; CTIME.INC  (Retro Unix 8086 v1 - /bin/ls - list file or directory)
; ----------------------------------------------------------------------------
;
; RETRO UNIX 8086 (Retro Unix == Turkish Rational Unix)
; Operating System Project (v0.1) by ERDOGAN TAN (Beginning: 11/07/2012) 
; Retro UNIX 8086 v1 - /bin/ls file
;
; [ Last Modification: 28/11/2013 ]
;
; Derivation from UNIX Operating System (v1.0 for PDP-11) 
; (Original) Source Code by Ken Thompson (Bell Laboratories, 1971-1972)
;
; ****************************************************************************
;
; Derived from 'ctime.c' file of original UNIX v5 (usr/source/s3/ctime.c)
;
; LS0.ASM, 19/11/2013 - 24/11/2013
; include ctime.inc
;
; ****************************************************************************

; .8086

;timezone equ 5*60*60


ctime:  ; ctime(at)
	; int *at;
	; {
	; 	return(asctime(localtime(at)));
	; }

	; DX:AX = unix epoch time (in seconds)

	;call localtime
	;call asctime

	;retn
  
localtime:
	; localtime(tim)
	; int tim[];
	; 	{
	;		register int *t, *ct, dayno;
	;	int daylbegin, daylend;
	;	int copyt[2];
	;	t = copyt;
	;	t[0] = tim[0];
	;	t[1] = tim[1];
	;	dpadd(t, -timezone);
	;	ct = gmtime(t);
	;	dayno = ct[YDAY];
	;	if (nixonflg && (ct[YEAR]>74 || ct[YEAR]==74 && (dayno > 5 ||
	;	    dayno==5 && ct[HOUR]>=2))) {
	;		daylight =| 1;
	;		daylbegin = -1;
	;		daylend = 367;
	;	} else {
	;		daylbegin = sunday(ct, 119);	/* last Sun in Apr */
	;		daylend = sunday(ct, 303);	/* last Sun in Oct */
	;	}
	;	if (daylight &&
	;	    (dayno>daylbegin || (dayno==daylbegin && ct[HOUR]>=2)) &&
	;	    (dayno<daylend || (dayno==daylend && ct[HOUR]<1))) {
	;		dpadd(t, 1*60*60);
	;		ct = gmtime(t);
	;		ct[ISDAY]++;
	;	}
	;	return(ct);
	;	}

	;sub	ax, timezone	
	;sbb	dx, 0
	
	;push	dx
	;push	ax

	call 	gmtime
; if (nixonflg && (ct[YEAR]>74 || ct[YEAR]==74 && (dayno > 5 ||
;     dayno==5 && ct[HOUR]>=2))) {
	;cmp	byte ptr [nixonflg], 0
	;jna	short lt1
	;cmp	word ptr [year], 1974
	;jb	short lt1
	;ja	short lt0
	;cmp	word ptr [yday], 5
	;jb	short lt1
	;ja	short lt0 
	;cmp	word ptr [hour], 2
	;jb	short lt1
; nixonflag > 0
;lt0:
	;mov	word ptr [daylight], 1
	;mov	word ptr [daylbegin], -1
	;mov	word ptr [daylend], 367
;	;jmp	short lt2

; } else {
;lt1:
;	mov	cx, 119
;	call	sunday ; sunday(ct, 119); /* last Sun in Apr */
;	mov	word ptr [daylbegin], cx
;	mov	cx, 303
;	call	sunday ; sunday(ct, 303); /* last Sun in Oct */	
;	mov	word ptr [daylend], cx
;lt2:
; if (daylight &&
;    (dayno>daylbegin || (dayno==daylbegin && ct[HOUR]>=2)) &&
;    (dayno<daylend || (dayno==daylend && ct[HOUR]<1))) {

;	pop	ax
;	pop	dx

	;cmp	byte ptr [daylight], 0
	;jna	short lt5
	
	;mov	cx, word ptr [yday]

	;cmp	cx, word ptr [daylbegin]
	;jb	short lt5
	;ja	short lt3
	;cmp	word ptr [hour], 2
	;jb	short lt5
	;jmp	short lt4
;lt3:
	;cmp	cx, word ptr [daylend]
	;jb	short lt4
	;ja	short lt5
	;cmp	word ptr [hour], 1
	;jnb	short lt5
;lt4:
	;add	ax, 1*60*60
	;adc	dx, 0
	;call	gmtime
	;inc	word ptr [isday]
;lt5:
;	}
;	return(ct);
;	}

