TITLE	HDC-1001 HARD DISK FORMATTER 

;--------------------------------
; AUTHOR  Marcus G. Calescibetta
; DATE    March 5, 1984
; VERSION 2.4
;--------------------------------

	.z80

;-------------------
; CHARACTER EQUATES
;-------------------

CR	EQU	00DH			; Carriage return
LF	EQU	00AH			; Line feed
BS	EQU	008H			; Back space

;---------------------
; BDOS FUNCTION CALLS
;---------------------

BDOS	EQU	005H			; BDOS entry point
PRTSTR	EQU	009H			; Print string
CONIN	EQU	001H			; Console input
CONOUT	EQU	002H			; Console output
RDBUF	EQU	00AH			; Read console buffer
CONST	EQU	00BH			; Console status

;----------------------------------
; HDC-1001 REGISTER PORT ADDRESSES
;----------------------------------

HDBASE	EQU	0E0H			; HDC1001 base I/O port
DATA	EQU	HDBASE+0		; Data register
ERROR	EQU	HDBASE+1		; Error register
PRECOMP	EQU	HDBASE+1		; Write pre-compensation register
SECNT	EQU	HDBASE+2		; Sector count register
SECNO	EQU	HDBASE+3		; Sector number register
CYLLO	EQU	HDBASE+4		; Cylinder low register
CYLHI	EQU	HDBASE+5		; Cylinder high register
SDH	EQU	HDBASE+6		; Size/Drive/Head register
COMND	EQU	HDBASE+7		; Command register
STATUS	EQU	COMND			; Status register

;-------------------
; HDC-1001 COMMANDS
;-------------------

CREST	EQU	10H			; Restore heads
CREAD	EQU	20H			; Read sector
CWRITE	EQU	30H			; Write sector
CFORM	EQU	50H			; Format track

	ASEG
	ORG	0100H

;------------------
; START OF PROGRAM
;------------------

start:	
	ld	de,signon		; send signon message
	ld	c,prtstr		; display message at console
	call	bdos			; 
getdrv:
	ld	de,inbuf		; get response to disk type
	ld	c,rdbuf			; input line of characters from console
	call	bdos			; put response in inbuf

	ld	a,(numchr)		; check no. of chars ret 1 or 2
	cp	0			; check for zero chars returned
	jr	z,bad			; if zero jump to invalid response 
	cp	3			; check for three chars returned
	jr	c,good			; if not then chars ret is 1 or 2
bad:	
	ld	de,inval		; display invalid response 
	ld	c,prtstr		; send message to console
	call	bdos			;

	ld	de,menu			; display drive menu again
	ld	c,prtstr		; send it to console
	call	bdos			;
	jr	getdrv			; jump to recieve response

;-------------------------
; CONVERT ASCII TO BINARY
;-------------------------

good:	
	ld	de,inttbl		; set up registers
	ld	hl,0			; inttbl contains user responce
declp:	
	push	af			; sav char cnt (no of chars to convert)
	ld	a,(de)			; get a char 
	inc	de			; point to next char to fetch	
	cp	'0'			; check to make sure char is numeric
	jp	c,bad			; jmp to invalid responce if < 0
	cp	'9'+1			; check for > 9
	jp	nc,bad			; if char  > 9 then invalid responce 
	sub	'0'			; convert from ascii to binary

	ld	b,h			; mult present value * 10
	ld	c,l			; save it first in bc
	add	hl,hl			; *2
	add	hl,hl			; *4
	add	hl,bc			; *5
	add	hl,hl			; *10
	add	a,l			; add in new value
	ld	l,a			; save it in hl
	jp	nz,dignc		; check for l reg overflow 
	inc	h			; if overflow then inc h
dignc:	
	pop	af			; return char count to a reg
	dec	a			; decrement char cnt 
	jp	nz,declp		; check if done with conversion

;--------------------------
; CHECK IF CARTRIAGE DRIVE
;--------------------------

	push	hl			; save drive menu no.
	ld	a,014h			; drive  no. 20 is a cartriage drive 
	cp	l			; check if drive selection is 20
	jp	nz,getpar		; if not then jump out 
cart:	
	ld	de,carmsg		; if here then cart drv selected
	ld	c,prtstr		; ask if format cart only
	call	bdos			; send if to console

	ld	c,conin			; get responce to format cart only
	call	bdos			; from console

	and	05fh			; convert reply to uppercase
	cp	'B'			; check if negative response
	jp	z,getpar		; jump out if format entire drive

	cp	'C'			; check if positive reply
	jp	nz,fixed
	ld	a,1
	ld	(dmahds),a
	jp	getpar
fixed:
	cp	'F'
	jp	nz,cart
	ld	a,1
	ld	(hdmsk),a

