[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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| 35 | ALIGN JUMP_ALIGN |
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| 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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| 41 | ALIGN JUMP_ALIGN |
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| 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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| 50 | ALIGN JUMP_ALIGN |
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| 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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| 67 | ALIGN JUMP_ALIGN |
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| 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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| 86 | ALIGN JUMP_ALIGN |
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| 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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