	;retn


asctime:
	; asctime(t)
	;int *t;
	;{
	;	register char *cp, *ncp;
	;	register int *tp;
	;
	;	cp = cbuf;
	;	for (ncp = "Day Mon 00 00:00:00 1900\n"; *cp++ = *ncp++;);
	;	ncp = &"SunMonTueWedThuFriSat"[3*t[6]];
	;	cp = cbuf;
	;	*cp++ = *ncp++;
	;	*cp++ = *ncp++;
	;	*cp++ = *ncp++;
	;	cp++;
	;	tp = &t[4];
	;	ncp = &"JanFebMarAprMayJunJulAugSepOctNovDec"[(*tp)*3];
	;	*cp++ = *ncp++;
	;	*cp++ = *ncp++;
	;	*cp++ = *ncp++;
	;	cp = numb(cp, *--tp);
	;	cp = numb(cp, *--tp+100);
	;	cp = numb(cp, *--tp+100);
	;	cp = numb(cp, *--tp+100);
	;	cp =+ 2;
	;	cp = numb(cp, t[YEAR]);
	;	return(cbuf);
	;}
	
	;;mov	di, offset Cbuf
	;;mov	si, offset ncp0
	;;mov	cx, 13
	;;movsw	
	;
	mov	di, offset Cbuf	
	;mov	si, word ptr [wday]
	;shl	si, 1
	;shl	si, 1
	;add	si, offset ncp1
	;movsw
	;movsw
	mov	si, word ptr [month]
	shl	si, 1
	shl	si, 1
	add	si, offset ncp2 - 4
	movsw
	movsw
	mov	ax, word ptr [day]
	;mov	cx, 10
	mov	cl, 10
	call	numb
 	mov	al, 20h
	stosb
	;
	mov	ax, word ptr [year]
	mov	ch, 100
	div	ch
	push	ax ;
	cbw ; century (19, 20)
	call	numb
	pop	ax
	mov	al, ah
	cbw ;	year (0 to 99)
	call	numb
	mov 	al, 20h
	stosb
	;
	mov	si, word ptr [wday]
	shl	si, 1
	shl	si, 1
	add	si, offset ncp1
	movsw
	movsw
	;
	mov	ax, word ptr [hour]
	call	numb
 	mov	al, ':'
	stosb
	mov	ax, word ptr [minute]
	call	numb
 	mov	al, ':'
	stosb
	mov	ax, word ptr [second]
	call	numb
 	mov	al, 20h
	stosb
	;mov	ax, word ptr [year]
	;mov	ch, 100
	;div	ch
	;push	ax ;
	;cbw ; century (19, 20)
	;call	numb
	;pop	ax
	;mov	al, ah
	;cbw ;	year (0 to 99)
	;call	numb
	;mov	al, 20h
	;stosb
	;xor	al, al
	;stosb

