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 | Hardware Specification | 
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 | Table  | 
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 | Addresses | 
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 | Shared by All | 
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 | (in hex) | Size | Description | Processors? | Cacheable? | Comment | |
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 | 0000_0000h – | 640KB | Main memory | Yes | Yes | 
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 | 0009_FFFFh | 
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 | 000A_0000h – | 128KB | Display buffer for | Yes | No | 
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 | 000B_FFFFh | 
 | video adapters | 
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 | 000C_0000h – | 128KB ROM BIOS for  | Yes | Yes | 
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 | 000D_FFFFh | 
 | cards | 
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 | 000E_0000h – | 128KB | System ROM BIOS | Yes | Yes | 
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 | 000F_FFFFh | 
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 | 0010_0000h – | 
 | Main memory | Yes | Yes | Maximum address | |
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 | 0FEBF_FFFFh | 
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 | depends on total memory | |
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 | installed in the system. | 
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 | Not specified. | 
 | Yes2 | Not | Top unused memory | ||
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 | devices | 
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 | 0FEC0_0000h – | 
 | APIC I/O unit | Yes | No | Refer to the register | |
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 | 0FECF_FFFFh1 | 
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 | description in the APIC | |
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 | data book. | 
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 | 0FED0_0000h – | 
 | Reserved for | Yes2 | Not | 
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 | 0FEDF_FFFFh | 
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 | specified | 
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 | devices | 
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 | 0FEE0_0000h- | 
 | APIC Local Unit | No | No | Refer to the register | |
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 | 0FEEF_FFFFh1 | 
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 | description in the APIC | |
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 | data book. | 
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 | 0FEF0_0000h – | 
 | Reserved for | Yes2 | Not | 
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 | 0FFFD_FFFFh | 
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 | specified | 
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 | devices | 
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 | 0FFFE_0000h – | 128KB | Initialization ROM | Yes | Not | 
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 | 0FFFF_FFFFh | 
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 | specified | 
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NOTES:
1.These addresses are part of this specification. The other address regions in this table are shown for reference only, and should not be construed as the sole definition of a 
2.Any 
| Version 1.4 |