page 60,132
MASM
; This is a modification of the programme described below (SNIPPER).
; 0.0.1	gets all chars on lines between point 1 and point 2
; 0.0.2	allows the use of HOME and END keys to move around the screen.
; 0.0.3	allows hitting ESC key in filename prompt for entering
;	completely new file name.
; 0.0.4	fixed bug in ESC key during filename entry.  If esc hit and
;	then return, will exit without saving to file.  if ESC hit
;	then chars entered for new filename, will print to file. 
; 0.0.5	added new option when writing to file.  Entering F will now
;	strip out all multiple spaces and any pipes, as well as will
;	put 2 spaces after any punctuation.  Old write to file
;	(unformatted) is now option "U"
; 0.0.6	fixed problem with help box not displaying all options and
;	correctly formatting the box.
; 0.0.7	fixed help box display so that it is uses it's own character 
;	attributes, and restores original attribute upon exit.
; 0.0.8	Added colour to Help Box.  Unsure if will work with mono
; 0.0.9	gets filename from first 8 chars or from first char to period, 
;	of first line of highlight, + .RTT.   Refuses all chars which
;	filenames can not contain.
; 0.1.0	checks for mono display adapter.  if present, displays mono
;	help.
; 0.1.1	Modified display of copyright notice.
; 0.1.2 Added use of INS key when moving to top_left position.  Hitting
;	INS will move the cursor to the 34th column, which is the
;	standard starting space for file descriptions on PCB/ProDoor BBSs
; 0.1.3	Fixed problem with getting filename, and hitting ESC.  Now
;	resets filechar flag so that if used again after hitting esc, 
;	or entering a new filename, will now find new filename.  
;	Also, fills out full space for filename with 0H after each
;	filename.  Previously, if the new filename was shorter than
;	the last one entered, there would be residual chars.
; 0.1.4	Fixed problem with underscore as part of a filename.  Had
;	accidently included it in the list of chars not acceptable.
; 0.1.5	Fixed highlighting problem associated with reading filenames
;	of 8 chars + ext.
; 0.1.6	Program sends "fl filename.ext" to keyboard buffer, for file 
;	flagging on BBS.
; 0.1.7 Pruned program of unused or unnecessary functions relating to
;	SNIPPER
; 0.1.8	Extended total filename size to a maximum of 50 chars for
;	large paths.
; 0.1.9	Fixed problem with using the program multiple
;	times.  Wouldn't write more than one file nor would it spit
;	out more then "F" on the second use in the file flag section.
; 0.2.0	Reduced Maximum filename length to 12 places in anticipation of
;	the use of a path statement on the command line to be added in
;	an upcomming version.
; 0.2.1	Added use of pathname on command line.  Path statement will 
;	now be /P=path.  Command line must be eithe filesnip by itself
;	or filesnip rows,cols,/P=path
; 0.3.0	No modifications - Found no bugs
; 0.4.0	No modifications - Found no bugs
; 0.5.0	No modifications - Found no bugs
; 0.6.0	No modifications - Found no bugs
; 0.7.0	No modifications - Found no bugs
; 0.8.0	No modifications - Found no bugs
; 0.9.0	No modifications - Found no bugs
; 1.0.0	Initial Release - 6 June 1990
; 1.0.1 Made use of path statement flag on command line non-case
;	sensitive.


; SNIPPER is a resident utility which allows cutting out a portion
; of the screen.  The selected portion may be printed, written
; to disk or entered in the keyboard buffer.  Activate SNIPPER by
; pressing CTL-~, then position the cursor in the upper left corner of
; the window using the arrow keys.  Press CR to fix the first corner,
; then expand the window with arrow keys.  Finally, type "P" to print,
; "F" for disk file, "G" to retrieve or CR for a help menu.  Press ESC
; any time to exit SNIPPER.  When installing SNIPPER, use the optional
; parameters to expand it's internal buffer for displays (such as the
; EGA) containing more than the standard 25 rows and 80 columns.
;   SNIPPER  [rows,columns]

;------------------------------------;
; BIOS_SEG IS THE ROM-BIOS DATA AREA ;
;------------------------------------;
BIOS_SEG	SEGMENT	AT 0040H
		ORG	004AH
CRT_COLS	DB	?		;CURRENT NUMBER OF COLUMNS
		ORG	0050H
CURSOR_POSN	DW	8 DUP(?)	;CURRENT CURSOR LOCATION
		ORG	0062H
ACTIVE_PAGE	DB	?		;ACTIVE PAGE FOR CGA AND EGA
		ORG	0084H
ROWS		DB	?		;LAST ROW NUMBER FOR EGA
BIOS_SEG	ENDS

CSEG		SEGMENT
		ASSUME	CS:CSEG,DS:NOTHING
		ORG	0100H		;BEGINNING FOR .COM PROGRAMS
START:		
                JMP	INITIALIZE	;INITIALIZATION CODE IS AT END
;--------------------------------;
; DATA AREA USED BY THIS PROGRAM ;
;--------------------------------;
HOTKEY		EQU	29H		;SCAN CODE FOR "~" KEY
SHIFT_MASK	EQU	00000100B	;MASK FOR CTL KEY
COPYRIGHT 	DB 	17 DUP(20H),214,44 DUP(196),183
		DB	13,10,17 DUP(20H),186,44 DUP(20H),186     
		DB	10,13,17 DUP(20H),186," File-SNIP 1.0.1 (c) 1990 Mad Monk Software ",186
		DB	10,13,17 DUP(20H),186,44 DUP(20H),186     
		DB	10,13,17 DUP(20H),186,44 DUP(20H),186     
		DB	10,13,17 DUP(20H),186,7,14 DUP(20H),"Hotkey is CTL-~",7,15 DUP(20H),186
		DB	10,13,17 DUP(20H),186,44 DUP(20H),186     
		DB 	10,13,17 DUP(20H),211,44 DUP(196),189,13,10,"$",1AH     
PROGRAMMER	DB	"File-SNIP:  Scott Penrose.  SNIPPER:  Tom Kihlken"
INSTALLED_MSG	DB	"Already Installed",13,10,"$"
BAD_DOS_MSG	DB	"Requires DOS 2.0+",13,10,"$"
OLDINT09	DD	?	;OLD KEYBOARD BREAK INTERRUPT VECTOR
OLDINT13	DD	?	;OLD BIOS DISK IO INTERRUPT VECTOR
OLDINT16	DD	?	;OLD KEYBOARD INTERRUPT VECTOR
OLDINT21	DD	?	;OLD DOS FUNCTION INTERRUPT VECTOR
ERR_STAT	DB	?	;ERROR STATUS DURING FILE OUTPUT
PATH_N_FILE	DB	128 DUP (0)
FILE_PATH	DB	114 DUP (0)
FILE_PROMPT	DB	"Enter Filename: "
FILENAME	DB	"FILESNIP.RTT"	;THE DEFAULT FILENAME
		DB	2 DUP (0)	;LEAVE ROOM FOR DRIVE AND PATH
BUFF_START	EQU	OFFSET INITIALIZE
BUFF_NEXT	DW  	BUFF_START	;POINTER TO NEXT KEY IN BUFFER
BUFF_LAST	DW  	BUFF_START	;POINTER TO LAST KEY IN BUFFER
BUFF_SIZE	EQU	25*(80+2)	;ROOM FOR 25 ROWS OF 80 COLUMNS
BUFF_END	DW	BUFF_START+BUFF_SIZE
FILE_BUFF_START	EQU	OFFSET INITIALIZE+BUFF_SIZE
FILE_BUFF_NEXT	DW  	FILE_BUFF_START	;POINTER TO NEXT KEY IN BUFFER
FILE_BUFF_LAST	DW  	FILE_BUFF_START	;POINTER TO LAST KEY IN BUFFER
FILE_BUFF_SIZE	EQU	12H  		;18 bytes
FILE_BUFF_END	DW	FILE_BUFF_START+FILE_BUFF_SIZE
TOP_LEFT	LABEL	WORD		;FIRST CORNER OF WINDOW
LEFT_SIDE	DB	0		;COLUMN NUMBER OF LEFT SIDE
TOP_ROW		DB	0		;ROW NUMBER OF TOP SIDE
BOT_RIGHT	LABEL	WORD		;SECOND CORNER OF WINDOW
RIGHT_SIDE	DB	?		;COLUMN NUMBER OR RIGHT SIDE
BOT_ROW		DB	?		;ROW NUMBER OF BOTTOM
SEND_CHAR	DW	?		;POINTER TO CHARACTER HANDLER
FILE_SEND_CHAR	DW	?		;POINTER TO CHARACTER HANDLER
HOME_END_HIT	LABEL	WORD		;if=1 then home was hit
HOME_END_LOOP	DB	0		;IF=1, then first time in loop
SEND_KEYS	DB	0		;IF=1, USE KEYSTROKES FROM BUFFER
FILE_SEND_KEYS	DB	0		;IF=1, USE KEYSTROKES FROM BUFFER
WRIT_FILE	DB	0		;IF=1, NEED TO WRITE TO DISK
BUSY_FLAGS	DB	0		;BIT MASKED AS FOLLOWS:
					; 1 - DOS IS ACTIVE
					; 2 - BIOS IO IS ACTIVE
					; 4 - SNIPPER IS ACTIVE
DOS_STAT	DB	0		;CURRENT DOS FUNCTION
SPACE_FLAG	DB	0		;Determine if space should be printed
FILECHAR	DB	0		;
FILE_EXT	DB	0
CHARS_ON_STACK	DB	0		;How many chars have been printed
PUNCT_FLAG 	DB	0		;was any punctuation found?
HELP_MENU	DB	201,21 DUP(205),187
		DB	186,"  F - File Formatted ",186
		DB	186,"  P - Print          ",186
		DB	186," Esc- Quit           ",186
		DB	200,21 DUP(205),188
HELP_MENU_ATTR1	DB	23 DUP(4EH)	;ANSI menu
		DB	23 DUP(4EH)
		DB	23 DUP(4EH)
		DB	23 DUP(4EH)
		DB	23 DUP(4EH)
HELP_MENU_ATTR2	DB	23 DUP(07H)	;ASCII menu
		DB	23 DUP(07H)
		DB	23 DUP(07H)
		DB	23 DUP(07H)
		DB	23 DUP(07H)