;----------------------
; GET DRIVE PARAMETERS
;----------------------

getpar:	
	pop	hl			; restore drive menu no.
	ld	d,h			; save it in de
	ld	e,l			; mult *6 to index into drv par tbl
	add	hl,hl			; *2
	add	hl,de			; *3
	add	hl,hl			; *6
	ld	de,dskprms		; add in base addr of drv par tbl
	add	hl,de			; hl now pnts to correct entry
	ld	de,secs			; now move parms to prog use locs
	ld	bc,6			; 6 bytes in dskpar tlb entry
	ldir

;------------------------
; GET PHYSICAL DRIVE NO.
; -----------------------

drvin:	
	ld	de,drvmsg		; ask which phy drv to format
	ld	c,prtstr		; send msg to console
	call	bdos

	ld	c,conin			; get response from console
	call	bdos			;

	sub	'0'			; convert ascii to binary
	cp	004h			; check if < 4
	jr	c,goodr			; jmp if reply ok
	ld	de,inval		; otherwise invalid response 
	ld	c,prtstr		; send bad reply message 
	call	bdos			; send it to the console
	jr	drvin			; try again
goodr:	
	ld	(unit),a		;save drive

;-------------
; QUIT FORMAT
;-------------

	ld	de,q1			; msg states this will destroy all data
	ld	c,prtstr		; on drive 
	call	bdos			; 

	ld	a,(unit)		; display drive no. selected 
	call	outchr			; covert to ascii, then send to console

	ld	de,q2			; display prompt asking if to procede
	ld	c,prtstr		;
	call	bdos			;

	ld	c,conin			; get response
	call	bdos			;
	cp	cr			; if carriage return input then 
	jp	z,doit			; format drive
abort:	
	ld	de,abtmsg		; user changed their mind
	ld	c,prtstr		; display no format performed msg
	call	bdos			;
	jp	resel			; return to cpm
doit:	
	ld	de,formsg		; display formatting drv msg
	ld	c,prtstr		;
	call	bdos			;

;----------------------------
; CALCULATE INTERLEAVE TABLE
;----------------------------

	ld	B,040h			; make tbl max size, using 1 byt/sec 
	ld	hl,inttbl		; point to interleave table
setlp:	
	ld	(hl),0ffh		; set all cells in tbl to 0ffh
	inc	hl			; point to next cell
	dec	b			; decrement tbl count
	jp	nz,setlp		; loop unti finished with initalization
;
;	Generate 16 bit interleave
;
	ld	hl,(interb)		; Get interleave byte
	ld	h,0			; and turn it into a word
	ld	(inter),hl
;
;	Next, calculate interleave table upper limit
;
	ld	a,(secs)		; Get number of sectors
	ld	b,a			; Save for later
	ld	e,a			; Offset off base of int table
	ld	d,0
	ld	hl,inttbl
	add	hl,de
	ld	a,l			; Negate (2s complement)
	cpl	
	ld	l,a
	ld	a,h
	cpl	
	ld	h,a			; This is our upper limit
	inc	hl
	ld	(limit),hl
;
;	Now, negative sector count
;
	ld	a,b			; Get sectors per track (SECS)
	cpl				; And twos complement
	ld	l,a
	ld	h,0ffh
	inc	hl
	ld	(nsecs),hl
;
;	Calculate interleave table
;
	ld	b,0			; Clear sector number
	ld	de,inttbl		; Index interleave table
check:	
	ld	hl,(limit)		; Make sure limits not exceeded
	add	hl,de
	jp	nc,within		; We are within limits
	ld	hl,(nsecs)		; Otherwise subtract SECS
	add	hl,de
xcheck:	
	ex	de,hl
	jp	check			; And check limits again
within:	
	ld	a,(de)			; This place taken?
	and	a
	jp	m,gotit			; If not, we can use it
	inc	de			; Else, check next one
	jp	check
gotit:	
	ld	a,b			; Store sector number
	ld	(de),a
	ld	hl,(inter)		; Increment pointer by
	add	hl,de			; interleave
	inc	b			; Increment sector count
	ld	a,(secs)		; Have we done enough?
	cp	b
	jp	nz,xcheck

