[geeks] Oldest OS Still Developed

[Charles Shannon Hendrix]

Wed, 18 Oct 2006 @ 20:10 +0200, Geoffrey S. Mendelson said:

> On Wed, Oct 18, 2006 at 01:56:06PM -0400, Charles Shannon Hendrix wrote:
> > 	- UNIX
> 
> Late 1970's.

No, early 1970s.  It was all in C by 1972 or so.

> > 	- MVS
> 
> Early to mid 1960's 

No, it was not released until 1974.

> > 	- DOS/VE (I *think* it is still developed)
> 
> I think it post dates OS/360 from which MVS derives, but I am not sure.
> By 1969 you had TOS (which I think was no longer supported), DOS, OS/360,
> ACP and VM/360.

DOS/VSE (*) is 41 years old this year, so that puts it at 1965.

* I think this is the right name, not DOS/VE, unless both were used.

> OS/360 still lives on as MVS, VM is still around, but most of it migrated
> to hardware in the late 1980s. I don't know if anyone still uses ACP, 
> and I have never seen a TOS system, but I have been using 360's (and on)
> since the late 1960s.

IBM just recently made DOS/VSE (z/VSE) a 64-bit OS. They acknowledge it
won't actually help much since most VSE programs are 24-bit, but it does
allow z systems to run them in 64-bit address spaces.

The next version of DOS/VSE will require a 64-bit machine, which will
end-of-life support for 31-bit systems that are still running.

IBM must hold the record for how long they'll support a system.

> > 	- PSOS
> > 	- OS/9
> 
> Don't know about those.

Embedded system OS that have been around for at least 20 years.

> > 	- RT/11
> 
> PDP-11s? New hardware my friend. :-) Weren't they the first machines to use
> that silly reversed byte order?

RT/11 is an old OS now, but I believe some clone PDP-11 systems still
use it.

Seems like it qualifies to me.

> > All of those are still used, and the last two I think might even still
> > be maintained since they are still used in embedded systems and PDP
> > clones.
> > 
> > Do the space shuttle computers have any kind of OS?
> 
> So? 

So they are pretty old now. They are based on the IBM 360 mainframe. I
just checked and could not find anything about an OS. The software is
written in HAL/S, but there was no information about how task switching
and other functions are performed.

> OS/360 was used by theMercury program, the shuttle is another new
> system. The shuttle's computers were so bad that the astronauts were
> carrying Grid Laptop PCs on flights.

They used a laptop because they needed a general purpose computer, not
because of anything wrong with the shuttle computers.

The shuttle computers are narrow purpose embedded systems and were never
designed to perform the functions of a laptop.

-- 
shannon "AT" widomaker.com -- ["There are nowadays professors of
philosophy, but not philosophers." ]