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| Low Memory (the first MiB) |
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| 0x00000000 | 0x000003FF | 1 KiB | RAM - partially unusable | Real Mode IVT |
| | | | | (Interrupt Vector Table) |
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| 0x00000400 | 0x000004FF | 256 bytes | RAM - partially unusable | BDA (BIOS data area) |
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| 0x00000500 | 0x00007BFF | almost 30 KiB | RAM (guaranteed free for use) | Conventional memory |
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| 0x00007C00 | 0x00007DFF | 512 bytes | RAM - partially unusable | Your OS BootSector |
| (typical location) | | | | |
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| 0x00007E00 | 0x0007FFFF | 480.5 KiB | RAM (guaranteed free for use) | Conventional memory |
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| 0x00080000 | 0x0009FBFF | approximately 120 KiB, | RAM (free for use, if it exists) | Conventional memory |
| | | depending on EBDA size | | |
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| 0x0009FC00 | 0x0009FFFF | 1 KiB | RAM (unusable) | EBDA (Extended BIOS |
| (typical location) | | | | Data Area) |
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| 0x000A0000 | 0x000FFFFF | 384 KiB | various (unusable) | Video memory, ROM Area |
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