;---------------------
; RESTORE DRIVE HEADS
;---------------------

	ld	a,(sizmsk)		; set up sdh register first
	ld	b,a			; get sdh register sector size mask    
	ld	a,(unit)		; get drive no
	rlca				; rotate it to its proper position     
	rlca				; for sdh register this is bits 3,4    
	rlca				; 
	or	b			; or in sector size
	ld	(unit),a		; save it for future refrence
	out	(sdh),a			; send it to sdh register

	ld	a,(stprte)		; get step rate
	ld	b,a                     ; save it in b
	ld	a,crest                 ; load a with a restore command
	or	b                       ; or in step rate
	out	(comnd),a               ; send command to controller
rswait:	                                  
	in	a,(status)              ; wait until controller done w. restore
	and	a                       ; check busy bit, bit 8 
	jp	m,rswait                ; loop until not busy
	bit	4,a
	jr	z,rswait
	
;--------------
; FORMAT DRIVE
;--------------

	ld	hl,(cyls)		; get last cylinder
	push	hl			; save it as current cylinder
headlp:	
	call	cylprt			; print current cylinder
	ld	a,(heads)		; get last head
	ld	d,a			; save it in d
	ld	a,0ah			; initalize retry count 
	ld	(retry),a		; ten retrys per format track
forlp:
	push	de			; save current head no.

	ld	a,d			; display head that we are on
	call	outchr

	ld	e,bs			; backspace to begining of head info
	ld	c,conout		; send bs to console
	call	bdos			;

	pop	de			; restore current head no.

	ld	a,(secs)		; get sector count
	out	(secnt),a		; send it to sector count register

	pop	hl			; restore current cyl no.
	push	hl			; save current cyl no.

	ld	a,l			; put cyl low in a
	out	(cyllo),a		; send it to cylinder low register

	ld	a,h			; put cyl high in a
	out	(cylhi),a		; send it cylinder high register

	ld	a,(unit)		; get sector size, and unit no.
	or	d			; or in heads
	out	(sdh),a			; send it to sdh register

	ld	a,cform			; issue format command
	out	(comnd),a		; send it to command register
dwait:
	in	a,(status)		; wait for data request	
	and	008H			; by checking data req bit, bit 2 
	jr	z,dwait			; loop until data requested
	
;-------------------------
; SET UP FOR FORMAT TRACK
;-------------------------

	ld	hl,inttbl		; point to interleave table
siz512:
	ld	b,0			; set up b-reg to contain (secsiz / 2)
	ld	a,(sizmsk)		; check if 512 byte sectors
	cp	020h			; sdh reg settin =020h if 512 bps 
	jr	z,sizok			; jump over 256 bps setting
siz256:
 	ld	b,080H			; else set up for 256 bps      
sizok:
	ld	a,data			; because we snd 2 byts per iteration
	ld	c,a			; data register port goes in c
	xor	a			; set up bad block byte

;-----------------------------------------
; SEND FORMAT DATA TO HDC-1001 CONTROLLER
;-----------------------------------------

datalp:
	out	(c),a			; send bad block byte to controller
	outi				; send interleave tbl byte to cont
	jr	nz,datalp		; loop untill sector size transfered
fwait:
	in	a,(status)		; wait until done with format cmd
	and	a			; by checking busy bit, bit 8
	jp	m,fwait			; loop until controller not busy
	bit	4,a
	jr	z,fwait

	rra				; check error bit, bit 0 set
	jp	nc,fmtok		; jmp over retry if no error
	
	ld	a,(retry)		; get format retry count
	dec	a			; decrement count
	ld	(retry),a		; save new retry count
	jp	m,herror		; jmp if pased limit
	jp	forlp			; else retry format
fmtok:
	call	xitck			; check it control c has been typed

	dec	d			; bump head counter
	ld	a,(hdmsk)
	xor	d
	jp	nz,forlp		; passed head 0 or 2, depends on msk

	pop	hl			; restore current cylinder
	dec	hl			; bump cylinder count
	ld	a,h			; have we passed cyl 0 yet
	and	a			; if = -1, then bit 7 in h set 
	push	hl			; save current cylinder
	jp	p,headlp		; jmp to format new cyl, reset hd cnt
	pop	hl			; clear stack

;------------------------
; VERIFY DRIVE TRACK IDS
;------------------------

	ld	de,vermsg		; display verifying drive msg
	ld	c,prtstr		; send to console
	call	bdos			;

	ld	hl,(cyls) 		; get cylinder count
	ld	a,(heads)		; get head count
	ld	e,a			; save it in e
	ld	a,(secs)		; get sector count
	dec	a			; decrement sector so numbered from 0
	ld	d,a			; save it in d
rhead:	
	call	cylprt			; print current cylinder no
	ld	c,e			; Reload head
rsecs:	
	push	hl			; save current cylinder
	push	de			; save head and sector count
	push	bc			; save current head and sector no.

