[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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[526] | 6 | ; XTIDE Universal BIOS and Associated Tools |
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| 7 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team. |
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[376] | 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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[526] | 13 | ; |
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[376] | 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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[526] | 17 | ; GNU General Public License for more details. |
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[376] | 18 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html |
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[526] | 19 | ; |
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[376] | 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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[524] | 24 | %ifdef COPY_13H_HANDLER_TO_40H |
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[3] | 25 | ;-------------------------------------------------------------------- |
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| 26 | ; Checks is floppy drive handler installed to interrupt vector 40h. |
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| 27 | ; |
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| 28 | ; FloppyDrive_IsInt40hInstalled |
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| 29 | ; Parameters: |
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| 30 | ; ES: BDA and Interrupt Vector segment (zero) |
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| 31 | ; Returns: |
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| 32 | ; CF: Set if INT 40h is installed |
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| 33 | ; Cleared if INT 40h is not installed |
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| 34 | ; Corrupts registers: |
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| 35 | ; BX, CX, DI |
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[86] | 36 | ;-------------------------------------------------------------------- |
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[3] | 37 | FloppyDrive_IsInt40hInstalled: |
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[152] | 38 | cmp WORD [es:BIOS_DISKETTE_INTERRUPT_40h*4+2], 0C000h ; Any ROM segment? |
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[102] | 39 | %ifdef USE_AT ; No need to verify on XT systems. |
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[39] | 40 | jb SHORT .Int40hHandlerIsNotInstalled |
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| 41 | call .VerifyInt40hHandlerSinceSomeBiosesSimplyReturnFromInt40h |
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[102] | 42 | .Int40hHandlerIsNotInstalled: |
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[99] | 43 | %endif |
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[27] | 44 | cmc |
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[3] | 45 | ret |
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| 46 | |
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[39] | 47 | ;-------------------------------------------------------------------- |
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| 48 | ; .VerifyInt40hHandlerSinceSomeBiosesSimplyReturnFromInt40h |
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| 49 | ; Parameters: |
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| 50 | ; Nothing |
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| 51 | ; Returns: |
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| 52 | ; CF: Cleared if INT 40h is installed |
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| 53 | ; Set if INT 40h is not installed |
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| 54 | ; Corrupts registers: |
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| 55 | ; BX, CX, DI |
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[86] | 56 | ;-------------------------------------------------------------------- |
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[99] | 57 | %ifdef USE_AT |
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[39] | 58 | .VerifyInt40hHandlerSinceSomeBiosesSimplyReturnFromInt40h: |
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| 59 | push es |
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| 60 | push dx |
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| 61 | push ax |
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[3] | 62 | |
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[39] | 63 | call .LoadInt40hVerifyParameters |
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[152] | 64 | int BIOS_DISK_INTERRUPT_13h |
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[99] | 65 | jc SHORT .Int40hIsInstalled ; Maybe there are not any floppy drives at all |
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| 66 | push es |
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| 67 | push di |
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[39] | 68 | |
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| 69 | call .LoadInt40hVerifyParameters |
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[152] | 70 | int BIOS_DISKETTE_INTERRUPT_40h |
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[39] | 71 | |
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| 72 | pop dx |
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| 73 | pop cx |
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| 74 | cmp dx, di ; Difference in offsets? |
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| 75 | jne SHORT .Int40hNotInstalled |
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| 76 | mov dx, es |
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| 77 | cmp cx, dx ; Difference in segments? |
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[99] | 78 | je SHORT .Int40hIsInstalled |
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[39] | 79 | .Int40hNotInstalled: |
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| 80 | stc |
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| 81 | .Int40hIsInstalled: |
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| 82 | pop ax |
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| 83 | pop dx |
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| 84 | pop es |
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| 85 | ret |
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| 86 | |
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[3] | 87 | ;-------------------------------------------------------------------- |
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[39] | 88 | ; .LoadInt40hVerifyParameters |
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| 89 | ; Parameters: |
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| 90 | ; Nothing |
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| 91 | ; Returns: |
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| 92 | ; AH: 08h (Get Drive Parameters) |
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| 93 | ; DL: 00h (floppy drive) |
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| 94 | ; ES:DI: 0:0h (to guard against BIOS bugs) |
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| 95 | ; Corrupts registers: |
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| 96 | ; DH |
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[86] | 97 | ;-------------------------------------------------------------------- |
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[39] | 98 | .LoadInt40hVerifyParameters: |
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[86] | 99 | mov ah, 08h ; Get Drive Parameters |
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| 100 | cwd ; Floppy drive 0 |
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[39] | 101 | mov di, dx |
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| 102 | mov es, dx ; ES:DI = 0000:0000h to guard against BIOS bugs |
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| 103 | ret |
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[99] | 104 | %endif |
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[39] | 105 | |
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[524] | 106 | %endif ; COPY_13H_HANDLER_TO_40H |
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[39] | 107 | |
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[524] | 108 | |
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[39] | 109 | ;-------------------------------------------------------------------- |
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[3] | 110 | ; Returns floppy drive type. |
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| 111 | ; PC/XT system do not support AH=08h but FLOPPY_TYPE_525_OR_35_DD |
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| 112 | ; is still returned for them. |
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| 113 | ; |
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| 114 | ; FloppyDrive_GetType |
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| 115 | ; Parameters: |
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| 116 | ; DL: Floppy Drive number |
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| 117 | ; Returns: |
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| 118 | ; BX: Floppy Drive Type: |
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| 119 | ; FLOPPY_TYPE_525_OR_35_DD |
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| 120 | ; FLOPPY_TYPE_525_DD |
