With all the attention given to the personal computer, it's hard to remember that other companion machine in the room - the printer.

Multitasking, throughput, efficiency - these are excellent machine concepts, useful in the design of computer systems. But are they principles that nurture human thought and imagination?

Human thinking can skip over a great deal, leap over small misunderstandings, can contain ifs and buts in untroubled corners of the mind. But the machine has no corners. Despite all the attempts to see the computer as a brain, the machine has no foreground or background.

Computer programming has always been a self-taught, maverick occupation.

With code, what it means is what it does. It doesn't express, not really. It's a very bounded conversation. And writing is not bounded. That's what's hard about it.

The ability to 'multitask,' to switch rapidly among many competing focuses of attention, has become the hallmark of a successful citizen of the 21st century.