Re: backward architecture, The Design of Design

On Thu, 9 May 2024 08:19:39 -0000 (UTC)
Thomas Koenig <tkoenig@netcologne.de> wrote:

Michael S <already5chosen@yahoo.com> schrieb:
 

Can you, please, define the meaning of upward and downward
compatibility? I had never seen this terms before this thread, so
it is possible that I don't understand the meaning. 

 
The term comes from Brooks.  Specifically, he applied it to the
S/360 line of computers which had a very wide performance and
price range, and programs (including operating systems) were
binary compatible from the lowest to the highest performance and
price machine.

I suppose, it means that my old home PC (Core-i5 3550) is downward
compatible with my old work PC (Core-i7 3770). And my old work PC is
upward compatible with my old home PC.

But I still don't know if it would be correct to say that my old work
PC is downward compatible with with my just a little newer small FOGA
development server (E3 1271 v3). My guess that it would be incorrect,
but it's just guess.

If Brook was still alive, we could have tried to ask him. But since he
is not, and since I have no plans to read his books by myself, my only
chance of knowing is for you or for John Levine to find  the definition
it in his writings and then tell me.