld	a,0			;	A:= No Error
	ret				;	Return

;----------------------------------------------------------------------
; Install the Disk Parameter Template (19_Oct_84)
;------------------------------------------------
;
Install_Table:
	sla	a
	sla	a			;Input_Number:= Input_Number * 4
	ld	c,a
	ld	b,0			;BC:= Offset to the entry
	ld	hl,MedTbl		;HL:= Base of Media Table
	add	hl,bc			;HL:= Start of the desired table
	ld	e,(hl)
	inc	hl
	ld	d,(hl)			;DE:= Starting Address of Media Table
	inc	hl
	ld	c,(hl)
	inc	hl
	ld	b,(hl)			;BC:= Length of table
	ex	de,hl			;HL:= Starting Address of Media Table
	ld	de,dsk0			;DE:= Start of the Media Table Template
	ldir				;Move Parameter Template into Place
	ret				;Return
	page

;----------------------------------------------------------------------
; Install the translate table for this drive (4_Jan_84)
;------------------------------------------------------
;	1) Drives with no translation tables return Immediately (with accm=0).
;	2) If the table was found or successfully installed then the accm is
;	   returned equal to zero.
;	3) If there was insufficient room in the table for the new translate
;	   table or the program failed to find a native drive then the accm
;	   is returned non-zero.
;	4) Register Usage:
;		A  -> General Purpose
;		BC -> Length for moves
;		DE -> Pointer to Xtl - 1
;		HL -> Pointer into free space
;
Install_Xlt:
	ld	de,(xltlen)		;If (the drive has NO translate table)
	ld	a,d
	or	e
	ret	z			;	Return (status 0 = ok)

	ld	a,EB_Get_Free		;	A:= Function_8 (get free space)
	call	Get_Buffer		;	HL:= Pointer to Start Free Space
	ex	de,hl

	;Search for a matching xlt or the end of the free spa                                                                                                                                                                                                                                               s

skip1:	ld	a,0FFh			;	A:= End of Table code
	cp	(hl)			;	If (entry type eq EOT)
	jr	nz,skip3

	ld	a,(dsk0)		;		If (drive eq foreign)
	and	$FRGN
	jr	nz,skip2
	ld	a,Missing_CPM		;			A:= Error Code
	call	Print_Message		;			Print the Error
Fatalº	jð	Fataì			»			Hang: Fataì Error

	;Enter the Translate table into the free space pool
skip2:	call	Enter_Xlt		;		enter the new xlt table
	or	a			;		If (entry could not be made)
	ret	nz			;			Return (error)

	;Generate the System's address for the new translate table
SXout:	inc	de
	ex	de,hl			;		HL:= Start of Xtl in loc buf
	ld	de,Buffer		;		DE:= Start of Local Buffer
	or	a			;		(clear the carry)
	sbc	hl,de			;		HL:= Offset from start Loc Buf
	ld	de,(Save_DE)		;		DE:= Start of system free space
	add	hl,de			;		HL:= Pointer to xtl in free space
	ld	(Save_DPH),hl		;		Save Xlt Pointer

	call	Put_Buffer		;		ReWrite free space to sys mem
	ld	a,0
	ret				;		Return (no error)

	;Move the pointer to the start of the next entry
skip3:	inc	hl			;