[102] | 1 | ; Project name : XTIDE Universal BIOS |
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[3] | 2 | ; Description : Various floppy drive related functions that |
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| 3 | ; Boot Menu uses. |
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| 4 | |
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[376] | 5 | ; |
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| 6 | ; XTIDE Universal BIOS and Associated Tools |
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| 7 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2012 by XTIDE Universal BIOS Team. |
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| 8 | ; |
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| 9 | ; This program is free software; you can redistribute it and/or modify |
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| 10 | ; it under the terms of the GNU General Public License as published by |
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| 11 | ; the Free Software Foundation; either version 2 of the License, or |
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| 12 | ; (at your option) any later version. |
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| 13 | ; |
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| 14 | ; This program is distributed in the hope that it will be useful, |
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| 15 | ; but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 16 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 17 | ; GNU General Public License for more details. |
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| 18 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html |
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| 19 | ; |
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| 20 | |
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[3] | 21 | ; Section containing code |
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| 22 | SECTION .text |
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| 23 | |
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| 24 | ;-------------------------------------------------------------------- |
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| 25 | ; Checks is floppy drive handler installed to interrupt vector 40h. |
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| 26 | ; |
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| 27 | ; FloppyDrive_IsInt40hInstalled |
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| 28 | ; Parameters: |
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| 29 | ; ES: BDA and Interrupt Vector segment (zero) |
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| 30 | ; Returns: |
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| 31 | ; CF: Set if INT 40h is installed |
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| 32 | ; Cleared if INT 40h is not installed |
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| 33 | ; Corrupts registers: |
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| 34 | ; BX, CX, DI |
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[86] | 35 | ;-------------------------------------------------------------------- |
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[3] | 36 | FloppyDrive_IsInt40hInstalled: |
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[152] | 37 | cmp WORD [es:BIOS_DISKETTE_INTERRUPT_40h*4+2], 0C000h ; Any ROM segment? |
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[102] | 38 | %ifdef USE_AT ; No need to verify on XT systems. |
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[39] | 39 | jb SHORT .Int40hHandlerIsNotInstalled |
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| 40 | call .VerifyInt40hHandlerSinceSomeBiosesSimplyReturnFromInt40h |
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[102] | 41 | .Int40hHandlerIsNotInstalled: |
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[99] | 42 | %endif |
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[27] | 43 | cmc |
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[3] | 44 | ret |
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| 45 | |
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[39] | 46 | ;-------------------------------------------------------------------- |
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| 47 | ; .VerifyInt40hHandlerSinceSomeBiosesSimplyReturnFromInt40h |
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| 48 | ; Parameters: |
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| 49 | ; Nothing |
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| 50 | ; Returns: |
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| 51 | ; CF: Cleared if INT 40h is installed |
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| 52 | ; Set if INT 40h is not installed |
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| 53 | ; Corrupts registers: |
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| 54 | ; BX, CX, DI |
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[86] | 55 | ;-------------------------------------------------------------------- |
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[99] | 56 | %ifdef USE_AT |
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[39] | 57 | .VerifyInt40hHandlerSinceSomeBiosesSimplyReturnFromInt40h: |
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| 58 | push es |
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| 59 | push dx |
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| 60 | push ax |
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[3] | 61 | |
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[39] | 62 | call .LoadInt40hVerifyParameters |
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[152] | 63 | int BIOS_DISK_INTERRUPT_13h |
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[99] | 64 | jc SHORT .Int40hIsInstalled ; Maybe there are not any floppy drives at all |
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| 65 | push es |
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| 66 | push di |
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[39] | 67 | |
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| 68 | call .LoadInt40hVerifyParameters |
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[152] | 69 | int BIOS_DISKETTE_INTERRUPT_40h |
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[39] | 70 | |
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| 71 | pop dx |
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| 72 | pop cx |
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| 73 | cmp dx, di ; Difference in offsets? |
