Overview

The Evolution of Memory Management traces how operating systems transitioned from simple contiguous physical memory allocation to flexible hardware-assisted virtual memory paradigms, solving issues of memory fragmentation, access protection, and dynamic process sizing.


Translation Paradigm Comparison

ParadigmAllocation UnitHardware RegistersPrimary Fragmentation Issue
Base & BoundSingle contiguous chunk per processBase Register, Bound RegisterExternal Fragmentation
SegmentationVariable-sized logical segments (Code, Data, Stack)Segment Table (Base + Bound per segment)External Fragmentation
PagingFixed-size pages / frames (e.g., 4 KB)Page Table Base Register (PTBR)Internal Fragmentation (last page only)

Module Notes