	ld	a,c			; Output head that we are on
	call	outchr
	ld	e,bs
	ld	c,conout
	call	bdos

	pop	bc			; restore cur hd and sec 
	pop	de			; restore hd and sec cnt
	pop	hl			; restore cur cylinder

	ld	b,d			; reload cur sector w. sec cnt
readit:	
	ld	a,b			; load current sector no.
	out	(secno),a		; send it to sector no. register

	ld	a,l			; load current cylinder low
	out	(cyllo),a		; send to cylinder low reg

	ld	a,h			; load current cylinder high
	out	(cylhi),a		; send to cylinder high reg

	ld	a,(unit)		; load sector size and phy drive
	or	c			; OR in current head no
	out	(sdh),a			; send to sdh reg

	ld	a,cread			; load a read command
	out	(comnd),a		; send to command reg
rwait:	
	in	a,(status)		; wait for controller to read sec
	and	040H			; check ready bit, bit 6
	jp	z,rwait			; loop until controller ready

	in	a,(status)		; check for errors during read
	rra				; error bit, bit 0
	jp	nc,noerr		; jump over if no errors

;----------------------
; PRINT ERROR MESSAGES
;----------------------

	push	hl			; save current cylinder  
	push	de			; save sector and head count	
	push	bc			; save save current sector and head

	ld	de,errst		; send start of error message
	ld	c,prtstr		;
	call	bdos			;

	in	a,(error)		; read error register
	call	hexout			; display contents in hex

	ld	de,errhd		; point to head literal
	ld	c,prtstr		; display on console
	call	bdos			;

	in	a,(sdh)			; read sdh register
	and	7			; mask for current head no
	call	outchr			; display single digit

	ld	de,errcyl		; point to cylinder literal
	ld	c,prtstr		; display on console
	call	bdos			; display 'cylinder'

	in	a,(cylhi)		; get cylinder high value
	call	hexout			; display it in hex

	in	a,(cyllo)		; get cylinder low value
	call	hexout			; display it in hex

	ld	de,errsec		; point to sector literal
	ld	c,prtstr		; display on cosole
	call	bdos			; display 'sector'

	in	a,(secno)		; read current sector no 
	call	hexout			; display value in hex

	ld	de,vermsg1		; send lf to console
	ld	c,prtstr		;
	call	bdos			;

	call	cylprt			; display cyl head sec again for fmt lp

	pop	bc			; restore current sec and hd
	pop	de			; restore sec and head cnt
	pop	hl			; restore cyl cnt 

;----------------------------------------
; DECREMENT SECTOR, HEAD AND/OR CYLINDER 
;----------------------------------------

noerr:	
	call	xitck			; check if control c typed
	dec	b			; decrement current sector number
	jp	p,readit		; jump to read next sector

	dec	c			; decrement current head no
	ld	a,(hdmsk)
	xor	c
	jp	nz,rsecs		; jump to reset sectors 

	dec	hl			; decrement cylinder number
	ld	a,h			; check if -1
	and	a			; look at bit 7 in h
	jp	p,rhead			; jump to reset heads

	ld	de,dnemsg		; display formating complete
	ld	c,prtstr		;
	call	bdos			;

	jp	resel			; Reselect original drive

;------------
; EXIT CHECK
;------------

xitck:	
	push	hl			; save regs
	push	de
	push	bc

	ld	c,const			; get console status
	call	bdos			; bdos call 0bh
	and	a			; bdos returns 0 if no char pending
	jr	z,skp			; skip if no char else bdos ret a 0ffh
	ld	c,conin			; get char typed
	call	bdos			; 

	cp	3			; check for control c
	jp	z,abort			; if so restart sys
skp:	

	pop	bc			; restore registers
 	pop	de			;
	pop	hl			;
	ret

;----------------------------------
; PRINT HEXADECMIAL VALUE OF A-REG
;-----------------------------------

hexout:	
	push	af			; save a-reg
	rrca				; rotate 4 most significant bits
	rrca				; 2
	rrca				; 3 
	rrca				; 4
	
	call	outchr			; Print upper digit

	pop	af			; restore value to display
outchr:	
	and	00fh			; mask least significant four bits
	add	a,'0'			; add in ascii offset
	cp	'9'+1			; check if > 10
	jp	m,sndchr		; if no the char ok
	add	a,07h			; else add in offset to make a-f
sndchr:
	ld	e,a			; store result in e for bdos
	ld	c,conout		; send it to console
	call	bdos			;
	ret	