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| 74 | jne SHORT .Int40hNotInstalled |
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| 75 | mov dx, es |
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| 76 | cmp cx, dx ; Difference in segments? |
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[99] | 77 | je SHORT .Int40hIsInstalled |
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[39] | 78 | .Int40hNotInstalled: |
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| 79 | stc |
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| 80 | .Int40hIsInstalled: |
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| 81 | pop ax |
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| 82 | pop dx |
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| 83 | pop es |
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| 84 | ret |
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| 85 | |
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[3] | 86 | ;-------------------------------------------------------------------- |
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[39] | 87 | ; .LoadInt40hVerifyParameters |
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| 88 | ; Parameters: |
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| 89 | ; Nothing |
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| 90 | ; Returns: |
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| 91 | ; AH: 08h (Get Drive Parameters) |
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| 92 | ; DL: 00h (floppy drive) |
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| 93 | ; ES:DI: 0:0h (to guard against BIOS bugs) |
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| 94 | ; Corrupts registers: |
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| 95 | ; DH |
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[86] | 96 | ;-------------------------------------------------------------------- |
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[39] | 97 | .LoadInt40hVerifyParameters: |
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[86] | 98 | mov ah, 08h ; Get Drive Parameters |
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| 99 | cwd ; Floppy drive 0 |
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[39] | 100 | mov di, dx |
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| 101 | mov es, dx ; ES:DI = 0000:0000h to guard against BIOS bugs |
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| 102 | ret |
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[99] | 103 | %endif |
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[39] | 104 | |
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| 105 | |
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| 106 | ;-------------------------------------------------------------------- |
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[3] | 107 | ; Returns floppy drive type. |
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| 108 | ; PC/XT system do not support AH=08h but FLOPPY_TYPE_525_OR_35_DD |
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| 109 | ; is still returned for them. |
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| 110 | ; |
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| 111 | ; FloppyDrive_GetType |
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| 112 | ; Parameters: |
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| 113 | ; DL: Floppy Drive number |
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| 114 | ; Returns: |
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| 115 | ; BX: Floppy Drive Type: |
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| 116 | ; FLOPPY_TYPE_525_OR_35_DD |
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| 117 | ; FLOPPY_TYPE_525_DD |
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| 118 | ; FLOPPY_TYPE_525_HD |
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| 119 | ; FLOPPY_TYPE_35_DD |
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| 120 | ; FLOPPY_TYPE_35_HD |
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| 121 | ; FLOPPY_TYPE_35_ED |
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| 122 | ; CF: Set if AH=08h not supported (XT systems) or error |
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| 123 | ; Cleared if type read correctly (AT systems) |
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| 124 | ; Corrupts registers: |
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| 125 | ; AX, CX, DX, DI, ES |
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| 126 | ;-------------------------------------------------------------------- |
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| 127 | FloppyDrive_GetType: |
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| 128 | mov ah, 08h ; Get Drive Parameters |
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| 129 | xor bx, bx ; FLOPPY_TYPE_525_OR_35_DD when function not supported |
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[152] | 130 | int BIOS_DISKETTE_INTERRUPT_40h |
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[3] | 131 | ret |
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| 132 | |
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| 133 | |
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| 134 | ;-------------------------------------------------------------------- |
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| 135 | ; Returns number of Floppy Drives in system. |
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| 136 | ; |
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[258] | 137 | ; FloppyDrive_GetCountToAX |
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[3] | 138 | ; Parameters: |
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[258] | 139 | ; DS: RAMVARS Segment |
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[3] | 140 | ; Returns: |
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[258] | 141 | ; AX: Number of Floppy Drives |
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[3] | 142 | ;-------------------------------------------------------------------- |
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[294] | 143 | FloppyDrive_GetCountToAX: |
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[258] | 144 | %ifdef MODULE_SERIAL_FLOPPY |
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| 145 | call RamVars_UnpackFlopCntAndFirstToAL |
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[270] | 146 | js .UseBIOSorBDA ; We didn't add in any drives, counts here are not valid |