	retn

gmtime:
	; 24/11/2013 (yday, wday)
	; Retro UNIX 8086 v1 - UNIX.ASM (20/06/2013)
	; Retro UNIX 8086 v1 feature/procedure only!
	; 'convert_from_epoch' procedure prototype: 
	; 	            UNIXCOPY.ASM, 10/03/2013
	; 30/11/2012
	; Derived from DALLAS Semiconductor
	; Application Note 31 (DS1602/DS1603)
	; 6 May 1998
	;
	; INPUT:
	; DX:AX = Unix (Epoch) Time
	;
	; ((Modified registers: AX, DX, CX, BX))  
	;
	mov cx, 60
	call div32
	;mov word ptr [imin], ax   ; whole minutes
	;mov word ptr [imin]+2, dx ; since 1/1/1970
	mov word ptr [second], bx  ; leftover seconds
	; mov cx, 60
	call div32
	;mov word ptr [ihrs], ax   ; whole hours
	;mov word ptr [ihrs]+2, dx ; since 1/1/1970
	mov word ptr [minute], bx  ; leftover minutes
	; mov cx, 24
	mov cl, 24
	call div32
	;mov word ptr [iday], ax  ; whole days
				  ; since 1/1/1970
	mov word ptr [wday], ax ; 24/11/2013	
	; mov word ptr [iday]+2, dx ; DX = 0
	mov word ptr [hour], bx   ; leftover hours
	add ax, 365+366		  ; whole day since
				  ; 1/1/1968 	
	; adc dx, 0	          ;  DX = 0
	; mov word ptr [iday], ax
	push ax
	mov cx, (4*365)+1	  ; 4 years = 1461 days
	call div32
	pop cx
	;mov word ptr [lday], ax  ; count of quadyrs (4 years)
	push bx
	;mov word ptr [qday], bx  ;  days since quadyr began
	cmp bx, 31 + 29           ; if past feb 29 then
	cmc			  ; add this quadyr's leap day
	adc ax, 0		  ; to # of qadyrs (leap days)
	;mov word ptr [lday], ax  ; since 1968			  
	;mov cx, word ptr [iday]
	xchg cx, ax		  ; CX = lday, AX = iday		  
	sub ax, cx		  ; iday - lday
	mov cx, 365
	;xor dx, dx		  ; DX  = 0
	; AX = iday-lday, DX = 0
	call div32
	;mov word ptr [iyrs], ax   ; whole years since 1968
	; jday = iday - (iyrs*365) - lday
	;mov word ptr [jday], bx  ; days since 1/1 of current year
	add ax, 1968		  ; compute year
	mov word ptr [year], ax
	mov dx, ax		
	;mov ax, word ptr [qday]
	pop ax
	cmp ax, 365		  ; if qday <= 365 and qday >= 60	
	ja short @f		  ; jday = jday +1
	cmp ax, 60	          ; if past 2/29 and leap year then
        cmc			  ; add a leap day to the # of whole
	adc bx, 0		  ; days since 1/1 of current year
@@:			
	; mov word ptr [jday], bx
	;mov word ptr [yday], bx ; 24/11/2013	
	mov cx, 12		  ; estimate month
	xchg cx, bx		  ; CX = jday, BX = month 	
	mov ax, 366		  ; mday, max. days since 1/1 is 365
	and dx, 11b		  ; year mod 4	(and dx, 3) 
@@:	; Month calculation	  ; 0 to 11  (11 to 0)	
	cmp cx, ax		  ; mday = # of days passed from 1/1
	jnb short @f
	dec bx			  ; month = month - 1
	shl bx, 1 
	mov ax, word ptr DMonth[BX] ; # elapsed days at 1st of month
	shr bx, 1		  ; bx = month - 1 (0 to 11)
	cmp bx, 1		  ; if month > 2 and year mod 4  = 0	
	jna short @b		  ; then mday = mday + 1
	or dl, dl		  ; if past 2/29 and leap year then
	jnz short @b		  ; add leap day (to mday)
	inc ax			  ; mday = mday + 1
	jmp short @b
@@:
	inc bx 			  ; -> bx = month, 1 to 12
	mov word ptr [month], bx
	sub cx, ax		  ; day = jday - mday + 1	
	inc cx 			  
	mov word ptr [day], cx
	
	; ax, bx, cx, dx is changed at return
	; output ->
	; [year], [month], [day], [hour], [minute], [second]
	; [yday] -> 24/11/2013
	; [wday] -> 24/11/2013
	;
	; 24/11/2013
	mov	ax, word ptr [wday] ; [iday]
	xor	dl, dl ; xor dx, dx
	; dx = 0	
	add	ax, 4
	; NOTE: January 1, 1970 was THURSDAY
	; ch = 0
	mov	cl, 7
	div	cx
	mov	word ptr [wday], dx ; week of the day,  0 to 6 
	; 0 = sunday ... 6 = saturday
	;mov	word ptr [isday], 0

	retn

div32:
	; Input -> DX:AX = 32 bit dividend
	;          CX = 16 bit divisor
	; output -> DX:AX = 32 bit quotient
	;          BX = 16 bit remainder
	mov  bx, dx
	xchg ax, bx
	xor  dx, dx
	div  cx         ; at first, divide DX
	xchg ax, bx     ; remainder is in DX
			; now, BX has quotient
			; save remainder
	div  cx         ; so, DX_AX divided and
			; AX has quotient
			; DX has remainder
	xchg dx, bx     ; finally, BX has remainder

	retn

;sunday:
	; sunday(at, ad)
	; 	int *at;
	;	 {
	; 	register int *t, d;
	; 	t = at;
	; 	d = ad;
	; 	d = ad + dysize(t[YEAR]) - 365;
	; 	return(d - (d - t[YDAY] + t[WDAY] + 700) % 7);
	; 	}

