Contiguous Allocation
 
 

The Bare Memory without an OS

Programs contain the code for device drivers
Compile time binding of addresses
 

OS + BIOS + Memory

IBM PCs
 

Overlays

Overlay drivers
user level management
 

Multiple Fixed Partitioning

Allocation: Single Queue Vs. Multiple Queues
The OS/360 scheme

Multiple Variable Partitioning

Allocation: first fit, best fit, worst fit

External and Internal Fragmentation