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[294] | 147 | |
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| 148 | adc al,1 ; adds in the drive count bit, and adds 1 for count vs. 0-index, |
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[270] | 149 | jmp .FinishCalc ; need to clear AH on the way out, and add in minimum drive numbers |
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[258] | 150 | |
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[294] | 151 | .UseBIOSorBDA: |
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[99] | 152 | %endif |
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[258] | 153 | call FloppyDrive_GetCountFromBIOS_or_BDA |
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[270] | 154 | |
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[294] | 155 | .FinishCalc: |
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[258] | 156 | mov ah, [cs:ROMVARS.bMinFddCnt] |
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| 157 | MAX_U al, ah |
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| 158 | cbw |
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[294] | 159 | |
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[3] | 160 | ret |
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| 161 | |
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[258] | 162 | FloppyDrive_GetCountFromBIOS_or_BDA: |
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| 163 | push es |
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[3] | 164 | |
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| 165 | ;-------------------------------------------------------------------- |
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| 166 | ; Reads Floppy Drive Count from BIOS. |
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[294] | 167 | ; Does not work on most XT systems. Call .GetCountFromBDA |
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[3] | 168 | ; if this function fails. |
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| 169 | ; |
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[294] | 170 | ; .GetCountFromBIOS |
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[3] | 171 | ; Parameters: |
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| 172 | ; Nothing |
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| 173 | ; Returns: |
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[274] | 174 | ; AL: Number of Floppy Drives |
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[294] | 175 | ; CF: Cleared if successful |
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[3] | 176 | ; Set if BIOS function not supported |
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| 177 | ; Corrupts registers: |
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[274] | 178 | ; ES |
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[3] | 179 | ;-------------------------------------------------------------------- |
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[99] | 180 | %ifdef USE_AT |
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[258] | 181 | .GetCountFromBIOS: |
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[3] | 182 | push di |
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[274] | 183 | push bx |
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| 184 | push cx |
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[3] | 185 | push dx |
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| 186 | |
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| 187 | mov ah, 08h ; Get Drive Parameters |
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[86] | 188 | cwd ; Floppy Drive 00h |
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[152] | 189 | int BIOS_DISKETTE_INTERRUPT_40h |
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[258] | 190 | mov al, dl ; Number of Floppy Drives to AL |
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[3] | 191 | |
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[274] | 192 | pop dx |
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| 193 | pop cx |
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[3] | 194 | pop bx |
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| 195 | pop di |
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[99] | 196 | %endif |
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[3] | 197 | |
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| 198 | ;-------------------------------------------------------------------- |
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| 199 | ; Reads Floppy Drive Count (0...4) from BIOS Data Area. |
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[294] | 200 | ; This function should be used only if .GetCountFromBIOS fails. |
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[3] | 201 | ; |
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[294] | 202 | ; .GetCountFromBDA |
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[3] | 203 | ; Parameters: |
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| 204 | ; Nothing |
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| 205 | ; Returns: |
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[294] | 206 | ; AL: Number of Floppy Drives |
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[3] | 207 | ; Corrupts registers: |
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[294] | 208 | ; AH, ES |
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[3] | 209 | ;-------------------------------------------------------------------- |
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[99] | 210 | %ifndef USE_AT |
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[258] | 211 | .GetCountFromBDA: |
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| 212 | LOAD_BDA_SEGMENT_TO es, ax |
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| 213 | mov al, [es:BDA.wEquipment] ; Load Equipment WORD low byte |
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[294] | 214 | mov ah, al ; Copy it to AH |
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[258] | 215 | and ax, 0C001h ; Leave bits 15..14 and 0 |
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| 216 | eROL_IM ah, 2 ; EW low byte bits 7..6 to 1..0 |
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[294] | 217 | add al, ah ; AL = Floppy Drive count |
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[258] | 218 | %endif |
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| 219 | |
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| 220 | pop es |
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[3] | 221 | ret |
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