;------------------------------------------------------------------;
; SNIPPER BUILDS THE WINDOW AND ACCEPTS COMMANDS FROM THE KEYBOARD ;
;------------------------------------------------------------------;
SNIPPER		PROC	NEAR
		ASSUME	DS:CSEG, ES:BIOS_SEG
		XOR	BX,BX		;BX IS INCREMENT FOR ROW/COLUMN
GET_KB_KEY1:
		MOV	DX,TOP_LEFT	;GET LOCATION OF FIRST CORNER
		ADD	DH,BH		;ADD IN THE ROW INCREMENT
		ADD	DL,BL		;ADD IN THE COLUMN INCREMENT
		CMP	DL,0		;AT LEFT EDGE OF SCREEN?
		JGE	NOT_LEFT_EDGE
		MOV	DL,CRT_COLS	;JUMP TO THE RIGHT EDGE
		DEC	DL
NOT_LEFT_EDGE:
		CMP	DL,CRT_COLS	;AT RIGHT EDGE OF SCREEN YET?
		JB	NOT_RIGHT_EDGE	;IF NOT, KEEP MOVING RIGHT
		XOR	DL,DL		;IF YES, WRAP TO LEFT EDGE
NOT_RIGHT_EDGE:
		CMP	DH,0		;AT TOP OF SCREEN YET?
		JGE	NOT_AT_TOP
		MOV	DH,ROWS		;JUMP DOWN TO THE BOTTOM
NOT_AT_TOP:
		CMP	DH,ROWS		;AT BOTTOM OF SCREEN?
		JLE	NOT_AT_BOTTOM
		XOR	DH,DH		;JUMP BACK TO THE TOP
NOT_AT_BOTTOM:
		MOV	TOP_LEFT,DX	;SAVE NEW CORNER LOCATION
		CALL	REV_VIDEO	;CHANGE IT TO REVERSE VIDEO
		XOR	AH,AH		;BIOS KEYBOARD INPUT
		INT	16H		;GET A KEYSTROKE
		PUSH	AX
		CALL	REV_VIDEO	;PUT ATTRIBUTE BACK TO NORMAL
		POP	AX
		CMP	AH,1		;IS IT ESCAPE?
		JNE	NOT_ESC
		RET			;JUST RETURN TO EXIT
NOT_ESC:
		MOV	BX,0FF00H	;INCREMENT TO SUBTRACT ONE ROW
		CMP	AH,48H		;IS IT UP ARROW?
		JE	GET_KB_KEY1
		MOV	BX,0100H	;INCREMENT TO ADD ONE ROW
		CMP	AH,50H		;IS IT DOWN ARROW?
		JE	GET_KB_KEY1
		
		MOV	BX,0001H	;INCREMENT TO ADD ONE COLUMN
		CMP	AH,4FH		;IS IT END KEY?
		JE	END_HIT		;jump to END_hit
		
		MOV	BX,0001H	;INCREMENT TO ADD ONE COLUMN
		CMP	AH,52H		;IS IT INS KEY?
		JE	INS_HIT	;jump to PLUS_hit

		MOV	BX,0001H	;INCREMENT TO ADD ONE COLUMN
		CMP	AH,4DH		;IS IT RIGHT ARROW?
		JE	GET_KB_KEY1
		
		MOV	BX,00FFH	;INCREMENT TO SUBTRACT ONE COLUMN
		CMP	AH,47H		;Is it home key
		JE	HOME_HIT	;jump to home_hit

