[52] | 1 | ; Project name : Assembly Library
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| 2 | ; Description : Functions for processing characters in a string.
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| 3 |
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| 4 | ; Section containing code
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| 5 | SECTION .text
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| 6 |
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| 7 | ;--------------------------------------------------------------------
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[67] | 8 | ; Character processing callback function prototype for StringProcess_DSSIwithFunctionInDX.
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[52] | 9 | ; Parameters:
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| 10 | ; AL: Character to process
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[67] | 11 | ; CX: Character number (index for next character)
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[52] | 12 | ; DS:SI: Ptr to next character
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| 13 | ; BX,DI,ES: Free to use by processing function
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| 14 | ; Returns:
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| 15 | ; CF: Clear to continue with next character
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| 16 | ; Set to stop processing
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| 17 | ; BX,DI,ES: Free to use by processing function
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| 18 | ; Corrupts registers:
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| 19 | ; AX
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| 20 | ;--------------------------------------------------------------------
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| 21 |
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| 22 |
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| 23 | ;--------------------------------------------------------------------
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| 24 | ; StringProcess_DSSIwithFunctionInDX
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| 25 | ; Parameters:
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| 26 | ; DX: Character processing function
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| 27 | ; DS:SI: Ptr to NULL terminated string to convert
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| 28 | ; Returns:
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| 29 | ; CX: Number of characters processed
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| 30 | ; CF: Clear if all characters processed
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[162] | 31 | ; Set if terminated by processing function
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[52] | 32 | ; Corrupts registers:
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| 33 | ; Nothing (processing function can corrupt BX,DI,ES)
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| 34 | ;--------------------------------------------------------------------
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[369] | 35 | ALIGN STRING_JUMP_ALIGN
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[52] | 36 | StringProcess_DSSIwithFunctionInDX:
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| 37 | push si
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| 38 | push ax
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| 39 |
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| 40 | xor cx, cx
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[369] | 41 | ALIGN STRING_JUMP_ALIGN
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[52] | 42 | .ProcessNextCharacter:
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| 43 | lodsb
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| 44 | test al, al ; NULL to end string
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| 45 | jz SHORT .EndOfString ; Return with CF cleared
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| 46 | inc cx
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| 47 | call dx
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| 48 | jnc SHORT .ProcessNextCharacter
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| 49 |
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[369] | 50 | ALIGN STRING_JUMP_ALIGN
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[52] | 51 | .EndOfString:
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| 52 | pop ax
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| 53 | pop si
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| 54 | ret
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| 55 |
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| 56 |
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| 57 | ;--------------------------------------------------------------------
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| 58 | ; StringProcess_ConvertToLowerCase (callback function for StringProcess_DSSIwithFunctionInDX)
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| 59 | ; Parameters:
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| 60 | ; AL: Character to convert to lower case
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| 61 | ; DS:SI: Ptr to next character
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| 62 | ; Returns:
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| 63 | ; CF: Clear to continue processing
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| 64 | ; Corrupts registers:
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| 65 | ; AL
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| 66 | ;--------------------------------------------------------------------
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[369] | 67 | ALIGN STRING_JUMP_ALIGN
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[52] | 68 | StringProcess_ConvertToLowerCase:
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| 69 | call Char_ALtoLowerCaseLetter
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| 70 | mov [si-1], al
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| 71 | clc
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| 72 | ret
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| 73 |
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| 74 |
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| 75 | ;--------------------------------------------------------------------
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| 76 | ; StringProcess_ConvertToWordInDIWithBaseInBX (callback function for StringProcess_DSSIwithFunctionInDX)
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| 77 | ; Parameters:
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| 78 | ; AL: Character to convert to lower case
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| 79 | ; BX: Numeric base (2, 10 or 16)
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| 80 | ; Returns:
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| 81 | ; CF: Clear to continue processing
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| 82 | ; Set if error
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| 83 | ; Corrupts registers:
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| 84 | ; AX
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| 85 | ;--------------------------------------------------------------------
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[369] | 86 | ALIGN STRING_JUMP_ALIGN
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[52] | 87 | StringProcess_ConvertToWordInDIWithBaseInBX:
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| 88 | call Char_ConvertIntegerToALfromDigitInALwithBaseInBX
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[162] | 89 | cmc
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| 90 | jc SHORT .InvalidCharacter
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[52] | 91 | push dx
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| 92 |
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| 93 | xor ah, ah ; Digit converted to integer now in AX
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| 94 | xchg ax, di
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| 95 | mul bx ; Old WORD *= base
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| 96 | jc SHORT .Overflow
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| 97 | add di, ax ; Add old WORD to new integer
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| 98 |
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| 99 | .Overflow:
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| 100 | pop dx
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| 101 | .InvalidCharacter:
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| 102 | ret
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