Discussion prompt
20 minutes. Think of a device you use daily. In 150 to 200 words, say what is held in its memory and what is held in its storage when you are using it, and what you would lose if the power failed without warning.
Private: nothing you type here is sent or stored.
This course has no discussion board yet, so the prompt is a private reflection.
Recap
- Processor, memory, storage and devices have separate jobs; memory is temporary and storage is long term.
- Convert to a single unit before dividing; decimal prefixes step by 1,000.
- The processor repeats fetch, decode, execute; STORE copies the accumulator to memory.
- The operating system shares the processor, manages memory and files and applies permissions.
Module notes
Key terms. Processor: carries out instructions. Memory (RAM): temporary working space. Storage: long-term keeping. Accumulator: the working register of the toy machine. Process: a program being run. Operating system: the program that manages resources.
Rules and formulas. 1 byte = 8 bits. 1 KB = 1,000 bytes; 1 MB = 1,000 KB; 1 GB = 1,000 MB (decimal). Files that fit = storage size ÷ file size, in the same unit. Time between turns = programs × turn length.
Limits of this module. This module uses a simplified picture of hardware and an invented toy machine. Real figures for speed and size change with each device and are not stated here.
Next
Continue to Module 8: Networks, Security and the Limits of Computing. You can also return to the course overview or the University Track.
References and further reading
- Specialty Digest encyclopedia: Computer, Alan Turing and Programming Language.
- The fetch, decode and execute cycle and the roles of memory, storage and the operating system are standard computing textbook material.
- The toy machine, its instructions, time-slice lengths and file sizes in this module are invented for teaching and labelled as such.