What is the opposite of "multitasking?"

"Multitasking" is a commonly-used word in computer science and has a lay meaning as well. What is the opposite of "multitasking?"

I tried "unitasking" in a recently letter to a colleague and was met with mock horror. Perhaps "singletasking" or "single-tasking" is more natural? Or another word altogether?

[EDIT]
I need the antonym in a computer science document, and "non-multitasking" is quite stilted. concentrating would have a very low probability of being correctly construed by my reader to mean "one task at a time".

Solution 1:

Single-tasking is by far the most common, and I would argue the most correct in the tech world -- you will find many, many references to it in technical documents. For example:

As this was a single-tasking OS, "switching between applications" meant copying data from the first application to the clipboard, then exiting the application, starting another, and pasting. MiniFinder was intended to streamline this process. (Wikipedia entry on Mac OS Finder)

or

A control system emulates a multi-tasking environment using a single tasking processor. (Xerox patent from 1975)

or a more popular tech culture reference:

Researchers Give Up Google and Discover Single Tasking (a Technoverse article from 2010)

Solution 2:

Besides single-tasking, sequential processing, serial processing, sequential tasking, serial tasking, or single threading might also work. Here's a comparison:

_{N.B. Multiprocessing might, depending on your context, be different from multitasking.}

A chap named Joel Spolsky uses sequential processing as a contrast to multitasking (on CPUs):

But look at Computation A. With multitasking, its results take 19 seconds to arrive...yet with sequential processing they are ready in only 10 seconds. In other words, in this nice contrived example, the average time per computation is lower (15 seconds rather than 19.5 seconds) when you do sequential processing rather than multitasking.

There are a number of other instances of similar usage.

Solution 3:

In some contexts, the term dedication may be useful.

the quality of being dedicated or committed to a task or purpose

It can be used as a noun.

I want dedication to this task! No more distractions

It has the benefit of a comfortable adjective and verb form.

The kids stopped multitasking and were dedicated to their homework.
The programmers dedicated the CPU to number crunching instead of managing the peripherals.
It was taken offline and became a dedicated printer, only used by the boss.