On Wed, Nov 07, 2007 at 04:48:04PM -0800, Fred Cisin wrote:
On Wed, 7 Nov 2007, ajones wrote:
There was never a version of Linux, or UNIX in
general, less bloated
than Windows 95.
Xenix ran on an 8088 XT with 640K. The IBM XT hard disk controller could
be jumpered (undocumented) to handle other sizes of drives other than the
412 (10MB). One of those sizes was 26MB, which was just right for a 10MB
DOS partition and a 16MB Xenix partition (that was how I found out about
the XT hard disk controller's undocumented jumper solder pads)
[1] Yes, Windows 95 had memory protection and
preemptive multitasking.
Are there multiple definitions of "preemptive"?
Or, is "preemptive" a quantitative, rather than qualitative attribute?
I would not consider Win95, nor early Mac, to be "preemptive".
Old MacOS (before MacOS X) was cooperative multitasking. As was 16 bit
Windows. Not sure about Windows95, but I guess at best it was probably a
nasty mixed bag.
Even NT4,
which is purportedly preemptive has a few two many situations where/when
it can not be preempted. For example, when opening a telnet session, it
often can NOT be preempted until it gets to the point of success or failure.
The last time I had to touch NT4 is almost a year ago, but I do not
remember the system grinding to a stop when opening a telnet connection.
'Can not be preempted' means 'no other process gets to run' - and I have
a very hard time believing that to be the case for establishing a TCP
connection. My personal impression of NT (in part formed by having to
program IPC related stuff against the Win32 API) was that deep down, NT
is a pretty decent OS, it just got bogged down by stupid ideas tacked on
later and buried under a mountain of crap piled on by Microsofts less
talented hacks. I'm talking about the kernel, not the userland, mind
you - because the user environment is a total desaster in my personal
opinion (which admittedly is shaded heavily by being a unix zealot who
basically considers X to be a pretty nice environment to run plenty of
xterms in).
The basic kernel level design looks pretty good and caused quite a sense
of dejavu for me[0] - no surprise when one considers who did the original
design. And I distinctly remember the scheduler to be preemptive.
(Yes, there were plenty of silly ideas later - like moving the GUI code
into kernel mode for speeds sake ... *sigh*).
Regards,
Alex.
[0] Heaving read up on VMS internals only months before.
--
"Opportunity is missed by most people because it is dressed in overalls and
looks like work." -- Thomas A. Edison