	;mov	dx, word ptr [year]
	;call	dysize
	;sub	ax, 365
	; add 	cx, ax
;	test	word ptr [year], 11b
;	jnz	short @f
	; CX = 119 (77h) or CX = 303 (12Fh)
	;inc	cx
;	inc	cl
;@@:
;	mov	ax, cx
;	add	ax, word ptr [wday]
	;adc	ax, 700
;	add	ax, 700
;	sub	ax, word ptr [yday]
	;xor	dx, dx
;	mov	bx, 7
	;div	bx
;	div	bl
;	sub	cx, bx
;	retn

;dysize:
; dysize(y)
;	{
;	if((y%4) == 0)
;		return(366);
;	return(365);
;	}

;	mov 	ax, 365	
;	test 	dx, 11b
;	jnz 	short @f
;	;inc 	ax
	inc 	al			
;@@:	
;	retn 
		

numb:   ; AX = 0 to 99
	;
	; numb(acp, n)
	; {
	;	register char *cp;
	;
	;	cp = acp;
	;	cp++;
	;	if (n>=10)
	;	   *cp++ = (n/10)%10 + '0';
	;	else
	;	   *cp++ = ' ';
	;	*cp++ = n%10 + '0';
	;	return(cp);
	; }
	;
	;mov	cl, 10
	cmp 	ax, 10
	jnb	short nb1
	mov	ah, al
	xor	al, al ; 0
	jmp	short nb2
nb1:	
	div	cl
	mov	dl, ah
	
nb2:	
	add	al, '0'
	stosb	; digit 1
	mov	al, ah
	add	al, '0'
	stosb	; digit 2
	retn


;;; DATA

;daylight: db 1 ; int daylight 1; /* Allow daylight conversion */
;nixonflg: db 0 ; int nixonflg 0; /* Daylight time all year around */
;daylbegin: dw 0
;daylend: dw 0


ct:
; 24/11/2013 (re-order)
;
; Retro UNIX 8086 v1 - UNIX.ASM
; 09/04/2013 epoch variables
; Retro UNIX 8086 v1 Prototype: UNIXCOPY.ASM, 10/03/2013
;

second: dw 0
minute: dw 0
hour: dw 0
day: dw 1
month: dw 1
year: dw 1970
wday: dw 0 ; 24/11/2013
;yday: dw 0 ; 24/11/2013
;isday: dw 0 ; 24/11/2013

DMonth:
dw 0
dw 31
dw 59
dw 90
dw 120
dw 151
dw 181
dw 212
dw 243
dw 273
dw 304
dw 334

;ncp0: db "Day Mon 00 00:00:00 1970", 0, 0
ncp1: db "Sun Mon Tue Wed Thu Fri Sat "
ncp2: db "Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec "

cbuf: 	; char cbuf[26]
	db 26 dup(0)

COMMENT @
;; ctime.c (Unix v5)

#
/*
 * This routine converts time as follows.
 * The epoch is 0000 Jan 1 1970 GMT.
 * The argument time is in seconds since then.
 * The localtime(t) entry returns a pointer to an array
 * containing
 *  seconds (0-59)
 *  minutes (0-59)
 *  hours (0-23)
 *  day of month (1-31)
 *  month (0-11)
 *  year-1970
 *  weekday (0-6, Sun is 0)
 *  day of the year
 *  daylight savings flag
 *
 * The routine corrects for daylight saving
 * time and will work in any time zone provided
 * "timezone" is adjusted to the difference between
 * Greenwich and local standard time (measured in seconds).
 * In places like Michigan "daylight" must
 * be initialized to 0 to prevent the conversion
 * to daylight time.
 *
 * "nixonflg,", if set to 1, will
 * cause daylight savings time all year around
 * independently of "daylight".
 *
 * The routine does not work
 * in Saudi Arabia which runs on Solar time.
 *
 * asctime(tvec))
 * where tvec is produced by localtime
 * returns a ptr to a character string
 * that has the ascii time in the form
 *	Thu Jan 01 00:00:00 1970n0\\
 *	01234567890123456789012345
 *	0	  1	    2
 *
 * ctime(t) just calls localtime, then asctime.
 */
char	cbuf[26];
int	dmsize[12]
{
	31,
	28,
	31,
	30,
	31,
	30,
	31,
	31,
	30,
	31,
	30,
	31
};

int timezone	5*60*60;
int tzname[]
{
	"EST",
	"EDT",
};
int	daylight 1;	/* Allow daylight conversion */
int	nixonflg 0;	/* Daylight time all year around */