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| 121 | ; FLOPPY_TYPE_525_HD |
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| 122 | ; FLOPPY_TYPE_35_DD |
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| 123 | ; FLOPPY_TYPE_35_HD |
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| 124 | ; FLOPPY_TYPE_35_ED |
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| 125 | ; CF: Set if AH=08h not supported (XT systems) or error |
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| 126 | ; Cleared if type read correctly (AT systems) |
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| 127 | ; Corrupts registers: |
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| 128 | ; AX, CX, DX, DI, ES |
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| 129 | ;-------------------------------------------------------------------- |
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[392] | 130 | %ifdef MODULE_BOOT_MENU |
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[3] | 131 | FloppyDrive_GetType: |
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| 132 | mov ah, 08h ; Get Drive Parameters |
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| 133 | xor bx, bx ; FLOPPY_TYPE_525_OR_35_DD when function not supported |
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[152] | 134 | int BIOS_DISKETTE_INTERRUPT_40h |
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[3] | 135 | ret |
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[392] | 136 | %endif |
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[3] | 137 | |
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| 138 | |
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| 139 | ;-------------------------------------------------------------------- |
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| 140 | ; Returns number of Floppy Drives in system. |
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| 141 | ; |
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[258] | 142 | ; FloppyDrive_GetCountToAX |
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[3] | 143 | ; Parameters: |
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[258] | 144 | ; DS: RAMVARS Segment |
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[3] | 145 | ; Returns: |
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[258] | 146 | ; AX: Number of Floppy Drives |
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[3] | 147 | ;-------------------------------------------------------------------- |
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[294] | 148 | FloppyDrive_GetCountToAX: |
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[258] | 149 | %ifdef MODULE_SERIAL_FLOPPY |
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| 150 | call RamVars_UnpackFlopCntAndFirstToAL |
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[270] | 151 | js .UseBIOSorBDA ; We didn't add in any drives, counts here are not valid |
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[294] | 152 | |
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| 153 | adc al,1 ; adds in the drive count bit, and adds 1 for count vs. 0-index, |
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[270] | 154 | jmp .FinishCalc ; need to clear AH on the way out, and add in minimum drive numbers |
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[258] | 155 | |
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[294] | 156 | .UseBIOSorBDA: |
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[99] | 157 | %endif |
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[258] | 158 | call FloppyDrive_GetCountFromBIOS_or_BDA |
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[270] | 159 | |
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[294] | 160 | .FinishCalc: |
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[258] | 161 | mov ah, [cs:ROMVARS.bMinFddCnt] |
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| 162 | MAX_U al, ah |
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| 163 | cbw |
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[294] | 164 | |
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[3] | 165 | ret |
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| 166 | |
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[258] | 167 | FloppyDrive_GetCountFromBIOS_or_BDA: |
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| 168 | push es |
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[3] | 169 | |
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| 170 | ;-------------------------------------------------------------------- |
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| 171 | ; Reads Floppy Drive Count from BIOS. |
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[294] | 172 | ; Does not work on most XT systems. Call .GetCountFromBDA |
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[3] | 173 | ; if this function fails. |
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| 174 | ; |
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[294] | 175 | ; .GetCountFromBIOS |
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[3] | 176 | ; Parameters: |
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| 177 | ; Nothing |
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| 178 | ; Returns: |
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[274] | 179 | ; AL: Number of Floppy Drives |
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[294] | 180 | ; CF: Cleared if successful |
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[3] | 181 | ; Set if BIOS function not supported |
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| 182 | ; Corrupts registers: |
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[274] | 183 | ; ES |
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[3] | 184 | ;-------------------------------------------------------------------- |
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[99] | 185 | %ifdef USE_AT |
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[258] | 186 | .GetCountFromBIOS: |
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[3] | 187 | push di |
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[274] | 188 | push bx |
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| 189 | push cx |
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[3] | 190 | push dx |
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| 191 | |
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| 192 | mov ah, 08h ; Get Drive Parameters |
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[86] | 193 | cwd ; Floppy Drive 00h |
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[152] | 194 | int BIOS_DISKETTE_INTERRUPT_40h |
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[258] | 195 | mov al, dl ; Number of Floppy Drives to AL |
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[3] | 196 | |
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[274] | 197 | pop dx |
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| 198 | pop cx |
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[3] | 199 | pop bx |
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| 200 | pop di |
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[99] | 201 | %endif |
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[3] | 202 | |
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| 203 | ;-------------------------------------------------------------------- |
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| 204 | ; Reads Floppy Drive Count (0...4) from BIOS Data Area. |
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[294] | 205 | ; This function should be used only if .GetCountFromBIOS fails. |
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[3] | 206 | ; |
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[294] | 207 | ; .GetCountFromBDA |
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[3] | 208 | ; Parameters: |
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| 209 | ; Nothing |
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| 210 | ; Returns: |
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[294] | 211 | ; AL: Number of Floppy Drives |
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[3] | 212 | ; Corrupts registers: |
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[294] | 213 | ; AH, ES |
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[3] | 214 | ;-------------------------------------------------------------------- |
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[99] | 215 | %ifndef USE_AT |
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[258] | 216 | .GetCountFromBDA: |
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| 217 | LOAD_BDA_SEGMENT_TO es, ax |
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| 218 | mov al, [es:BDA.wEquipment] ; Load Equipment WORD low byte |
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[294] | 219 | mov ah, al ; Copy it to AH |
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[258] | 220 | and ax, 0C001h ; Leave bits 15..14 and 0 |
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| 221 | eROL_IM ah, 2 ; EW low byte bits 7..6 to 1..0 |
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[294] | 222 | add al, ah ; AL = Floppy Drive count |
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[258] | 223 | %endif |
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| 224 | |
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| 225 | pop es |
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[3] | 226 | ret |
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