1 | ; Project name : XTIDE Universal BIOS |
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2 | ; Description : Int 13h function AH=8h, Read Disk Drive Parameters. |
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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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8 | ; Int 13h function AH=8h, Read Disk Drive Parameters. |
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9 | ; |
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10 | ; AH8h_HandlerForReadDiskDriveParameters |
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11 | ; Parameters: |
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12 | ; DL: Translated Drive number |
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13 | ; DS:DI: Ptr to DPT (in RAMVARS segment) |
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14 | ; SS:BP: Ptr to IDEPACK |
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15 | ; Returns with INTPACK: |
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16 | ; BL: Drive Type (for floppies only) |
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17 | ; CH: Maximum cylinder number, bits 7...0 |
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18 | ; CL: Bits 7...6: Cylinder number bits 9...8 |
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19 | ; Bits 5...0: Maximum sector number (1...63) |
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20 | ; DH: Maximum head number (0...255) |
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21 | ; DL: Number of drives |
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22 | ; ES:DI: Floppy DPT (for floppies only) |
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23 | ; AH: Int 13h/40h floppy return status |
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24 | ; CF: 0 if successfull, 1 if error |
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25 | ;-------------------------------------------------------------------- |
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26 | AH8h_HandlerForReadDiskDriveParameters: |
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27 | test di,di |
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28 | jnz SHORT .OurDrive |
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29 | |
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30 | call Int13h_CallPreviousInt13hHandler |
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31 | jnc SHORT .MidGame |
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32 | jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH |
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33 | |
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34 | .OurDrive: |
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35 | call AH8h_GetDriveParameters |
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36 | |
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37 | %ifdef MODULE_SERIAL_FLOPPY |
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38 | push cs ; setup registers if we are a floppy drive, in all cases |
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39 | pop es ; if it is not a floppy drive, these values will not be put in INTPACK |
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40 | mov di, AH8h_FloppyDPT |
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41 | %endif |
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42 | ;; fall-through |
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43 | |
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44 | .MidGame: |
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45 | call RamVars_GetCountOfKnownDrivesToAX ; assume hard disk for now, will discard if for floppies |
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46 | |
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47 | test byte [bp+IDEPACK.intpack+INTPACK.dl], 080h |
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48 | jnz .Done |
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49 | |
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50 | mov [bp+IDEPACK.intpack+INTPACK.bl], bl |
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51 | |
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52 | mov [bp+IDEPACK.intpack+INTPACK.es], es |
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53 | mov [bp+IDEPACK.intpack+INTPACK.di], di |
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54 | |
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55 | call FloppyDrive_GetCountToAX |
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56 | |
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57 | .Done: |
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58 | mov ah, dh |
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59 | |
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60 | mov [bp+IDEPACK.intpack+INTPACK.cx], cx |
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61 | xchg [bp+IDEPACK.intpack+INTPACK.dx], ax ; recover DL for BDA last status byte determination |
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62 | |
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63 | xor ah, ah |
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64 | %ifdef MODULE_SERIAL_FLOPPY |
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65 | jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH_ALHasDriveNumber |
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66 | %else |
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67 | jmp Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH |
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68 | %endif |
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69 | |
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70 | |
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71 | ;-------------------------------------------------------------------- |
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72 | ; Returns L-CHS parameters for drive and total hard disk count. |
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73 | ; |
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74 | ; AH8h_GetDriveParameters |
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75 | ; Parameters: |
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76 | ; DS:DI: Ptr to DPT (in RAMVARS segment) |
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77 | ; Returns: |
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78 | ; CH: Maximum cylinder number, bits 7...0 |
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79 | ; CL: Bits 7...6: Cylinder number bits 9...8 |
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80 | ; Bits 5...0: Maximum sector number (1...63) |
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81 | ; DH: Maximum head number (0...255) |
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82 | ; Corrupts registers: |
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83 | ; AX, BX |
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84 | ;-------------------------------------------------------------------- |
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85 | AH8h_GetDriveParameters: |
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86 | call AccessDPT_GetLCHStoAXBLBH |
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87 | ; Fall to .PackReturnValues |
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88 | |
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89 | ;-------------------------------------------------------------------- |
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90 | ; Packs L-CHS values to INT 13h, AH=08h return values. |
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91 | ; |