#define	SEC	0
#define	MIN	1
#define	HOUR	2
#define	MDAY	3
#define	MON	4
#define	YEAR	5
#define	WDAY	6
#define	YDAY	7
#define	ISDAY	8

ctime(at)
int *at;
{
	return(asctime(localtime(at)));
}

localtime(tim)
int tim[];
{
	register int *t, *ct, dayno;
	int daylbegin, daylend;
	int copyt[2];

	t = copyt;
	t[0] = tim[0];
	t[1] = tim[1];
	dpadd(t, -timezone);
	ct = gmtime(t);
	dayno = ct[YDAY];
	if (nixonflg && (ct[YEAR]>74 || ct[YEAR]==74 && (dayno > 5 ||
	    dayno==5 && ct[HOUR]>=2))) {
		daylight =| 1;
		daylbegin = -1;
		daylend = 367;
	} else {
		daylbegin = sunday(ct, 119);	/* last Sun in Apr */
		daylend = sunday(ct, 303);	/* last Sun in Oct */
	}
	if (daylight &&
	    (dayno>daylbegin || (dayno==daylbegin && ct[HOUR]>=2)) &&
	    (dayno<daylend || (dayno==daylend && ct[HOUR]<1))) {
		dpadd(t, 1*60*60);
		ct = gmtime(t);
		ct[ISDAY]++;
	}
	return(ct);
}

sunday(at, ad)
int *at;
{
	register int *t, d;

	t = at;
	d = ad;
	d = ad + dysize(t[YEAR]) - 365;
	return(d - (d - t[YDAY] + t[WDAY] + 700) % 7);
}

gmtime(tim)
int tim[];
{
	register int d0, d1;
	register *tp;
	static xtime[9];
	extern int ldivr;

	/*
	 * break initial number into
	 * multiples of 8 hours.
	 * (28800 = 60*60*8)
	 */

	d0 = ldiv(tim[0], tim[1], 28800);
	d1 = ldivr;
	tp = &xtime[0];

	/*
	 * generate hours:minutes:seconds
	 */

	*tp++ = d1%60;
	d1 =/ 60;
	*tp++ = d1%60;
	d1 =/ 60;
	d1 =+ (d0%3)*8;
	d0 =/ 3;
	*tp++ = d1;

	/*
	 * d0 is the day number.
	 * generate day of the week.
	 */

	xtime[WDAY] = (d0+4)%7;

	/*
	 * year number
	 */
	for(d1=70; d0 >= dysize(d1); d1++)
		d0 =- dysize(d1);
	xtime[YEAR] = d1;
	xtime[YDAY] = d0;

	/*
	 * generate month
	 */

	if (dysize(d1)==366)
		dmsize[1] = 29;
	for(d1=0; d0 >= dmsize[d1]; d1++)
		d0 =- dmsize[d1];
	dmsize[1] = 28;
	*tp++ = d0+1;
	*tp++ = d1;
	xtime[ISDAY] = 0;
	return(xtime);
}

asctime(t)
int *t;
{
	register char *cp, *ncp;
	register int *tp;

	cp = cbuf;
	for (ncp = "Day Mon 00 00:00:00 1900\n"; *cp++ = *ncp++;);
	ncp = &"SunMonTueWedThuFriSat"[3*t[6]];
	cp = cbuf;
	*cp++ = *ncp++;
	*cp++ = *ncp++;
	*cp++ = *ncp++;
	cp++;
	tp = &t[4];
	ncp = &"JanFebMarAprMayJunJulAugSepOctNovDec"[(*tp)*3];
	*cp++ = *ncp++;
	*cp++ = *ncp++;
	*cp++ = *ncp++;
	cp = numb(cp, *--tp);
	cp = numb(cp, *--tp+100);
	cp = numb(cp, *--tp+100);
	cp = numb(cp, *--tp+100);
	cp =+ 2;
	cp = numb(cp, t[YEAR]);
	return(cbuf);
}

dysize(y)
{
	if((y%4) == 0)
		return(366);
	return(365);
}


numb:
	

numb(acp, n)
{
	register char *cp;

	cp = acp;
	cp++;
	if (n>=10)
		*cp++ = (n/10)%10 + '0';
	else
		*cp++ = ' ';
	*cp++ = n%10 + '0';
	return(cp);
}

@