;---------------------------
; PRINT CYLINDER ON CONSOLE
;---------------------------

cylprt:	
	push	de			; save registers
	push	bc			;
	push	hl			;

	ld	de,bsmsg		; back up to start of cyl column
	ld	c,prtstr		; 
	call	bdos			;

	pop	hl			; get cylinder from stack
	push	hl			; put it back
	ld	a,h			; display cylinder high 
	call	hexout			; in hex

	pop	hl			; get current cylinder from stack
	push	hl			; put it back on stack
	ld	a,l			; display cylinder low 
	call	hexout			;

	ld	de,hdmsg		; display head msg
	ld	c,prtstr		;
	call	bdos			;

	pop	HL			;restore regs
	pop	bc
	pop	de
	ret

;----------------------
; PRINT ERROR MESSAGES
;----------------------

herror:
	in	a,(status)		; read status register
	and	020h			; check for write fault first
	jr	z,ckereg		; jump if no write fault error

	ld	de,wrtflt		; address of write fault error msg 
	ld	c,prtstr		; function to print string on con
	call	bdos			; do it
ckereg:
	in	a,(error)		; read error register
	ld	hl,errmsg		; base address of messages
	ld	de,019h			; message length
	ld	b,008h			; number of possible errors 
tstbit:
	rra				; rotate a bit into carry
	jr	nc,nxbit		; jump if bit not set (no error)

	push	hl			; if here then error bit set
	push	de			; print error via bdos
	push	bc			; bdos clobbers registers 
	push	af			; save current state
	ex	de,hl			; hl has curren error bit msg addr
	ld	c,prtstr		; print string function
	call	bdos			; print error message on console
	pop	af			; restore registers
	pop	bc			;
	pop	de			;
	pop	hl			;
nxbit:
	add	hl,de			; make hl point to next error message
	dec	b			; decrement error bit counter
	jr	nz,tstbit		; jump to test next error bit
resel:	
	jp	0	

;--------------
; DATA STORAGE
;--------------

ERRMSG:
	DB	cr,lf,'DAM Not Found Error   ','$'
	DB	cr,lf,'TR000 Error           ','$'
	DB	cr,lf,'Aborted Command Error ','$'
	DB	cr,lf,'Undefined Error       ','$'
	DB	cr,lf,'ID Not Found Error    ','$'
	DB	cr,lf,'CRC Id Error          ','$'
	DB	cr,lf,'Uncorrectable Error   ','$'
	DB	cr,lf,'Bad Block Detect Error','$'
WRTFLT:	
	DB	cr,lf,'Write Fault Error     ','$'

;----------------------
; DISK PARAMETER TABLE
;----------------------

DSKPRMS:
ST503:					; 0.
	DB	16			; sectors
	DW	152			; cylinders-1
	DB	1			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
ST506:					; 1.
	DB	16			; sectors
	DW	152			; cylinders-1
	DB	3			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
TM601s:					; 2.
	DB	16			; sectors
	DW	152			; cylinders-1
	DB	1			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
TM602s:					; 3.
	DB	16			; sectors
	DW	152			; cylinders-1
	DB	3			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
TM603s:					; 4.
	DB	16			; sectors
	DW	152			; cylinders-1
	DB	5			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
TM603se:				; 5.
	DB	16			; sectors
	DW	229			; cylinders-1
	DB	5			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
TM501:					; 6.
	DB	16			; sectors
	DW	305			; cylinders-1
	DB	1			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
TM502:					; 7.
	DB	16			; sectors
	DW	305			; cylinders-1
	DB	3			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
TM503:					; 8.
	DB	16			; sectors
	DW	305			; cylinders-1
	DB	5			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
SA602:					; 9.
	DB	16			; sectors
	DW	159			; cylinders-1
	DB	1			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
SA604:					; 10.
	DB	16			; sectors
	DW	159			; cylinders-1
	DB	3			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
SA606:					; 11.
	DB	16			; sectors
	DW	159			; cylinders-1
	DB	5			; heads-1
	DB	020h			; sector size mask
	DB	6			; step rate
SA1002:					; 12.
	DB	16			; sectors
	DW	255			; cylinders-1
	DB	1			; heads-1
	DB	020h			; sector size mask
	DB	0			; step rate
SA1004:					; 13.
	DB	16			; sectors
	DW	255			; cylinders-1
	DB	3			; heads-1
	DB	020h			; sector size mask
	DB	0			; step rate
Q2010:					; 14.
	DB	16			; sectors
	DW	511			; cylinders-1
	DB	1			; heads-1
	DB	020h			; sector size mask
	DB	0			; step rate
Q2020:					; 15.
	DB	16			; sectors
	DW	511			; cylinders-1
	DB	3			; heads-1
	DB	020h			; sector size mask
	DB	0			; step rate
Q2030:					; 16.
	DB	16			; sectors
	DW	511			; cylinders-1
	DB	5			; heads-1
	DB	020h			; sector size mask
	DB	0			; step rate
Q2040:					; 17.
	DB	16			; sectors
	DW	511			; cylinders-1
	DB	7			; heads-1
	DB	020h			; sector size mask
	DB	0			;  step rate
M2010:					; 18.
	DB	16			; sectors
	DW	479			; cylinders-1
	DB	1			; heads-1
	DB	020h			; sector size mask
	DB	0			; step rate
M2020:					; 19.
	DB	16			; sectors
	DW	479			; cylinders-1
	DB	3			; heads-1
	DB	020h			; sector size mask
	DB	0			; step rate
DMA5_5:					; 20.
	DB	33			; sectors
	DW	319			; cylinders-1
DMAHDS:	DB	3			; heads-1
	DB	000h			; sector size mask
	DB	00fh			; step rate (for this drv =0 dma prom, =f wd prom)