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92 | ; .PackReturnValues |
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93 | ; Parameters: |
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94 | ; AX: Number of L-CHS cylinders available (1...1024) |
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95 | ; BL: Number of L-CHS heads (1...256) |
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96 | ; BH: Number of L-CHS sectors per track (1...63) |
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97 | ; DS: RAMVARS segment |
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98 | ; Returns: |
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99 | ; CH: Maximum cylinder number, bits 7...0 |
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100 | ; CL: Bits 7...6: Cylinder number bits 9...8 |
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101 | ; Bits 5...0: Maximum sector number (1...63) |
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102 | ; DH: Maximum head number (0...255) |
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103 | ; Corrupts registers: |
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104 | ; AX, BX |
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105 | ;-------------------------------------------------------------------- |
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106 | .PackReturnValues: |
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107 | dec ax ; AX = Number of last cylinder |
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108 | dec bx ; BL = Number of last head |
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109 | xchg cx, ax |
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110 | xchg cl, ch ; CH = Last cylinder bits 0...7 |
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111 | eROR_IM cl, 2 ; CL bits 6...7 = Last cylinder bits 8...9 |
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112 | or cl, bh ; CL bits 0...5 = Sectors per track |
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113 | mov dh, bl ; DH = Maximum head number |
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114 | |
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115 | %ifdef MODULE_SERIAL_FLOPPY |
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116 | mov bl,[di+DPT.bFlagsHigh] |
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117 | %ifndef CHECK_FOR_UNUSED_ENTRYPOINTS ; not sure why this is needed for preprocessor-only |
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118 | eSHR_IM bl,FLGH_DPT_SERIAL_FLOPPY_TYPE_FIELD_POSITION |
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119 | %endif |
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120 | %endif |
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121 | ret |
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122 | |
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123 | %ifdef MODULE_SERIAL_FLOPPY |
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124 | ; |
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125 | ; Floppy Disk Parameter Table. There is no way to specify more than one of these |
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126 | ; for any given system, so no way to make this drive or media specific. |
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127 | ; So we return fixed values out of the ROM for callers who might be expecting this information. |
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128 | ; |
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129 | ; On AT systems, we return the information for a 1.44 MB disk, |
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130 | ; and on XT systems, we return the information for a 360 KB disk. |
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131 | ; |
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132 | AH8h_FloppyDPT: |
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133 | %ifdef USE_AT |
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134 | db 0ah << 4 | 0fh ; Offset 0: Drive timings, 1.44MB values |
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135 | %else |
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136 | db 0dh << 4 | 0fh ; Offset 0: Drive timings, 360KB values |
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137 | %endif |
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138 | |
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139 | db 1h << 1 | 0 ; Offset 1: Typical values of 1 for head load time |
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140 | ; DMA used (although it actually is not, but is more restrctive) |
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141 | db 25h ; Offset 2: Inactiviy motor turn-off delay, |
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142 | ; Typical value of 25h for 2 second delay |
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143 | db 02h ; Offset 3: Sector size, always 512 |
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144 | |
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145 | %ifdef USE_AT |
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146 | db 12h ; Offset 4: Sectors per track, 1.44MB value |
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147 | db 1bh ; Offset 5: Sector gap, 1.44MB value |
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148 | %else |
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149 | db 09h ; Offset 4: Sectors per track, 360KB value |
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150 | db 2ah ; Offset 5: Sector gap, 360KB value |
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151 | %endif |
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152 | |
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153 | db 0ffh ; Offset 6: Data length |
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154 | |
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155 | %ifdef USE_AT |
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156 | db 6ch ; Offset 7: Format gap length, 1.44MB value |
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157 | %else |
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158 | db 50h ; Offset 7: Format gap length, 360KB value |
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159 | %endif |
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160 | |
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161 | db 0f6h ; Offset 8: Fill byte for format |
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162 | db 0fh ; Offset 9: Head setting time |
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163 | db 08h ; Offset A: Wait for motor startpu time |
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164 | |
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165 | %ifdef USE_AT |
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166 | db 79 ; Offset B: Maximum track number, 1.44MB value |
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167 | db 0 ; Offset C: Data transfer rate, 1.44MB value |
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168 | db 4 ; Offset D: Diskette CMOS drive type, 1.44MB value |
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169 | %else |
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170 | db 39 ; Offset B: Maximum track number, 360KB value |
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171 | db 80h ; Offset C: Data transfer rate, 360KB value |
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172 | db 1 ; Offset D: Diskette CMOS drive type, 360KB value |
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173 | %endif |
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174 | %endif |
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