#include 9sequate.asm		
	#include 9sfunc.h
	#include 9srva.h
;=========================================================================
;Sets up baudrates and control registers and receives data input from user
;=========================================================================
	org 	RAM
	lds 	#STACK
	movb 	#$01,$d0	;Baudrate register high
	movb 	#$38,$d1	; baudrate low
	movb 	#$e4,$d2    ; d2 Sets control register - see pg 15 - 17 of lab book for reasoning
	movb 	#$ec,$d3	; d3 for CR 2

get	ldx	getchar		; Stores the address of the getchar function in x
	jsr	0,x		; indirect addressing to starts the getchar function
	ldx	putchar		; displays the character I just input to the screen
	jsr	0,x		; now character I input is in Acc B.
	
;=========================================================================
;ensures our data input is valid (from 0-9)
;=========================================================================
	cmpb	#$2f		; (too low)
	ble	bad		; Branch to dead loop if we're outside our range
	cmpb	#$3a		; (too high)
	bge	bad		; If not in our range, branch to invalid character loop
	bra	tran


bad	ldd	#strb		; Loads our string for printf with what we want
	ldx	printf		; indirect addressing for printf command
	jsr	0,x
	leas	2,sp		; clean printf parameter off stack
	bra	get		; back 

strb	fcc	" Character out of range " 	; intend for kermit0
	db	$d,$a,0			; cr, lf and terminator


;========================================================================
;To be used to transmit to smart mode gps
;========================================================================
tran	subb	#$30		; subtract $30, converts from ascii to hex
	movb 	#$02,$d5		;set Tx direction to output
	brclr 	$d4,#$80,*	; poll TDRE to let us input data
	movb 	#$21,$d7		;! into DRL
	brclr 	$d4,#$80,*	;poll TDRE until DRL is empty
	movb 	#$47,$d7		;G into DRL
	brclr 	$d4,#$80,*
	movb 	#$50,$d7		;P into DRL
	brclr 	$d4,#$80,*
	movb 	#$53,$d7		;S into DRL
	brclr	$d4,#$80,*
	stab	$d7	
	
;=========================================================================
;sets program up for receiving data
;=========================================================================

	brclr $d4,#$40,*	;polls until transmission complete
	movb #$00,$d5		;set Tx direction to input

;=========================================================================
;Selects which program we want to use for displaying the received information
;=========================================================================

	cmpb	#$00		; input = 0
	bgt	sk0		; skip code for gps type display

;=========================
;gps type (2 bytes)
;=========================

	brclr 	$d4,#$20,*	; poll until data register is full (ie, entire byte received)
				; when full, d4 bit 5 flag goes up 
	ldaa 	$d7		; loads data from data input register to accumulator b
	ldaa	#$00
	brclr	$d4,#$20,*	; slight error, ! is displayed unless I discard the first byte
	ldab	$d7		; overwrite the ! with the new data	
	pshd
	brclr	$d4,#$20,*
	ldab	$d7
	pshd
	ldd	#str0
	ldx 	printf
	jsr 	0,x
	leas	2,sp
b0	lbra	get

str0	fcc	" %2u (hardware): %2u (firmware) GPS type " 
	db	$d,$a,0

sk0	cmpb	#$01		; input = 1
	bgt	sk1		; skip code for valid data string

;=========================
;validity of data string (1 byte)
;=========================
	brclr 	$d4,#$20,*	; poll until data register is full (ie, entire byte received)
				; when full, d4 bit 5 flag goes up 
	ldaa 	$d7		; loads data from data input register to accumulator b
	brclr	$d4,#$20,*	; slight error, ! is displayed unless I discard the first byte
	ldab	$d7		; overwrite the ! with the new data
	cmpb	#$00
	ble	no
	ldd	#str1
	ldx 	printf
	jsr 	0,x
	leas	2,sp
b1	lbra	b0