		MOV	BX,00FFH	;INCREMENT TO SUBTRACT ONE COLUMN
		CMP	AH,4BH		;IS IT LEFT ARROW?
		JNE	NOT_LEFT_ARROW
		JMP	GET_KB_KEY1
NOT_LEFT_ARROW:
		XOR	BX,BX
		CMP	AL,13		;IS IT A CARRIAGE RETURN?
		JNE	NOT_CR
		MOV	DX,TOP_LEFT	;A CARRIAGE RETURN WAS PRESSED
		MOV	BOT_RIGHT,DX	;INITIALIZE THE SECOND CORNER
		CALL	REV_VIDEO	;CHANGE IT BACK TO REVERSE VIDEO
		JMP	SHORT GET_KB_KEY2
NOT_CR:
		JMP	GET_KB_KEY1	;JUST GET ANOTHER KEY
HOME_HIT:
		MOV	DL,0		;put cursor at beginning of line
		MOV	BL,0		;
		PUSH	DX
		MOV	DX,TOP_LEFT
		MOV	DL,0H
		MOV	TOP_LEFT,DX
		POP	DX
		JMP	GET_KB_KEY1	;JUST GET ANOTHER KEY
END_HIT:
		MOV	BL,0H		;put cursor at end of line.
		MOV	DL,0H		;
		PUSH	DX
		MOV	DX,TOP_LEFT
		MOV	DL,4FH
		MOV	TOP_LEFT,DX
		POP	DX
		JMP	GET_KB_KEY1	;JUST GET ANOTHER KEY
INS_HIT:
		MOV	BL,0H		;put cursor at 34th column
		MOV	DL,0H		;
		PUSH	DX
		MOV	DX,TOP_LEFT
		MOV	DL,21H
		MOV	TOP_LEFT,DX
		POP	DX
		JMP	GET_KB_KEY1	;JUST GET ANOTHER KEY
GET_KB_KEY2:
		MOV	HOME_END_HIT,0000H	;clear flag for home/end key
		XOR	AH,AH
		INT	16H		;GET A KEYSTROKE
GOT_KEY2:	MOV	DX,BOT_RIGHT
		CMP	AH,48H		;IS IT UP ARROW?
		JNE	NEXT_1
		JMP	SUB_ROW_1	;SUBTRACT A ROW FROM WINDOW
NEXT_1:
		CMP	AH,50H		;IS IT DOWN ARROW?
		JNE	NEXT_2
		JMP	ADD_ROW_1	;ADD A ROW TO THE WINDOW
NEXT_2:	
		CMP	AH,4DH		;IS IT RIGHT ARROW?
		JNE	NEXT_3
		JMP	ADD_COL		;ADD A COLUMN TO THE WINDOW
NEXT_3:
		CMP	AH,4BH		;IS IT LEFT ARROW?
		JNE	NEXT_4
		JMP	SUB_COL		;SUBTRACT A COLUMN FROM WINDOW
NEXT_4:
		CMP	AH,47H		;is it home key.
		JNE	NEXT_5
		MOV	HOME_END_HIT,0001H
		MOV	HOME_END_LOOP,01H
		JMP	SUB_COL	
NEXT_5:
		CMP	AH,4FH		;is it end key?
		JNE	NEXT_6
		MOV	HOME_END_HIT,0100H
		JMP	ADD_COL
NEXT_6:
		JMP	NOT_ARROW_KEY
SUB_COL:
		CMP	DH,TOP_ROW
		JG	OK_GO_BACK
		CMP	DL,LEFT_SIDE	;DONT ERASE IT COMPLETELY
		JLE	GET_KB_KEY2
OK_GO_BACK:
		CMP	DL,0		;DONT ERASE IT COMPLETELY
		JLE	GET_KB_KEY2
		DEC	DL		;SUBTRACT A COLUMN
		MOV	RIGHT_SIDE,DL	;SAVE NEW RIGHT SIDE COLUMN
		INC	DL
DONT_INC_DL:
		JMP	SHORT COL_LOOP
ADD_COL:
		INC	DL		;ADD A COLUMN
		CMP	DL,CRT_COLS	;AT RIGHT EDGE OF SCREEN?
		JL	ADD_COL_1
		JMP	GET_KB_KEY2	;STOP WHEN SCREEN IS FILLED
ADD_COL_1:
		MOV	RIGHT_SIDE,DL	;SAVE NEW RIGHT SIDE COLUMN
COL_LOOP:
		CMP	HOME_END_HIT,0001H
		JZ	COL_LOOP_1
		CMP	HOME_END_HIT,0100H
		JZ	COL_LOOP_2
		CALL	REV_VIDEO	;REVERSE THIS CHARACTER
		JMP	GET_KB_KEY2
COL_LOOP_1:
		CALL	REV_VIDEO	;REVERSE THIS CHARACTER
		DEC	DL
		JMP	SUB_COL
COL_LOOP_2:
		CALL	REV_VIDEO	;REVERSE THIS CHARACTER
		JMP	ADD_COL
SUB_ROW_1:
		CMP	DH,TOP_ROW	;AT TOP OF WINDOW?
		JG	SUB_ROW_2
		JMP	GET_KB_KEY2	;DONT ERASE IT COMPLETELY
SUB_ROW_2:
		PUSH	DX
SUB_ROW:
		CALL	REV_VIDEO
		DEC	DL		;SUBTRACT A COLUMN
		CMP	DL,0		;DONT ERASE IT COMPLETELY
		JL	SUB_ROW_PLUS
		JMP	SUB_ROW
SUB_ROW_PLUS:
		POP	DX
		PUSH	CX
		MOV	CX,TOP_LEFT
		INC	CH
		CMP	CH,DH
		JE	ON_SECOND_ROW
		JMP	SUB_ROW_PLUS_1
ON_SECOND_ROW:		
		CMP	CL,DL
		JLE	SUB_ROW_PLUS_1
		MOV	DL,CL
		MOV	BOT_RIGHT,DX
SUB_ROW_PLUS_1:
		POP	CX
		DEC 	DH
		MOV	BOT_ROW,DH
		PUSH	DX
SUB_ROW_PLUS_2:
		CMP	DL,79
		JGE	AT_END
		INC	DL
		CALL	REV_VIDEO
		JMP	SUB_ROW_PLUS_2
AT_END:		
		POP	DX
		JMP	GET_KB_KEY2
		
