Legacy apps in Windows/OS X was Re: Old MS-DOS & Win Software

[Teo Zenios]

----- Original Message ----- 
From: "Chuck Guzis" <cclist at sydex.com>
To: <cctalk at classiccmp.org>
Sent: Wednesday, December 07, 2005 8:26 PM
Subject: Re: Legacy apps in Windows/OS X was Re: Old MS-DOS & Win Software


> On 12/7/2005 at 6:32 PM Teo Zenios wrote:
>
> >I don't see the point of having so much legacy support in newer OS
> versions
> >(it is more complicated and has more code to create bugs). If there is a
> >need for such things then some company will develop a means of using your
> >older software via an emulator. Besides what is so hard about keeping a
> >legacy system in the house if you really need to run a 10 year old app on
> >occasion? OS developers should concentrate on making their OS stable and
> >reliable plus having good APIs, not in programming emulators and other
> >add-ons.
>
> ...and that's the point of Vista not having 16-bit support, I suppose.
> NT/2K/XP doesn't emulate 16 bit at the instruction level, it switches the
> processor to protected 16-bit operation and deals with interrupt vector
> mapping and other nonsense.  Heck, 16 bit doesn't run as fast as 32-bit or
> 64-bit mode on the X86 CPUs anyway--I've wondered for a long time why PCs
> still boot up in it.
>
> In an ironic sense of justice, MS has had to support most of the design
> mistakes it made in Windows 3.0 and MS-DOS by providing support for old
> applications.  Intel has had to live with the instruction set of the 8080
> all these years, only being allowed to extend it, but keeping things like
> the DAA instruction intact and supporting a bunch of do-nothing
> instructions like MOV DL,DL.
>

> Cheers,
> Chuck
>

I think Win2k server is the last MS OS that supports sharing directories
with old Mac AppleTalk networks. For my smallish network that OS will last
me a long time. So instead of complaining the latest and greatest doesn't
support my setup I just keep using what works.

Both Intel and MS didn't have to support their older designs, they did it
because the product worked and sold reasonable well, and any major change in
product that is incompatible with the older things you sold allows people to
chose what product they want to buy all over again (if you need new apps you
might as well consider a different OS/chip while changing). I think having a
major commercial success is what stops innovation at those companies, if you
have 5% market share you can pretty much try anything new since it will not
matter as much.