str1	fcc	" Valid Data " 
	db	$d,$a,0

no	ldd	#str1n
	ldx 	printf
	jsr 	0,x
	leas	2,sp
	bra	b1

str1n	fcc	" Invalid Data " 
	db	$d,$a,0

sk1	cmpb	#$02		; input = 2
	bgt	sk2		; bypass code for number of satellites

;=========================
;number of satellites (1 byte)
;=========================
	brclr 	$d4,#$20,*	; poll until data register is full (ie, entire byte received)
				; when full, d4 bit 5 flag goes up 
	ldaa 	$d7		; loads data from data input register to accumulator b
	brclr	$d4,#$20,*	; slight error, ! is displayed unless I discard the first byte
	ldab	$d7		; overwrite the ! with the new data
	ldaa	#$00		; load Acc A with 0's so printf command only reads the	
	pshd			; significant data
	ldd	#str2
	ldx 	printf
	jsr 	0,x
	leas	2,sp
b2	lbra	b1

str2	fcc	" %u Satellites acquired " 
	db	$d,$a,0


sk2	cmpb	#$03		; input = 3
	bgt	sk3		; bypass code for time

;=========================
;time (3 bytes)
;=========================	
	brclr 	$d4,#$20,*	; poll until data register is full (ie, entire byte received)
				; when full, d4 bit 5 flag goes up 
	ldaa 	$d7		; loads data from data input register to accumulator b
	brclr	$d4,#$20,*	; slight error, ! is displayed unless I discard the first byte
	ldaa	#$00		; overwrite the ! with 0's in accumulator A
		
;printf command accesses 2 bytes from the stack, whereas the information sent from the 
;chip is 3 individual bytes, not intended to be combined together. We want to access just the 
;desired byte (we put it into Acc. B) and not combine it with anything fromm Acc. A.
;
	brclr	$d4,#$20,*
	movb	$d7,hrs		; load data from received data registed into Acc B.
	brclr	$d4,#$20,*
	movb	$d7,min
	brclr	$d4,#$20,*
	ldab	$d7
	pshd	
	ldab	min
	pshd
	ldab	hrs
	pshd
	ldd	#str3
	ldx	printf
	jsr	0,x
	leas	6,sp
b3	lbra	b2

str3	fcc	" The current atomic time is %.2u:%.2u:%.2u GMT " 
	db	$d,$a,0

hrs	rmb	1
min	rmb	1

sk3	cmpb	#$04		; input = 4
	bgt	sk4		; bypass code for date

;=========================
;date (3 bytes)
;=========================	
	brclr 	$d4,#$20,*	; poll until data register is full (ie, entire byte received)
				; when full, d4 bit 5 flag goes up 
	ldaa 	$d7		; loads data from data input register to accumulator b
	brclr	$d4,#$20,*	; slight error, ! is displayed unless I discard the first byte
	ldaa	#$00		; overwrite the ! with 0's in accumulator A
		
;printf command accesses 2 bytes from the stack, whereas the information sent from the 
;chip is 3 individual bytes, not intended to be combined together. We want to access just the 
;desired byte (we put it into Acc. B) and not combine it with anything fromm Acc. A.
;
	brclr	$d4,#$20,*
	movb	$d7,mon		; load data from received data registed into Acc B.
	brclr	$d4,#$20,*
	movb	$d7,day
	brclr	$d4,#$20,*
	ldab	$d7
	pshd	
	ldab	day
	pshd
	ldab	mon
	pshd
	ldd	#str4
	ldx	printf
	jsr	0,x
	leas	6,sp
b4	lbra	b3

str4	fcc	" Today's date is %.2u/%.2u/20%.2u (Day/Month/Year) " 
	db	$d,$a,0

mon	rmb	1
day	rmb	1

sk4	cmpb	#$05		; input = 5
	bgt	sk5		; skip code for latitude display
;=========================================================================
;Latitude (5 bytes)
;=========================================================================

	brclr 	$d4,#$20,*	; poll until data register is full (ie, entire byte received)
				; when full, d4 bit 5 flag goes up 
	ldaa 	$d7		; loads data from data input register to accumulator b
	brclr	$d4,#$20,*	; slight error, ! is displayed unless I discard the first byte
	ldaa	#$00		; overwrite the ! with the new data		
	brclr	$d4,#$20,*
	ldab	$d7
	stab	deg
	brclr	$d4,#$20,*
	ldab	$d7
	stab	mint
	brclr	$d4,#$20,*
	ldaa	$d7
	brclr	$d4,#$20,*
	ldab	$d7
	std	fm
	brclr	$d4,#$20,*
	ldaa	#$00
	ldab	$d7
	cmpb	#$00
	ble	north
	ldab	#$53
	bra	lat
north	ldab	#$4e	
lat	pshd
	ldd	fm
	pshd
	ldaa	#$00
	ldab	mint
	pshd
	ldab	deg
	pshd
	ldd	#str5
	ldx 	printf
	jsr 	0,x
b5	lbra	b4