		
ADD_ROW_1:
		CMP	DH,ROWS		;AT BOTTOM OF SCREEN?
		JL	ADD_ROW_1_1
		JMP	GET_KB_KEY2	;STOP WHEN SCREEN IS FILLED
ADD_ROW_1_1:
		PUSH	DX
ADD_ROW:
		CMP	DL,79
		JZ	SKIP_INC
		INC 	DL
		CALL	REV_VIDEO
SKIP_INC:
		CMP	DL,78
		JG	ADD_ROW_PLUS
		JMP 	ADD_ROW
ADD_ROW_PLUS:
		POP	DX
		CMP	DH,ROWS		;AT BOTTOM OF SCREEN?
		JL	NOT_BOT
		JMP	GET_KB_KEY2	;STOP WHEN SCREEN IS FILLED
NOT_BOT:
		INC	DH
		MOV	BOT_ROW,DH
ROW_LOOP:
		CALL	REV_VIDEO	;REVERSE THIS CHARACTER
		DEC	DL		;MOVE TO NEXT COLUMN
		CMP	DL,0		;AT LEFT EDGE YET?
		JGE	ROW_LOOP	;CONTINUE UNTIL AT LEFT EDGE
		JMP	GET_KB_KEY2
NOT_ARROW_KEY:
		CMP	AH,19H		;WAS IT THE "P" KEY?
		JNE	NOT_P
		MOV	SEND_CHAR,OFFSET PRINT_CHAR
		JMP	FORMAT_OUTPUT
NOT_P:
		MOV	BUFF_NEXT,BUFF_START
		MOV	BUFF_LAST,BUFF_START
		MOV	FILE_BUFF_NEXT,FILE_BUFF_START
		MOV	FILE_BUFF_LAST,FILE_BUFF_START
		MOV	SEND_CHAR,OFFSET BUFF_CHAR
		CMP	AH,21H		;IS IT THE "F" KEY
		JNE	NOT_F
		MOV	WRIT_FILE,0
		MOV	FILE_SEND_CHAR,OFFSET FILE_BUFF_CHAR
		CALL	GET_FILENAME
		CMP	WRIT_FILE,-1	;WAS ESCAPE REQUESTED?
		JE	ERASE_BOX
		CALL	FORMAT_OUTPUT
		MOV	WRIT_FILE,1
		MOV	FILE_SEND_KEYS,01H
		TEST	BUSY_FLAGS,00000011B 	;IS INT21 OR INT13 BUSY?
		JNZ	RETURN		;IF YES, WAIT TILL LATER
		CALL	WRITE_TO_FILE	;IF NOT, DO IT NOW
RETURN:
		RET
NOT_F:
		CMP	AH,1		;IS IT ESCAPE?
		JE	ERASE_BOX ;IF YES, ERASE BOX AND EXIT
		CMP	AL,13		;IS IT A CARRIAGE RETURN?
		JE	DISPLAY_HELP	;IF YES, DISPLAY HELP
		JMP	GET_KB_KEY2	;OTHERWISE JUST GET ANOTHER KEY
ERASE_BOX:
		MOV	SEND_CHAR,OFFSET RETURN
		JMP	FORMAT_OUTPUT
DISPLAY_HELP:
		CALL	EXCHANGE_HELP	;PUT UP THE HELP MENU
		XOR	AH,AH
		INT	16H		;GET ANOTHER KEYSTROKE
		PUSH	AX		;SAVE THE KEYSTROKE
		CALL	EXCHANGE_HELP	;PULL DOWN THE HELP MENU
		POP	AX		;GET BACK THE KEYSTROKE
		JMP	GOT_KEY2
;*********************************************************************
REV_VIDEO:
		CALL	READ_CHAR	;READ CHARACTER AND ATTRIBUTE
		MOV	BL,AH		;SAVE ATTRIBUTE IN BL
		AND	BL,10001000B	;GET BLINK AND INTENSITY BITS
		AND	AH,01110111B	;NOW LOOK ONLY AT COLOR BITS
		MOV	CL,4		;ROTATE FOUR COUNTS
		ROR	AH,CL		;ROTATE FOREGROUND AND BACKGROUND
		OR	BL,AH		;PUT BACK BLINK AND INTENSITY BITS
		CALL	DISPLAY_CHAR	;WRITE CHARACTER AND ATTRIBUTE
		RET
;*********************************************************************
;---------------------------------------------------------------------;
; Proceedure to read char off screen, and send to file formatted.
; 11-05-90  12:15am
;---------------------------------------------------------------------;
FORMAT_OUTPUT:	
		PUSH	AX
		PUSH	BX
		PUSH	CX
		PUSH	DX
		MOV	DX,TOP_LEFT	;GET LOCATION OF FIRST CORNER
		MOV	SPACE_FLAG,00H
		MOV	PUNCT_FLAG,00H
		MOV	CHARS_ON_STACK,00H
READ_LOOP_NEW:
		CALL	REV_VIDEO
		CALL	READ_CHAR
		CMP	AL,20H
		JNE	READ_LOOP_NEW_1
		JMP	WAS_SPACE
READ_LOOP_NEW_1:
		CMP	AL,7CH
		JNE	NOT_PIPE
		JMP	MOVE_TO_NEXT_CHAR
NOT_PIPE:
		CMP	AL,21H		;is it a "!"
		JNE	NOT_PIPE_1
		JMP	PUNCT
NOT_PIPE_1:
		CMP	AL,2EH		;is it a "."
		JNE	NOT_PERIOD
		JMP	PUNCT
NOT_PERIOD:
		CMP	AL,3FH		;is it a "?"
		JNE	NOT_QUESTION
		JMP	PUNCT
NOT_QUESTION:
		CMP	AL,3AH		;is it a ":"
		JNE	NOT_COLON
		JMP	PUNCT
NOT_COLON:
		CMP	AL,3BH		;is it a ";"
		JNE	NOT_SEMICOLON
		JMP	PUNCT
NOT_SEMICOLON:
READ_NEW_1:
		CMP	SPACE_FLAG,01
		JE	SPACE_SET
		CALL	SEND_CHAR
		INC	CHARS_ON_STACK
MOVE_TO_NEXT_CHAR:
		CMP	DH,BOT_ROW
		JE	LAST_LINE_NEW
		INC	DL
		CMP 	DL,79
		JG	MOVE_1
		JMP	READ_LOOP_NEW
MOVE_1:
		CALL	CR_LF
		MOV	CHARS_ON_STACK,00H
		MOV	SPACE_FLAG,00H
		MOV	PUNCT_FLAG,00H
		INC	DH
		MOV	DL,0
		CMP	DH,BOT_ROW
		JG	MOVE_3
		JMP	READ_LOOP_NEW
MOVE_3:
		CALL	REV_VIDEO
LAST_LINE_NEW:
		INC 	DL
		CMP	DL,RIGHT_SIDE
		JG	LAST_LINE_NEW_1
		JMP 	READ_LOOP_NEW
LAST_LINE_NEW_1:
		CALL	CR_LF
		POP	DX
		POP	CX
		POP	BX
		POP	AX
		RET
SPACE_SET:
		CMP	CHARS_ON_STACK,0
		JE	NO_PUNCT_FLAG
		PUSH	AX
		MOV	AX,0020H
		CALL 	SEND_CHAR
		POP	AX
		INC	CHARS_ON_STACK
		CMP	PUNCT_FLAG,01H 
		JNE	NO_PUNCT_FLAG
		MOV	PUNCT_FLAG,00H
		PUSH	AX
		MOV	AX,0020H
		CALL 	SEND_CHAR
		POP	AX
		INC	CHARS_ON_STACK
		CALL	SEND_CHAR
		INC	CHARS_ON_STACK
		MOV	SPACE_FLAG,00H
		JMP	MOVE_TO_NEXT_CHAR
NO_PUNCT_FLAG:
		CALL 	SEND_CHAR
		INC	CHARS_ON_STACK
		MOV	SPACE_FLAG,00H
		JMP	MOVE_TO_NEXT_CHAR
PUNCT:
		CMP	CHARS_ON_STACK,0
		JNE	PUNCT_1
		JMP	READ_NEW_1
PUNCT_1:
		MOV	PUNCT_FLAG,01H
		JMP	READ_NEW_1
WAS_SPACE:
		MOV	SPACE_FLAG,01H	
		JMP	MOVE_TO_NEXT_CHAR
;*********************************************************************
CR_LF:
		MOV	AL,13
		CALL	SEND_CHAR	;SEND A CARRIAGE RETURN
		MOV	AL,10
		CALL	SEND_CHAR	;SEND A LINE FEED
		RET
;*********************************************************************
DISPLAY_CHAR:
		PUSH	BX		;SAVE THE ATTRIBUTE
		CALL	GET_CURS_ADDR	;GET ADDRESS OF BIOS CURSOR
		MOV	ES:[BX],DX	;TELL BIOS WHERE THE CURSOR IS
		POP	BX		;GET BACK THE ATTRIBUTE
		MOV	BH,ACTIVE_PAGE	;GET ACTIVE PAGE
		PUSH	CX		;SAVE THE LOOP COUNT
		MOV	CX,1		;WRITE 1 CHARACTER
		MOV	AH,9		;WRITE CHARACTER AND ATTRIBUTE
		INT	10H
		POP	CX		;RECOVER LOOP COUNT
		RET			;DONE WRITING THE CHARACTER
;*********************************************************************
READ_CHAR:
		CALL	GET_CURS_ADDR	;GET ADDRESS OF BIOS CURSOR
		MOV	ES:[BX],DX	;TELL BIOS WHERE THE CURSOR IS
		MOV	BH,ACTIVE_PAGE	;GET ACTIVE PAGE
		MOV	AH,8		;BIOS FUNCTION TO READ CHARACTER
		INT	10H		;READ THE CHARACTER/ATTRIBUTE
		RET
;*********************************************************************
PRINT_CHAR:
		PUSH	DX
		XOR	AH,AH		;USE FUNCTION 0
		XOR	DX,DX		;PRINTER NUMBER 0
		INT	17H		;BIOS PRINT CHARACTER FUNCTION
		ROR	AH,1		;LOOK AT BIT ZERO
		JNC	PRINT_OK	;DID A TIMEOUT OCCUR?
		MOV	SEND_CHAR,OFFSET RETURN
PRINT_OK:
		POP	DX
		RET			;DONE PRINTING CHARACTER
;*********************************************************************
BUFF_CHAR:
		MOV	BX,BUFF_LAST	;GET LOCATION OF LAST CHARACTER
		MOV	[BX],AL		;PUT THE CHARACTER IN BUFFER
		INC	BX		;ADVANCE THE POINTER
		MOV	BUFF_LAST,BX	;CHECK FOR BUFFER FULL
		CMP	BX,BUFF_END	;IS THE BUFFER FULL YET?
		JNE	BUFF_OK		;IF NOT, KEEP GOING
		MOV	SEND_CHAR,OFFSET RETURN
BUFF_OK:
		RET			;NOW ITS IN THE BUFFER
;*********************************************************************
FILE_BUFF_CHAR:
		MOV	BX,FILE_BUFF_LAST	;GET LOCATION OF LAST CHARACTER
		MOV	[BX],AL		;PUT THE CHARACTER IN BUFFER
		INC	BX		;ADVANCE THE POINTER
		MOV	FILE_BUFF_LAST,BX	;CHECK FOR BUFFER FULL
		CMP	BX,FILE_BUFF_END	;IS THE BUFFER FULL YET?
		JNE	FILE_BUFF_OK		;IF NOT, KEEP GOING
		MOV	FILE_SEND_CHAR,OFFSET RETURN
FILE_BUFF_OK:
		RET			;NOW ITS IN THE BUFFER
;*********************************************************************
GET_CURS_ADDR:
		MOV	BL,ACTIVE_PAGE	;GET THE CURRENT PAGE NUMBER
		XOR	BH,BH		;CONVERT TO A WORD OFFSET
		SHL	BX,1		;TIMES TWO FOR A WORD
		ADD	BX,OFFSET CURSOR_POSN ;ADD IN BASE ADDRESS
		RET
;*********************************************************************
EXCHANGE_HELP:
		XOR	DX,DX		;START AT TOP LEFT CORNER
		PUSH	DI
		LEA	SI,HELP_MENU
		MOV	AH,15
		INT	10H
		CMP	AL,7
		JE	MONO_HELP
		LEA	DI,HELP_MENU_ATTR1
		JMP	EXCHANGE_LOOP
MONO_HELP:
		LEA	DI,HELP_MENU_ATTR2
EXCHANGE_LOOP:
		CMP	DL,23		;AT LAST COLUMN IN THIS ROW YET?
		JL	SWAP_CHAR
		XOR	DL,DL		;BACK TO FIRST COLUMN
		INC	DH		;DO THE NEXT ROW
		CMP	DH,5		;AT LAST ROW YET?
		JL	SWAP_CHAR	;QUIT WHEN LAST ROW IS DONE
		POP	DI
		RET
SWAP_CHAR:
		CALL	READ_CHAR	;READ CHARACTER AT THIS POSITION
		XCHG	AL,CS:[SI]	;SWAP WITH THE HELP TEXT
		XCHG	AH,CS:[DI]	;SWAP WITH THE HELP TEXT
		MOV	BL,AH		;ATTRIBUTE IS THE SAME
		CALL	DISPLAY_CHAR	;PUT NEW CHARACTER ON SCREEN
		INC	DL		;POINT TO NEXT POSITION
		INC	SI
		INC	DI
		JMP EXCHANGE_LOOP
;*********************************************************************
TEST_FILENAME_CHAR:
		CMP	AL,2EH
		JE	FILECHAR_1
		CMP	AL,20H
		JLE	FILECHAR_1
		CMP	AL,22H
		JE	FILECHAR_1
		CMP	AL,25H
		JE	FILECHAR_1
		CMP	AL,2AH
		JE	FILECHAR_1
		CMP	AL,2BH
		JE	FILECHAR_1
		CMP	AL,2CH
		JE	FILECHAR_1
		CMP	AL,2FH
		JE	FILECHAR_1
		CMP	AL,3AH
		JE	FILECHAR_1
		CMP	AL,3BH
		JE	FILECHAR_1
		CMP	AL,3CH
		JE	FILECHAR_1
		CMP	AL,3DH
		JE	FILECHAR_1
		CMP	AL,3EH
		JE	FILECHAR_1
		CMP	AL,7FH
		JGE	FILECHAR_1
		CMP	AL,5BH
		JE	FILECHAR_1
		CMP	AL,5CH
		JE	FILECHAR_1
		CMP	AL,5DH
		JE	FILECHAR_1
		CMP	AL,5EH
		JE	FILECHAR_1
		CMP	AL,60H
		JE	FILECHAR_1
		CMP	FILE_EXT,00H
		JE	NOT_EXTEN
		CMP	CL,04H
		JE	FILECHAR_1
		RET
NOT_EXTEN:
		CMP	CL,08H
		JE	FILECHAR_1
		RET
FILECHAR_1:
		MOV	FILECHAR,01
		RET
GET_FILENAME:
		PUSH	BX
		PUSH	AX
		MOV	AX,0046H
		CALL	FILE_SEND_CHAR
		MOV	AX,004CH
		CALL	FILE_SEND_CHAR
		MOV	AX,0020H
		CALL	FILE_SEND_CHAR
		POP	AX
		PUSH	DI
		PUSH	SI
		MOV	FILE_EXT,00H
		MOV	FILECHAR,00H
		PUSH	DX
		PUSH	CX
		MOV	CL,00H
		MOV	DX,TOP_LEFT
		MOV	DL,0
		LEA	SI,FILENAME
GET_FILENAME_1:
		CALL	READ_CHAR
		CALL	TEST_FILENAME_CHAR
		CMP	FILECHAR,00H
		JNE	END_OF_FILENAME_1
		CMP	FILE_EXT,00H
		JNE	FILE_EXTEN
		MOV	CS:[SI],AL
		INC	SI
FILE_EXTEN:
		CALL	FILE_SEND_CHAR
		INC	DL
		INC	CL
		JMP	GET_FILENAME_1
END_OF_FILENAME_1:
		CMP	CL,0
		JE 	END_OF_FILENAME_A
		CMP	FILE_EXT,01H
		JE	AT_END_OF_FILENAME
		MOV	FILECHAR,00H
		MOV	FILE_EXT,01H
		JMP	FILE_EXTEN
AT_END_OF_FILENAME:
		MOV	AL,0AH
		CALL	FILE_SEND_CHAR
		MOV	AL,0DH
		CALL	FILE_SEND_CHAR
		MOV	AL,2EH
		MOV	CS:[SI],AL
		INC	SI
		MOV	AL,52H
		MOV	CS:[SI],AL
		INC	SI
		MOV	AL,54H
		MOV	CS:[SI],AL
		INC	SI
		MOV	AL,54H
		MOV	CS:[SI],AL
		INC	SI
FILL_TO_END:
		CMP	CL,0DH
;		CMP	CL,18H
		JE	END_OF_FILENAME_A
		MOV	AL,0H
		MOV	CS:[SI],AL
		INC	CL
		INC	SI
		JMP	FILL_TO_END
END_OF_FILENAME_A:
		POP	CX
		POP	DX
		LEA	SI,FILE_PROMPT	;POINT TO THE PROMPT FOR SOURCE
		XOR	DI,DI		;USE THE PSP FOR BUFFER
		XOR	DX,DX		;PUT PROMPT AT TOP LEFT CORNER
		MOV	CX,29		;USE MAX OF 40 CHARACTERS
		POP	BX
DISPLAY_PROMPT:
		PUSH	CX		;SAVE LOOP COUNT
		CALL	READ_CHAR	;GET CHARACTER ON THIS LINE
		MOV	CS:[DI],AX	;STORE IT IN THE PSP
		INC	DI		;ADD TWO FOR NEXT CHARACTER
		INC	DI
		MOV	AL,CS:[SI]	;GET NEXT PROMPT CHARACTER
		INC	SI		;NEXT CHARACTER IN PROMPT
		MOV	BL,47H		;ATTRIBUTE FOR PROMPT
		CALL	DISPLAY_CHAR	;PUT UP THE PROMPT CHARACTER
		INC	DL		;POINT TO NEXT COLUMN
		POP	CX		;GET BACK LOOP COUNT
		LOOP	DISPLAY_PROMPT	;ENTIRE PROMPT AND FILENAME
FIND_LAST_LETTER:
		DEC	SI		;BACKUP TO LAST LETTER
		DEC	DL		;BACKUP TO LAST COLUMN
		CMP	BYTE PTR [SI],0	;IS THIS A LETTER?
		JE	FIND_LAST_LETTER;BACKUP UNTILL A LETTER IS FOUND
		INC	DL		;PUT BLINKING BOX AT LAST LETTER
READ_KB:
		MOV	AL,219		;ASCII FOR BOX CHARACTER
		MOV	BL,47H+80H	;MAKE IT A BLINKING BOX CHARACTER
		CALL	DISPLAY_CHAR	;WRITE THE BLINKING BOX
		XOR	AH,AH		;FUNCTIO 0 TO GET NEXT KEY
		INT	16H		;BIOS KEYBOARD INPUT
		CMP	AL,13		;IS IT A CARRIAGE RETURN?
		JE	ERASE_PROMPT
		CMP	AL,8		;IS IT A BACKSPACE?
		JE	BACK_SPACE
		CMP	AH,1		;IS IT ESCAPE?
		JNE	READ_KBDRD_2
		MOV	WRIT_FILE,-1	;INDICATE ESCAPE IS REQUESTED
READ_KBDRD_1:
		CMP	DL,16		;AT BEGINNING OF LINE?
		JLE	READ_KB		;IF YES, CAN'T BACKUP FROM HERE
		MOV	AL,0		;WRITE A NORMAL BLANK (ASCII 0)
		MOV	BL,47H		;ATTRIBUTE FOR FILENAME
		CALL	DISPLAY_CHAR	;WRITE THE LETTER
		DEC	DL		;BACKUP THE CURSOR
		JMP	READ_KBDRD_1
READ_KBDRD_2:
		CMP	AL,"."		;IS IT A VALID LETTER?
		JL	READ_KB
		CMP	AL,"z"		;IS IT A VALID LETTER?
		JG	READ_KB
		CMP	DL,28		;ONLY ALLOW 40 CHARACTERS
		JGE	READ_KB
TTY_KEY:

		MOV	WRIT_FILE,0	;FIX ESCAPE HIT THEN CHARS.
		MOV	BL,47H		;ATTRIBUTE FOR FILENAME
		CALL	DISPLAY_CHAR	;WRITE THE LETTER
		INC	DL		;MOVE TO NEXT COLUMN
		JMP	READ_KB		;GET ANOTHER KEYSTROKE
BACK_SPACE:
		CMP	DL,16		;AT BEGINNING OF LINE?
		JLE	READ_KB		;IF YES, CAN'T BACKUP FROM HERE
		MOV	AL,0		;WRITE A NORMAL BLANK (ASCII 0)
		MOV	BL,47H		;ATTRIBUTE FOR FILENAME
		CALL	DISPLAY_CHAR	;WRITE THE LETTER
		DEC	DL		;BACKUP THE CURSOR
		JMP	READ_KB		;THEN GET THE NEXT KEY
ESC_RET:
		MOV	WRIT_FILE,-1	;INDICATE ESCAPE IS REQUESTED
ERASE_PROMPT:
		XOR	AL,AL		;GET RID OF THE CURSOR
		CALL	DISPLAY_CHAR	;WRITE THE LETTER
		LEA	DI,FILE_PROMPT	;COPY TO FILENAME
		XOR	SI,SI		;COPY FROM PSP
		XOR	DX,DX		;PROMPT IS AT ROW ZERO
		MOV	CX,29		;COPY ALL 40 CHARACTERS
ERASE_LOOP:
		CALL	READ_CHAR	;GET CHARACTER ON THIS LINE
		MOV	CS:[DI],AL	;PUT IN BACK IN MEMORY
		INC	DI
		MOV	AX,CS:[SI]	;GET THE ORIGINAL CHARACTER BACK
		MOV	BL,AH		;PUT ATTRIBUTE INTO BL
		INC	SI
		INC	SI
		CALL	DISPLAY_CHAR	;WRITE ORIGINAL CHARACTER
		INC	DL		;MOVE TO NEXT COLUMN
		LOOP	ERASE_LOOP	;ERASE THE ENTIRE PROMPT
		POP	SI
		POP	DI
		RET
SNIPPER		ENDP