;----------
; MESSAGES
;----------

SIGNON:	DB	'FMTHD 2.4',CR,LF,LF
MENU:
	DB	'0.)  ST503             10.)  SA604		20.)  DMA 5/5',CR,LF
   	DB	'1.)  ST506             11.)  SA606',  CR,LF
	DB	'2.)  TM601S            12.)  SA1002', CR,LF
	DB	'3.)  TM602S            13.)  SA1004', CR,LF
	DB	'4.)  TM603S            14.)  Q2010',  CR,LF
	DB	'5.)  TM603SE           15.)  Q2020',  CR,LF
	DB	'6.)  TM501 or ST406    16.)  Q2030',  CR,LF
	DB	'7.)  TM502 or ST412    17.)  Q2040',  CR,LF
	DB	'8.)  TM503 or ST419    18.)  M4010',  CR,LF
	DB	'9.)  SA602             19.)  M4020',  CR,LF
	DB	LF
	DB	'Enter drive to format: $'              

CARMSG:	DB	CR,LF,'Format (C)artriage, (F)ixed, or (B)oth : $'
INVAL:	DB	CR,LF,'Invalid input try again.',CR,LF,'$'
DRVMSG:	DB	CR,LF,'Which physical hard disk do you want to format. (0-3)? $'
Q1:	DB	CR,LF,'This operation will destroy all data on drive $'
Q2:	DB	'.',CR,LF,'Hit return to continue or ^C to abort.$'
FORMSG:	DB	LF,'Formatting. CYLINDER     '
HDMSG:	DB	' HEAD $'
BSMSG:	DB	BS,BS,BS,BS,BS,BS,BS,BS,BS,BS,'$'
VERMSG1:DB	LF
VERMSG:	DB	CR,'Verifying.  CYLINDER      HEAD $'
ERRST:	DB	CR,LF,'HDC1001 Error $'
ERRHD:	DB	' on Head $'
ERRCYL:	DB	', Cylinder $'
ERRSEC:	DB	', Sector $'
DNEMSG:	DB	CR,LF,'Format completed.$'
URCMSG:	DB	'Sorry, unrecoverable error during format.$'
ABTMSG:	DB	CR,LF,'Operation aborted.$'

;-----------
; VARIABLES
;-----------

HDMSK:	DB	-1
RETRY:	DB	0			; Retry count
UNIT:	DS	1			; Physical device unit
INTERB:	DB	8			; Current interleave
SECS:	DS	1			; Sectors per track
CYLS:	DS	2			; Cylinders per drive
HEADS:	DS	1			; Heads per drive
SIZMSK:	DS	1			; Sector size mask
STPRTE:	DS	1			; Step rate 	
INTERº	DÓ	²			» 1¶ biô interleave
NSECS:	DS	2			; 16 bit negative SECS
LIMIT:	DS	2			; Upper memory limit of table
INBUF:	DB	64			; Line input buffer
NUMCHR:	DS	1			; Number of characters returned
INTTBL:	DS	64			; Interleave table
	END