str5	fcc	" Latitude %u* %u.%04u' %c " 
	db	$d,$a,0

deg	rmb	1
mint	rmb	1
fm	rmb	2


sk5	cmpb	#$06		; input = 6
	bgt	sk6		; skip code for longitude display
;=========================================================================
; Longitude (5 bytes)
;=========================================================================

	brclr 	$d4,#$20,*	; poll until data register is full (ie, entire byte received)
				; when full, d4 bit 5 flag goes up 
	ldaa 	$d7		; loads data from data input register to accumulator b
	brclr	$d4,#$20,*	; slight error, ! is displayed unless I discard the first byte
	ldaa	#$00		; overwrite the ! with the new data		
	brclr	$d4,#$20,*
	ldab	$d7
	stab	deg2
	brclr	$d4,#$20,*
	ldab	$d7
	stab	min2
	brclr	$d4,#$20,*
	ldaa	$d7
	brclr	$d4,#$20,*
	ldab	$d7
	std	fm2
	brclr	$d4,#$20,*
	ldaa	#$00
	ldab	$d7
	cmpb	#$00
	ble	east
	ldab	#$57
	bra	dis
east	ldab	#$45	
dis	pshd
	ldd	fm2
	pshd
	ldaa	#$00
	ldab	min2
	pshd
	ldab	deg2
	pshd
	ldd	#str6
	ldx 	printf
	jsr 	0,x
b6	lbra	b5

str6	fcc	" Longitude %u* %u.%04u' %c " 
	db	$d,$a,0

deg2	rmb	1
min2	rmb	1
fm2	rmb	2

sk6	cmpb	#$07		; input = 7
	bgt	sk7		; skip code for altitude display

;=========================
;altitude (2 bytes)
;=========================

balt	brclr 	$d4,#$20,*	; poll until data register is full (ie, entire byte received)
				; when full, d4 bit 5 flag goes up 
	ldaa 	$d7		; loads data from data input register to accumulator b
	brclr	$d4,#$20,*	; slight error, ! is displayed unless I discard the first byte
	ldaa	$d7		; overwrite the ! with the new data		
	brclr	$d4,#$20,*
	ldab	$d7
	pshd
	ldd	#str7
	ldx 	printf
	jsr 	0,x
	leas	2,sp
b7	lbra	b6

str7	fcc	" Current altitude %u E-1 m " 
	db	$d,$a,0


sk7	cmpb	#$08		; input = 8
	bgt	sk8		; send to code for velocity display

;=========================
;velocity (2 bytes)
;=========================

	brclr 	$d4,#$20,*	; poll until data register is full (ie, entire byte received)
				; when full, d4 bit 5 flag goes up 
	ldaa 	$d7		; loads data from data input register to accumulator b
	brclr	$d4,#$20,*	; slight error, ! is displayed unless I discard the first byte
	ldaa	$d7		; overwrite the ! with the new data		
	brclr	$d4,#$20,*
	ldab	$d7
	pshd
	ldd	#str8
	ldx 	printf
	jsr 	0,x
	leas	2,sp
b8	lbra	b7

str8	fcc	" Current speed is %u E-1 knots " 
	db	$d,$a,0


; if none of the above, codes for heading	

;=========================
;Heading (2 bytes)
;=========================

sk8	brclr 	$d4,#$20,*	; poll until data register is full (ie, entire byte received)
				; when full, d4 bit 5 flag goes up 
	ldaa 	$d7		; loads data from data input register to accumulator b
	brclr	$d4,#$20,*	; slight error, ! is displayed unless I discard the first byte
	ldaa	$d7		; overwrite the ! with the new data		
	brclr	$d4,#$20,*
	ldab	$d7
	pshd
	ldd	#str9
	ldx 	printf
	jsr 	0,x
	leas	2,sp
	bra	b8

str9	fcc	" %u E-1 degrees (heading) " 
	db	$d,$a,0