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Assembly Source File | 1989-06-10 | 21.8 KB | 427 lines

;------------------------------------------------------; ; Convert.com - Converts either a number or character ; ; to complementary radices. ; ; Decimal, Hexadecimal, Octal and Binary supported. ; ; PC Magazine * Michael J. Mefford ; ;------------------------------------------------------; _TEXT SEGMENT PUBLIC 'CODE' ASSUME CS:_TEXT,DS:_TEXT,ES:_TEXT,SS:_TEXT ORG 100H START: JMP MAIN ; DATA AREA ; --------- SYNTAX DB CR,SPACE,SPACE,SPACE,CR,LF COPYRIGHT DB "CONVERT 1.0 (C) 1989 Ziff Communications Co.",CR,LF PROGRAMMER DB "PC Magazine ",BOX," Michael J. Mefford",CR,LF,LF DB "Syntax: CONVERT number[-number][radix] | " DB QUOTES,"character(s)",QUOTES,CR,LF DB "radix: b = binary, h = hexadecimal, o = octal",CR,LF DB "default is decimal",LF,"$",CTRL_Z CR EQU 13 LF EQU 10 CTRL_Z EQU 26 SPACE EQU 32 QUOTES EQU 34 BOX EQU 254 SPACE_CNT EQU 5 INVALID_MSG DB "Invalid parameter",CR,LF DB "number range: 0 - 65535",CR,LF,"$" RADIX_TYPE DB "HOB" ;Hex, octal, binary. RADIX_CNT EQU $ - RADIX_TYPE INPUT_CALLS DW DECIMAL_INPUT, HEX_INPUT, OCTAL_INPUT, BINARY_INPUT CALLS_END EQU $ - 2 ; CODE AREA ; --------- ;------------------------------------------------------------------------; ; Capitalize the parameters so a single compare for radices can be done. ; ;------------------------------------------------------------------------; MAIN PROC NEAR CLD ;All string moves forward. CMP BYTE PTR DS:[80H],0 ;Are there parameters? JNZ PARSE ;If yes, continue. JMP ERROR_EXIT ;Else, exit with syntax message. ;------------------------------------------------------------------------------; ; Parse the parameters by looking for either carriage return, quotes, or dash. ; ;------------------------------------------------------------------------------; PARSE: MOV DL,LF ;Print a linefeed just to first CALL PRINT_CHAR ; to make our output look pretty. MOV SI,82H ;Point to parameters again. NEXT_INPUT: MOV BP,SI ;Start parameter start. NEXT_PARSE: LODSB ;Get a byte. CMP AL,CR ;Is it carriage return? JZ EVALUATE ;If yes, done here. CMP AL,QUOTES ;Is it quotes? JZ CHARACTER ;If yes, character entry. CMP AL,"-" ;Is it delimiting dash? JNZ NEXT_PARSE ;If no, find parameter end. CMP BP,82H ;Else, is this first dash? JNZ EVALUATE ;If no, evaluate just the two. PUSH SI ;Save our position. CALL GET_NUMBER ;Get the parameter. POP SI ;Restore our position. PUSH BX ;Save the number. JMP SHORT NEXT_INPUT ;Get second parameter. ;----------------------------------------------------------------------; ; If quotes were detected, store up to two characters to be evaluated. ; ;----------------------------------------------------------------------; CHARACTER: XOR BX,BX ;Assume no characters. LODSB ;Get a byte. CMP AL,CR ;End of parameter? JZ ERROR_EXIT ;If yes, no character; exit. MOV BL,AL ;Else, store character. LODSB ;Get next character. CMP AL,CR ;End of parameter? JZ GOT_CHAR ;If yes, only one character. CMP AL,QUOTES ;Is it quotes? JNZ GET_CHAR ;If no, valid second character. CMP BYTE PTR [SI],QUOTES ;Is it followed by quotes? JNZ GOT_CHAR ;If no, not quotes in quotes. GET_CHAR: MOV BH,AL ;Else, store second character. XCHG BH,BL ;Swap so in right order. GOT_CHAR: XOR CX,CX ;Zero out parameter count. JMP SHORT CONVERT ;Convert the character. ;-------------------------------------------------------------; ; Find range of numbers and display the complementry radices. ; ;-------------------------------------------------------------; EVALUATE: CALL GET_NUMBER ;Get the parameter. XOR CX,CX ;Assume only one parameter. CMP BP,82H ;Where there more than one? JZ CONVERT ;If no, convert just the one. POP CX ;Else, retrieve the first one. CMP CX,BX ;Is it the larger of the two? JA FIND_RANGE ;If yes, find range. XCHG BX,CX ;Else, swap numbers. FIND_RANGE: SUB CX,BX ;Find difference. CONVERT: INC CX ;Increment by one for "thru". MOV DI,BX ;Save number to be converted. OUTPUT: PUSH CX ;Save count to be converted. CALL DECIMAL_OUTPUT ;Display decimal, hexadecimal, CALL SPACE_IT ; octal and binary equivalents CALL HEX_OUTPUT ; with spaces in between. CALL SPACING CALL OCTAL_OUTPUT CALL SPACING CALL BINARY_OUTPUT CALL SPACING CALL ASCII_OUTPUT MOV DL,CR CALL PRINT_CHAR MOV DL,LF CALL PRINT_CHAR INC DI ;Get ready for next number. POP CX ;Retrieve conversion count. LOOP OUTPUT ;Do them all. XOR AL,AL ;Exit with ErrorLevel of zero. JMP SHORT EXIT ;---------------------------------------------------------------------------; ; Exit with syntax message and ErrorLevel of 1 if error, else ErrorLevel 0. ; ;---------------------------------------------------------------------------; ERROR_EXIT: MOV DX,OFFSET SYNTAX ;Display syntax. CALL PRINT_STRING MOV AL,1 ;ErrorLevel one. EXIT: MOV AH,4CH INT 21H ;Terminate. MAIN ENDP ; ************* ; *SUBROUTINES* ; ************* ;------------------------------------------------------------------------------; ; INPUT: SI points to byte after parameter end; BP points to parameter start. ; ; OUTPUT: BX = number. ; ; CALLS: DECIMAL_INPUT, HEX_INPUT, OCTAL_INPUT, BINARY_INPUT. ; ;------------------------------------------------------------------------------; GET_NUMBER PROC NEAR DEC SI ;Adjust pointer to parameter end. MOV CX,SI ;Save SI. MOV SI,BP ;Point to parameter start. NEXT_CAP: CMP SI,CX ;Are we end of parameter? JZ STRING_LENGTH ;If yes, done here. LODSB ;Get a byte. CMP AL,"a" JB NEXT_CAP CMP AL,"z" JA NEXT_CAP AND BYTE PTR [SI-1],5FH ;Capitalize. JMP SHORT NEXT_CAP STRING_LENGTH: MOV SI,BP ;Point to parameter start. SUB CX,BP ;Find parameter length. PUSH CX ;Save it. NEXT_RADIX: XCHG CX,BX ;Save count in BX. LODSB ;Get a byte. MOV CX,RADIX_CNT ;Count of radix appendixes in CX. MOV DI,OFFSET RADIX_TYPE ;Point to appendixes. REPNZ SCASB ;Is it an appendix? JZ INPUT ;If yes, evaluate. XCHG CX,BX ;Else, retrieve parameter count. LOOP_RADIX: LOOP NEXT_RADIX ;Check next byte. MOV CX,RADIX_CNT ;If no appendix, assume decimal. INPUT: SHL CX,1 ;Convert count to word pointer. MOV DI,OFFSET CALLS_END ;Point to input calls end. SUB DI,CX ;Point to appropriate call. POP CX ;Retrieve parameter length. MOV SI,BP ;Point to parameter start. XOR BX,BX ;Start with a zero number. CALL [DI] ;Get the number. MOV DX,OFFSET INVALID_MSG ;Print error message if JNC END_NUMBER ; number invalid. CALL PRINT_STRING JMP SHORT ERROR_EXIT END_NUMBER: RET ;Else, return with number in BX. GET_NUMBER ENDP ;----------------------------------------------------------------------; ; INPUT: SI points to parameter start; CX = parameter length; BX = 0. ; ; OUTPUT: BX = number; CY = 0 if valid entry; CY = 1 if invalid