Memory

Having looked at peripherals which tend not to be integrated with the processor, it is now time to look at memory, which is integrated.

A difference between a PC and a mainframe is a question of scale. A PCs memory tends to be measured in Gigabytes. The largest IBM z15 T01 mainframe supports up to 40 Terabytes (TBs) of memory.

Whilst virtual storage and paging operations do occur on a PC, they are not obvious to the user, unlike on a mainframe.

Addressability is another difference. On a PC the latest jump was from 32 to 64-bit addressing, but for compatibility reasons the mainframe supports three types of addressing; 24-bit, 31-bit and 64-bit.

Mainframe Introduction

Peripherals - (Input / Output Devices)
- Disks, Cartridges, etc
Memory
Processors
- Processor Resource/Systems Management (PR/SM)
Operating Systems
Mainframe and the Cloud