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Master the fundamental concepts of real mode programming through this focused micro-challenge.
Different segment:offset pairs can alias the same physical byte. 0000:7C00, 07C0:0000, and 7000:0C00 all map to 0x7C00. For example, a far jump to 0x0000:0x7C00 after loading a sector uses a different segment pair than the BIOS default 0000:7C00 but lands on identical physical memory.
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Watch wraparound: 0xFFFF:0x0010 becomes 0x00000 without A20.
Boot loaders often normalize CS to 0x0000 with IP=0x7C00 after a manual reload even though the BIOS entered at 07C0:0000. Understanding aliasing prevents off-by-16 bugs when mixing assembly modules assembled with different ORG assumptions. Label addresses in listings are offsets from ORG; always add the load address when reasoning about physical placement.
You will convert between segment:offset pairs and physical addresses in both directions. This exercise requires demonstrating overlapping segments and near/far pointer differences with concrete numeric examples.
Implement a segmented memory addressing simulator in C.
Requirements:
Test:
Three hints are available for this task, revealed one at a time inside the code workspace so you can struggle productively before seeing them.
Every task includes starter code, theory, and hidden tests so you can implement and verify locally in the browser.
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