;---------------------------------------------------------------------;
; THIS COPIES THE BUFFER CONTENTS TO A FILE. IT SHOULD ONLY BE CALLED ;
; WHEN DOS IS IN A STABLE AND REENTRANT CONDITION.                    ;
;---------------------------------------------------------------------;
WRITE_TO_FILE	PROC	NEAR
		ASSUME	DS:NOTHING, ES:NOTHING
		MOV	WRIT_FILE,0	;TURN OFF REQUEST FLAG
		PUSH	AX		;MUST PRESERVE ALL REGISTERS
		PUSH	BX
		PUSH	CX
		PUSH	DX
		PUSH	DS
		PUSH	ES
		PUSH	CS
		POP	DS
		ASSUME	DS:CSEG		;DS POINTS TO OUR CODE SEGMENT
	     	MOV	AX,3524H	;GET DOS CRITICAL ERROR VECTOR
		INT	21H		;DOS FUNCTION TO GET VECTOR
		PUSH	BX		;SAVE OLD VECTOR ON STACK
		PUSH	ES
; REPLACE THE DOS SEVERE ERROR INTERRUPT WITH OUR OWN ROUTINE.
		MOV	DX,OFFSET NEWINT24
		MOV	AX,2524H	;SETUP TO CHANGE INT 24h VECTOR
		INT	21H		;CHANGE DOS SEVERE ERROR VECTOR
		LEA	SI,PATH_N_FILE
PATH_N_FILE_LOOP:
		CMP	BYTE PTR[SI],0
		JE	PNFL_DONE
		MOV	BYTE PTR[SI],0
		INC	SI
		JMP	PATH_N_FILE_LOOP
PNFL_DONE:
		LEA	DI,PATH_N_FILE
		LEA	SI,FILE_PATH
TRANSFER_PATH_N_FILE:
		CMP	BYTE PTR[SI],0
		JE	TPNF_DONE
		PUSH	BX
		MOV	BL,[SI]
		MOV	[DI],BL
		POP	BX
		INC	SI
		INC	DI
		JMP 	TRANSFER_PATH_N_FILE
TPNF_DONE:
		LEA	SI,FILENAME
ADD_FILENAME_LOOP:
		CMP	BYTE PTR[SI],0
		JE	AFL_DONE
		PUSH	BX
		MOV	BL,[SI]
		MOV	[DI],BL
		POP	BX
		INC	SI
		INC	DI
		JMP	ADD_FILENAME_LOOP
AFL_DONE:
		MOV	DX,OFFSET PATH_N_FILE	;POINT TO FILENAME
;		MOV	DX,OFFSET FILENAME ;POINT TO FILENAME
; FIRST TRY TO OPEN THE FILE.  IF DOS RETURNS WITH THE CARRY FLAG SET,
; THE FILE DIDN'T EXIST AND WE MUST CREATE IT.  ONCE THE FILE IS OPENED,
; ADVANCE THE FILE POINTER TO THE END OF FILE TO APPEND.
		MOV	AX,3D02H	;DOS FUNCTION TO OPEN FILE
		INT	21H		;DOS WILL RETURN WITH CARRY FLAG
		JC	FILE_NOT_FOUND	;SET IF FILE DOESN'T EXIST.
		MOV	BX,AX		;KEEP HANDLE IN BX ALSO
		XOR	CX,CX		;MOVE DOS FILE POINTER TO THE
		XOR	DX,DX		;END OF THE FILE. THIS LETS US
		MOV	AX,4202H	;APPEND THIS TO AN EXISTING FILE
		INT	21H		;DOS FUNCTION TO MOVE POINTER
		JNC	WRITE_FILE	;IF NO ERROR, CONTINUE TO WRITE
DOS_ERROR:
		CMP	ERR_STAT,0	;DID A SEVERE ERROR OCCUR?
		JNE	REP_VECTOR	;IF SEVERE ERROR, JUST QUIT
		JMP	SHORT CLOSE_FILE;JUST CLOSE THE FILE

FILE_NOT_FOUND:	CMP	ERR_STAT,0	;DID A SEVERE ERROR OCCUR?
		JNE	REP_VECTOR	;IF SEVERE ERROR, JUST QUIT
		MOV	CX,0020H	;ATTRIBUTE FOR NEW FILE
		MOV	AH,3CH		;CREATE FILE FOR WRITING
		INT	21H		;DOS FUNCTION TO CREATE FILE
		JC	DOS_ERROR   	;ON ANY ERROR, TAKE JUMP
		MOV	BX,AX		;SAVE HANDLE IN BX
WRITE_FILE:     MOV	DX,BUFF_START	;POINT TO BUFFER
		MOV	CX,BUFF_LAST	;GET BUFFER POINTER
		SUB	CX,DX		;NUMBER OF CHARS IN BUFFER
		MOV	AH,40H		;DOS WRITE TO A DEVICE FUNCTION
		INT	21H		;WRITE TO THE FILE
CLOSE_FILE:
		MOV	AH,3EH		;DOS FUNCTION TO CLOSE THE FILE
		INT	21H
REP_VECTOR:
		POP	DS		;GET INT 24H VECTOR FROM STACK
		POP	DX
		MOV	AX,2524H	;RESTORE CRITICAL ERROR VECTOR
		INT	21H		;DOS FUNCTION TO CHANGE VECTOR
		POP	ES		;FINALLY RESTORE ALL REGISTERS
		POP	DS
		POP	DX
		POP	CX
		POP	BX
		POP	AX
		RET			;FINISHED WRITING TO DISK
WRITE_TO_FILE	ENDP
;---------------------------------------------------------------------;
; INTERRUPT 09 ROUTINE.  WATCH FOR TRIGGER KEY TO POP UP.
;---------------------------------------------------------------------;
NEWINT09	PROC	FAR
		ASSUME	DS:NOTHING, ES:NOTHING
		STI			;ALLOW OTHER INTERRUPTS
		PUSH	AX		;MUST SAVE PROCESSOR STATE
		IN	AL,60H		;GET THE SCAN CODE
		CMP	AL,HOTKEY	;IS IT THE HOT KEY?
		JE	TRIGGER		;IF YES, CHECK THE MASK
INT09_EXIT:	POP	AX		;RESTORE THE PROCESSOR STATE
		JMP	OLDINT09	;CONTINUE WITH ROM ROUTINE