entry. ; ;----------------------------------------------------------------------; DECIMAL_INPUT PROC NEAR NEXT_DECIMAL: LODSB ;Get a character. SUB AL,"0" ;ASCII to binary. JC LOOP_DECIMAL ;If not between 0 and 9, skip. CMP AL,9 JA LOOP_DECIMAL CBW ;Convert to word. XCHG AX,BX ;Swap old and new number. PUSH CX ;Preserve counter. MOV CX,10 ;Shift to left by multiplying MUL CX ; last entry by ten. POP CX ;Retrieve counter. JC END_DECIMAL ;If carry, too big. ADD BX,AX ;Add new number and store in BX. JC END_DECIMAL ;If carry, too big. LOOP_DECIMAL: LOOP NEXT_DECIMAL CLC END_DECIMAL: RET DECIMAL_INPUT ENDP ;-----------------------------------------------------------------------; ; INPUT : SI points to parameter start; CX = parameter length; BX = 0. ; ; OUTPUT : BX = number; CY = 0 if valid entry; CY = 1 if invalid entry. ; ;-----------------------------------------------------------------------; BINARY_INPUT PROC NEAR NEXT_BIN: LODSB ;Get a byte. SUB AL,"0" ;ASCII to binary. JC LOOP_BIN ;If not 0 or 1, skip. CMP AL,1 JA LOOP_BIN SHL BX,1 ;Shift old number left one bit. JC END_BIN ;If carry, too big. OR BL,AL ;Else, add it to the number. LOOP_BIN: LOOP NEXT_BIN CLC END_BIN: RET BINARY_INPUT ENDP ;-----------------------------------------------------------------------; ; INPUT : SI points to parameter start; CX = parameter length; BX = 0. ; ; OUTPUT : BX = number; CY = 0 if valid entry; CY = 1 if invalid entry. ; ;-----------------------------------------------------------------------; HEX_INPUT PROC NEAR NEXT_HEX: LODSB ;Get a byte. SUB AL,"0" ;ASCII to binary. JC LOOP_HEX ;If not 0 to 9, skip. CMP AL,9 ;Is it A - F ? JLE NOT_ALPHA ;If no, OK. SUB AL,7 ;Else, adjust for alpha. CMP AL,10 ;Is it punctuation? JB LOOP_HEX ;If yes, skip. CMP AL,15 ;Is it valid? JA LOOP_HEX ;If no, skip. NOT_ALPHA: TEST BX,1111b SHL 12 ;Is the number going to overflow? STC ;Assume yes. JNZ END_HEX ;If yes, too big. PUSH CX ;Else, preserve counter. MOV CL,4 ;Shift old number four bits left. SHL BX,CL POP CX ;Retrieve counter. OR BL,AL ;Add to number. LOOP_HEX: LOOP NEXT_HEX CLC END_HEX: RET HEX_INPUT ENDP ;-----------------------------------------------------------------------; ; INPUT : SI points to parameter start; CX = parameter length; BX = 0. ; ; OUTPUT : BX = number; CY = 0 if valid entry; CY = 1 if invalid entry. ; ;-----------------------------------------------------------------------; OCTAL_INPUT PROC NEAR NEXT_OCTAL: LODSB ;Get a byte. SUB AL,"0" ;ASCII to binary. JC LOOP_OCTAL ;If not 0 through 7, skip. CMP AL,7 JA LOOP_OCTAL TEST BX,111b SHL 13 ;Is the number going to overflow? STC ;Assume yes. JNZ END_OCTAL ;If yes, too big. PUSH CX ;Else, save counter. MOV CL,3 ;Shift old number left three bits SHL BX,CL POP CX ;Retrieve counter. OR BL,AL ;Add to number. LOOP_OCTAL: LOOP NEXT_OCTAL CLC END_OCTAL: RET OCTAL_INPUT ENDP ;-----------------------------------------------------------------------; ; INPUT : SI points to parameter start; CX = parameter length; BX = 0. ; ; OUTPUT : BX = number; CY = 0 if valid entry; CY = 1 if invalid entry. ; ;-----------------------------------------------------------------------; DECIMAL_OUTPUT PROC NEAR MOV AX,DI ;Retrieve number. MOV BX,10 ;Divisor of ten. XOR CX,CX ;Zero in counter. NEXT_COUNT: XOR DX,DX ;Zero in high half. DIV BX ;Divide by ten. ADD DL,"0" ;Convert