An operating system (OS) is
basically a program (usually: a set of programs) that mediates between
human users and the computer, and that can do most of the things most
programs that may run on the computer need: storing and retrieving from
disks or other media; handling user input; drawing to the screen; and
I have some experience with
six kinds of OS, namely in historical order CP/M, DOS, Apple, Windows,
Mac, Linux. All of these OSs had versions, often many, of which
generally the later ones were more capable than the earlier ones, and
for most there was a rather intimate relationship with a certain kind
of computer hardware.
There are more OSs, and
there have been considerably more, but currently most computer users
work with Windows, Mac or Linux.
CP/M I knew from an
Osborne computer produced in 1982 or 1983. It was an early OS for what
at the time was called "home computing", and is supposed to have been
rather well-designed. I can't say much about it, except that it did its
job on the Osborne quite well.
DOS - acronymic
speech for "Disk Operating System" - was (rapidly) designed for the IBM
PC and similar computers and was marketed very successfully by a small
software company called Microsoft, that had bought it from its
Both CP/M and DOS were
'character based' in the sense that they primarily dealt with the
screen as if it was made of series of rows of places on which one could
place one character. The reason was that personal computers around,
say, 1985 did not have enough processing speed and memory to do much
fancy processing with a screen made up of pixels.
Apple - I use this
name, somewhat imprecisely, for rectangular boxes with small graphical
black and white screens - I learned to use in the university in the
late eighties. They were in many ways, being graphical, more pleasant
to look at and work with than what DOS could do on a PC, but they were
also more expensive.
Windows I knew first
working under DOS, where it did produce a graphical environment like
that of Apple, except that it was much less powerful, quite slow, and
prone to crashes, for which reason I never did much with it on PCs
Mac is the name I use
for the follow-ups of the Apple I described above. I have some
experience with this, but not much.
Linux I have tried
quite a few times over the last 8 years. For various reasons - open
source, no Microsoft - it is better than Windows, but I have had little
luck with it and for the moment and the last years it is less fit for
my purposes (and health:
I don't have the health even if I had the inclinations to puzzle out
the arcana of Linux).
I am in principle much in
favour of Linux, but from what I've seen so far from it the developers
seem not to have been able as yet to lift it beyond an OS for techies.