In article >,
Krypsis > wrote:

> DOS 5.0 was a "Disk Operating System", not an "Operating System" as that

No, it's an operating system, one based on disks rather than the
previous standard, which was magnetic tapes. When I got my first job
programming, we had a disk based OS, but all the commands were backward
compatible to tapes. After you got done looking at a file, the file
pointer was at the end. If you tried to look at the file again, there
was nothing left to see. There were a lot of panic attacks. "My file
is gone!". No, it was just fine. You needed to issue a REWIND command
to move the file pointer back to the beginning. This made a lot of
sense for tape files, since you often stored multiple files on a tape,
and sometimes you wanted to access them sequentially. It takes
comparatively long to rewind a tape file, so it wasn't done
automatically.

> would assume control over a bit more than disk drives and various bits
> of hardware. There wasn't even a hint of security in DOS (input any
> version), a feature vital in a multiuser/multitasking environment.

The computer used physical security. You locked it in a room, and no
one could access it. That's all you needed. And there was no multiuser
or multitasking. There was no network connection. At best, there was a
dialup modem, which was never left connected. You *always* disconnected
when not using it. And if you forgot, generally you got disconnected
automatically after a short time of no traffic (10 minutes for my ISP
from home).

--
Dan Abel
Petaluma, California USA