to ASCII. PUSH DX ;Save results. INC CX ;Also increment count. CMP AX,0 ;Are we done? JNZ NEXT_COUNT ;Continue until zero. MOV BX,CX ;Save the number of characters. NEXT_NUMBER: POP DX ;Retrieve numbers. CALL PRINT_CHAR ;And write them. LOOP NEXT_NUMBER MOV CX,SPACE_CNT + 5 ;Return with tab count. SUB CX,BX RET DECIMAL_OUTPUT ENDP ;----------------------------------------; ; INPUT: DI = number. ; ;----------------------------------------; HEX_OUTPUT PROC NEAR MOV BX,DI ;Retrieve number. MOV CX,404H ;4 positions/word; 4bits/char. ROTATE_HEX: ROL BX,CL ;Move highest bits to lowest. MOV DL,BL AND DL,1111B ;Mask off all but four lowest. ADD DL,"0" ;Convert to ASCII. CMP DL,"9" ;Is it alpha. JLE PRINT_HEX ;If no, print it. ADD DL,7 ;Else, adjust. PRINT_HEX: CALL PRINT_CHAR ;And write them. DEC CH ;Done all four positions? JNZ ROTATE_HEX ;If no, get next. MOV DL,"h" ;Tack on hex character. CALL PRINT_CHAR RET HEX_OUTPUT ENDP ;----------------------------------------; ; INPUT: DI = number. ; ;----------------------------------------; OCTAL_OUTPUT PROC NEAR MOV BX,DI ;Retrieve number. MOV CX,603H ;6 positions/word; 3bits/char. ROL BX,1 ;Special case first; get top bit. MOV DL,BL AND DL,1 ;Mask off all but that bit. JMP SHORT OCTAL_ASCII ;Write it. OCTAL_ROTATE: ROL BX,CL ;Rotate highest 3 bits to lowest. MOV DL,BL AND DL,111B ;Mask off all but lowest 3 bits. OCTAL_ASCII: ADD DL,"0" ;Convert to ASCII. CALL PRINT_CHAR ;Write it. DEC CH ;Do all 6 positions. JNZ OCTAL_ROTATE MOV DL,"o" ;Tack on octal character. CALL PRINT_CHAR RET OCTAL_OUTPUT ENDP ;----------------------------------------; ; INPUT: DI = number. ; ;----------------------------------------; BINARY_OUTPUT PROC NEAR MOV BX,DI ;Retrieve number. MOV CH,16 ;Display all 16 positions. ROTATE_BIN: ROL BX,1 ;Move highest bit to lowest. MOV DL,BL AND DL,1 ;Mask off all but lowest. ADD DL,"0" ;Convert to ASCII. CALL PRINT_CHAR CMP CH,9 ;Format with space between bytes. JNZ SKIP_SPACE MOV DL,SPACE CALL PRINT_CHAR SKIP_SPACE: DEC CH ;Do all 16 bits. JNZ ROTATE_BIN MOV DL,"b" ;Tack on binary character. CALL PRINT_CHAR RET BINARY_OUTPUT ENDP ;----------------------------------------; ; INPUT: DI = number. ; ;----------------------------------------; ASCII_OUTPUT PROC NEAR XOR BH,BH ;Page zero. MOV AX,0E22H ;Write TTY a quote mark. INT 10H ; via BIOS. MOV CX,3 ;Display 3 quotation marks and MOV AX,0A22H ; do not update cursor position. INT 10H MOV CX,2 ;Display the low byte twice MOV AX,DI MOV AH,0AH ; at current cursor position. INT 10H MOV CX,1 ;Display the high byte once MOV AX,DI ; at current cursor position XCHG AL,AH MOV AH,0AH ; over the first low byte. INT 10H RET ASCII_OUTPUT ENDP ;---------------------------------------------------------------; ; These subroutines print and separate the display with spaces. ; ;---------------------------------------------------------------; PRINT_CHAR PROC NEAR MOV AH,2 ;DOS display output. INT 21H ;Character is in DL. RET PRINT_CHAR ENDP ;-------------------------; PRINT_STRING PROC NEAR MOV AH,9 ;DOS string output. INT 21H ;DX points to string RET ; terminated by "$". PRINT_STRING ENDP ;-------------------------; SPACING PROC NEAR MOV CX,SPACE_CNT ;Retrieve space count between SPACE_IT: MOV DL,SPACE ; outputs and print via DOS. CALL PRINT_CHAR LOOP SPACE_IT RET SPACING ENDP _TEXT ENDS END START