3.3.3 Discuss the characteristics of various computer systems including
single users and multi-users, in both single-tasking and multi-tasking
environments.
Teaching Note:
The terms multi-access and multi programming should be
understood but details of the way in which they are managed will not
be examined.
JSR Notes:
There are three full pages of notes in the text book on this. Note that the assessment statement is quite general: compare characteristics of various computer systems. "Systems" in this case can mean broader collections of hardware and computers, or it can be just individual computers - as you'll see described in the text book. But highlighted in the syllabus are single/multi-user, and single/multi-task.
PCs in the olden days could only single-task. You'd run one application or another. So in a way single vs. multitasking is yet another antiquated part of the syllabus. But remember that this is a broad assessment statement, not just one about personal computers per se. There are still many, many, many computer systems all around us which single process; in fact just about all of the billions of dedicated microprocessors in electronic goods can be classified as single-tasking computer systems. A clothes washer microprocessor, for example only looks after temperature, time and spinning revolutions of a certain pre-programmed washing cycle; it does not at the same time check the weather for drying conditions, and continually monitor prices of clothes detergent at various grocery stores, and allow playing of mine-sweeper or solitaire, while you're waiting for the washing cycle to finish...though it could...
Meantime, yes, now-a-days all PCs are indeed quite capable of multi-processing, just like your calculators, I guess... my how times have changed.
More important for you to remember from 3.3.3 is that there exist multi-user systems that are outside of your realm of experience. These are systems that connect many "dumb terminals" to a "mainframe computer/server". The applications are run from the mainframe, on the terminals. As long as the mainframe and network are robust enough, there does not have to be a speed or memory reduction doing things this way, and it makes the maintenance of large multi-user environments infinitely more manageable than the "lab" approach like we use at ISP and most schools, for example.
In the teaching notes, we can assume that "multi programming" is the same as "multi-tasking", and that "multi-access" is associated with multi-user systems.
The text goes on, in 3.3.3, to describe in some detail the characteristics of various computer systems. Note that a lot of this really belongs in 3.3.4