TRIGGER:	MOV	AH,2		;GET KEYBOARD STATUS
		INT	16H		;BIOS KEYBOARD SERVICE

		AND	AL,0FH		;Take lower four bits
		CMP	AL,SHIFT_MASK	;IS CTL KEY DOWN?
		JNZ	INT09_EXIT	;IF NOT, IGNORE IT
		TEST	BUSY_FLAGS,00000100B ;IS SNIPPER ALREADY ACTIVE?
		JNZ	INT09_EXIT	;IF ACTIVE, THEN EXIT
		OR	BUSY_FLAGS,00000100B ;ITS ACTIVE NOW
		PUSHF
		CALL	OLDINT09	;LET ROM PROCESS THE KEY
		PUSH	BX		;MUST PRESERVE ALL REGISTERS
		PUSH	CX
		PUSH	DX
		PUSH	BP
		PUSH	SI
		PUSH	DI
		PUSH	DS
		PUSH	ES
		PUSH	CS
		POP	DS		;SET DS TO CSEG
		MOV	AX,BIOS_SEG	;ES POINTS TO BIOS DATA AREA
		MOV	ES,AX
		ASSUME	DS:CSEG, ES:BIOS_SEG
		CALL	GET_CURS_ADDR	;CURSOR ADDRESS FOR THIS PAGE
		PUSH	ES:[BX]		;SAVE THE CURSOR LOCATION
		CALL	SNIPPER		;DO THE WINDOW
		CALL	GET_CURS_ADDR	;CURS0R ADDRESS FOR THIS PAGE
		POP	ES:[BX]		;GET BACK CURSOR  POSITION
		AND	BUSY_FLAGS,11111011B  ;SNIPPER IS NOT ACTIVE
		POP	ES		;RESTORE ALL REGISTERS
		POP	DS
		POP	DI
		POP	SI
		POP	BP
		POP	DX
		POP	CX
		POP	BX
		POP	AX
		IRET			;NOW WERE ALL DONE
NEWINT09	ENDP
;---------------------------------------------------------------------;
; INTERRUPT 13 ROUTINE. SET BIOS BUST BIT                             ;
;---------------------------------------------------------------------;
NEWINT13	PROC	FAR
		ASSUME	DS:NOTHING, ES:NOTHING
		OR	BUSY_FLAGS,00000010B	;SET BIOS BUSY BIT
		PUSHF
		CALL	OLDINT13	;DO THE BIOS FUNCTION
		PUSHF			;SAVE RESULT FLAGS
		AND	BUSY_FLAGS,11111101B	;CLEAR BIOS BUSY BIT
		POPF			;GET BACK RESULT FLAGS
		STI			;MUST RETURN WITH INTERUPTS ON
		RET	2		;RETURN BIOS RESULT FLAGS
NEWINT13	ENDP
;---------------------------------------------------------------------;
; INTERRUPT 16 ROUTINE. INSERT KEYSTROKES FROM BUFFER                 ;
;---------------------------------------------------------------------;
NEWINT16	PROC	FAR
		ASSUME	DS:NOTHING, ES:NOTHING
		PUSH	BX
		CMP	SEND_KEYS,1	;SENDING KEYS FROM BUFFER?
		JE	INSERT_KEY	;IF YES, THEN GET NEXT ONE
		CMP	FILE_SEND_KEYS,1	;SENDING KEYS FROM BUFFER?
		JE	FILE_INSERT_KEY	;IF YES, THEN GET NEXT ONE
		CMP	WRIT_FILE,1	;ANYTHING TO WRITE TO DISK?
		JE	CHECK_DOS_STAT	;IF YES, THIS IS THE TIME
BIOS_KB:
		POP	BX
		JMP	OLDINT16	;JUST DO NORMAL KB ROUTINE
CHECK_DOS_STAT:
		CMP	DOS_STAT,0AH	;DOING READ STRING?
		JE	BEGIN_NOW	;IF YES, ITS SAFE TO BEGIN
		CMP	DOS_STAT,8	;DOING KEYBOARD INPUT?
		JNE	BIOS_KB		;IF YES, ITS SAFE TO BEGIN
BEGIN_NOW:
		STI			;GET INTERRUPTS BACK ON
		CALL	WRITE_TO_FILE	;EMPTY THE BUFFER
		JMP	BIOS_KB		;CONTINUE WITH BIOS ROUTINE
INSERT_KEY:
		STI			;INTERRUPTS BACK ON
		MOV	BX,BUFF_NEXT	;GET ADDRESS OF NEXT BYTE
		CMP	BX,BUFF_LAST	;AT END OF BUFFER YET?
		JL	GET_A_KEY	;IF NOT, GET THE NEXT ONE
		MOV	SEND_KEYS,0	;WHEN DONE, TURN OFF SEND SWITCH
GET_A_KEY:
		MOV	AL,CS:[BX]	;GET THE NEXT KEY CODE
		CMP	AL,10		;IS IT A LINE FEED?
		JNE	NOT_LF		;DONT RETURN THE LINE FEEDS
		INC	BUFF_NEXT	;SKIP TO NEXT KEY
		JMP	INSERT_KEY
NOT_LF:
		CMP	AH,1		;REQUEST FOR STATUS ONLY?
		JE	RETURN_STATUS	;IF YES, RETURN STATUS ONLY
		CMP	AH,0		;REQUEST TO GET THE NEXT KEY
		JNE	BIOS_KB		;IF NOT, IGNORE THIS FUNCTION
		INC	BX		;REMOVE THIS KEY FROM OUR BUFFER
		MOV	BUFF_NEXT,BX	;SAVE THE POINTER TO NEXT KEY
RETURN_STATUS:
		OR	BL,1		;CLEAR ZERO FLAG TO INDICATE A
		POP	BX		;KEY IS AVAILIABLE
		RET	2		;RETURN WITH THESE FLAGS
FILE_INSERT_KEY:
		STI			;INTERRUPTS BACK ON
		MOV	BX,FILE_BUFF_NEXT	;GET ADDRESS OF NEXT BYTE
		CMP	BX,FILE_BUFF_LAST	;AT END OF BUFFER YET?
		JL	FILE_GET_A_KEY	;IF NOT, GET THE NEXT ONE
		MOV	FILE_SEND_KEYS,0	;WHEN DONE, TURN OFF SEND SWITCH
FILE_GET_A_KEY:
		MOV	AL,CS:[BX]	;GET THE NEXT KEY CODE
		CMP	AL,10		;IS IT A LINE FEED?
		JNE	FILE_NOT_LF		;DONT RETURN THE LINE FEEDS
		INC	FILE_BUFF_NEXT	;SKIP TO NEXT KEY
		JMP	FILE_INSERT_KEY
FILE_NOT_LF:
		CMP	AH,1		;REQUEST FOR STATUS ONLY?
		JE	FILE_RETURN_STATUS	;IF YES, RETURN STATUS ONLY
		CMP	AH,0		;REQUEST TO GET THE NEXT KEY
		JNE	BIOS_KB		;IF NOT, IGNORE THIS FUNCTION
		INC	BX		;REMOVE THIS KEY FROM OUR BUFFER
		MOV	FILE_BUFF_NEXT,BX	;SAVE THE POINTER TO NEXT KEY
FILE_RETURN_STATUS:
		OR	BL,1		;CLEAR ZERO FLAG TO INDICATE A
		POP	BX		;KEY IS AVAILIABLE
		RET	2		;RETURN WITH THESE FLAGS
NEWINT16	ENDP
;---------------------------------------------------------------------;
; INTERRUPT 21 ROUTINE.  THIS ROUTINE IS USED TO MONITOR DOS FUNCTION ;
; CALLS. IF THE BUFFER NEEDS TO BE FLUSHED, IT WIL BE DONE HERE.      ;
;---------------------------------------------------------------------;
NEWINT21	PROC	FAR
		ASSUME	DS:NOTHING, ES:NOTHING
		STI
		OR	AH,AH		;DOING FUNCTION ZERO?
		JNE	NOT_ZERO
		MOV	AH,4CH		;IF YES, CHANGE IT TO A 4CH
NOT_ZERO:
		OR	BUSY_FLAGS,00000001B	;SET DOS BUSY BIT
		MOV	DOS_STAT,AH
		PUSHF			;SIMULATE AN INTERRUPT
		CALL	OLDINT21	;DO THE DOS FUNCTION
		PUSHF			;SAVE THE RESULT FLAGS
		AND	BUSY_FLAGS,11111110B	;CLEAR DOS BUSY BIT
		CMP	WRIT_FILE,1	;ANYTHING TO WRITE TO DISK?
		JNE	NO_WRITE	;IF NOT JUST RETURN
		CALL	WRITE_TO_FILE	;SAFE TO ACCESS DISK NOW
NO_WRITE:
		POPF			;RECOVER DOS RESULT FLAGS
		RET	2		;RETURN WITH DOS RESULT FLAGS
NEWINT21	ENDP
;---------------------------------------------------------------------;
; NEW INTERRUPT 24H (CRITICAL DOS ERROR).  THIS INTERRUPT IS ONLY IN  ;
; EFFECT ONLY DURING A WRITE SCREEN.  IT IS REQUIRED TO SUPPRESS THE  ;
; 'ABORT, RETRY, IGNORE' MESSAGE.  ALL FATAL DISK ERRORS ARE IGNORED. ;
;---------------------------------------------------------------------;
NEWINT24	PROC	FAR
		ASSUME	CS:CSEG, DS:NOTHING, ES:NOTHING
		STI			;TURN INTERRUPTS BACK ON
		INC 	ERR_STAT	;SET THE ERROR FLAG
 		XOR	AL,AL		;TELLS DOS TO IGNORE THE ERROR
		IRET			;THATS ALL WE DO HERE
NEWINT24	ENDP

;--------------------------------------------------------------------;
; HERE IS THE CODE USED TO INITIALIZE SNIPPER.                       ;
;--------------------------------------------------------------------;
		ASSUME	CS:CSEG, DS:CSEG, ES:CSEG
INITIALIZE:
		LEA	DX,COPYRIGHT
		MOV	AH,9		;DOS DISPLAY STRING SERVICE
		INT	21H		;DISPLAY TITLE MESSAGE
; SEARCH FOR AN PREVIOUSLY INSTALLED COPY OF SNIPPER
		NOT	BYTE PTR START	;MODIFY TO AVOID FASLE MATCH
		XOR	BX,BX		;START SEARCH AT SEGMENT ZERO
		MOV	AX,CS		;COMPARE TO THIS CODE SEGMENT
NEXT_SEGMENT:
		INC	BX		;LOOK AT NEXT SEGMENT
		CMP	AX,BX		;UNTIL REACHING THIS CODE SEG
		MOV	ES,BX
		JE	NOT_INSTALLED
		LEA	SI,START	;SETUP TO COMPARE STRINGS
		MOV	DI,SI
		MOV	CX,16		;16 BYTES MUST MATCH
		REP	CMPSB		;COMPARE DS:SI TO ES:DI
		OR	CX,CX		;DID THE STRINGS MATCH?
		JNE	NEXT_SEGMENT	;IF NO MATCH, TRY NEXT SEGMENT
		LEA	DX,INSTALLED_MSG
		JMP	SHORT ERR_EXIT
NOT_INSTALLED:
		MOV	AH,30H
		INT	21H		;GET DOS VERSION NUMBER
		CMP	AL,2		;IS IT HIGHER THAN 2.0?
		JNB	VER_OK		;IF YES, PROCEED
		LEA	DX,BAD_DOS_MSG
ERR_EXIT:	
		MOV	AH,9		;DOS DISPLAY STRING SERVICE
		INT	21H		;DISPLAY ERRER MESSAGE
		RET			;RETURN TO DOS
EXIT_NON_TSR:
		MOV	AH,4CH
		INT	21H
VER_OK:
		INC	SI		;POINT TO FIRST PARAMETER
		MOV	SI,81H		;POINT TO PARAMETER AREA
		CALL	GET_PARAM	;GET FIRST PARAMETER (ROWS)
		PUSH	AX		;SAVE THE ROW COUNT
		CALL	GET_PARAM	;GET SECOND PARAMETER (COLUMNS)
		ADD	AX,2		;ADD SPACE FOR CR AND LF
		POP	BX		;GET BACK FIRST PARAMETER
		MUL	BX		;PRODUCT OF ROWS AND COLUMNS
		OR	AX,AX		;WAS ANYTHING ENTERED?
		JE	NO_PARAMS	;IF NOT, USE DEFAULT VALUE
		CMP	AX,10000	;MAXIMUM BUFFER IS 10000 BYTES
		JLE	SIZE_IS_OK
		MOV	AX,10000
SIZE_IS_OK:
		ADD	AX,BUFF_START
		MOV	BUFF_END,AX	;SET THE NEW BUFFER SIZE
NO_PARAMS:
		MOV	AX,BIOS_SEG	;LOOK AT BIOS DATA AREA
		MOV	ES,AX
		ASSUME	ES:BIOS_SEG
		CMP	ROWS,0		;IS NUMBER OF ROWS ENTERED HERE
		JNE	MUST_BE_EGA	;IF YES, AN EGA MAY BE PRESENT
		MOV	ROWS,24		;IF NOT EGA, MUST BE 24 ROWS
MUST_BE_EGA:
		ASSUME	ES:NOTHING
           	MOV	AX,3509H	;GET KEYBOARD BREAK VECTOR
		INT	21H
		MOV	WORD PTR [OLDINT09],  BX  ;SAVE SEGMENT
		MOV	WORD PTR [OLDINT09+2],ES  ;SAVE OFFSET
		MOV	DX, OFFSET NEWINT09
		MOV	AX, 2509H
		INT	21H		;DOS FUNCTION TO CHANGE VECTOR
           	MOV	AX,3513H	;GET BIOS DISK INTERRUPT VECTOR
		INT	21H
		MOV	WORD PTR [OLDINT13],  BX  ;SAVE SEGMENT
		MOV	WORD PTR [OLDINT13+2],ES  ;SAVE OFFSET
		MOV	DX, OFFSET NEWINT13
		MOV	AX, 2513H
		INT	21H		;DOS FUNCTION TO CHANGE VECTOR
           	MOV	AX,3516H	;GET KEYBOARD INPUT VECTOR
		INT	21H
		MOV	WORD PTR [OLDINT16],  BX  ;SAVE SEGMENT
		MOV	WORD PTR [OLDINT16+2],ES  ;SAVE OFFSET
		MOV	DX, OFFSET NEWINT16
		MOV	AX, 2516H
		INT	21H		;DOS FUNCTION TO CHANGE VECTOR
           	MOV	AX,3521H	;GET DOS FUNCTION VECTOR
		INT	21H
		MOV	WORD PTR [OLDINT21],  BX
		MOV	WORD PTR [OLDINT21+2],ES
		MOV	DX, OFFSET NEWINT21
		MOV	AX, 2521H
		INT	21H		;DOS FUNCTION TO CHANGE VECTOR
		CALL	GET_PARAM
;--------------------------------------------------------------------;
; DEALLOCATE OUR COPY OF THE ENVIORNMENT.                            ;
; EXIT USING INT 27H. LEAVE CODE AND SPACE FOR BUFFER RESIDENT.      ;
;--------------------------------------------------------------------;
		MOV	AX,DS:[002CH]	;GET SEGMENT OF ENVIORNMENT
		MOV	ES,AX		;PUT IT INTO ES
		MOV	AH,49H		;RELEASE ALLOCATED MEMORY
		INT	21H
		MOV	DX,FILE_BUFF_END;LEAVE THIS MUCH RESIDENT
		INT	27H		;TEMINATE AND STAY RESIDENT
;---------------------------------------------------------;
; GET_PARAM RETRIEVES AN INTEGER FROM THE COMMAND LINE.   ;
;---------------------------------------------------------;
GET_PARAM:	
		XOR	AX,AX		;CLEAR AX FOR TOTAL
GET_DIGIT:	
		MOV	BL,[SI]		;GET CHARACTER INTO BL
		CMP	BL,0DH		;IS IT THE LAST ONE?
		JE	DONE
		INC	SI		;POINT TO NEXT CHARACTER
		CMP	BL,","		;IS IT THE DELIMITER?
		JE	DONE
		CMP	BL,"/"		;IS IT THE DELIMITER?
		JE	GET_THE_PATH
		SUB	BL,30H		;CONVERT ASCII TO INTEGER
		JB	GET_DIGIT	;IS IT A VALID DIGIT
		CMP	BL,9
		JA	GET_DIGIT	;IF NOT VALID, JUST SKIP IT
		MOV	BH,10		;TIMES 10 FOR NEXT DIGIT
		MUL	BH		;MULTIPLY SUM AND ADD THIS DIGIT
		ADD	AL,BL		;ADD DIGIT TO SUM
		JMP	GET_DIGIT	;READ ALL CHARACTERS ON LINE
GET_THE_PATH:
		MOV	BL,[SI]
		CMP	BL,50H
		JE	PATH_FLAG_OK
		CMP	BL,70H
		JNE	DONE
PATH_FLAG_OK:
		INC	SI
		MOV	BL,[SI]
		CMP	BL,3DH
		JNE	DONE
		INC	SI
		LEA	DI,FILE_PATH
GET_THE_PATH_LOOP:
		MOV	BL,[SI]
		CMP	BL,0DH
		JE	PATH_DONE
		MOV	[DI],BL
		INC	SI
		INC	DI
		JMP	GET_THE_PATH_LOOP
PATH_DONE:
		MOV	BYTE PTR[DI],5CH
DONE:		
		RET
CSEG		ENDS
		END	START