[fpc-devel] Episode 4. Addressing and it's limits Part Two

[Mark Morgan Lloyd]

rvmartin2 at ntlworld.com wrote:

>> In the current case I was relying on the precedent set by the GCC 
>> porters and the Linux maintainers to say "OK, we need to have some 
>> policy to determine what vintage of hardware is supported". However 
>> noting the availability of old IBM operating systems and the interest 
>> people have in running them, and in particular noting the amount of work 
>> being put into the OS/380 project, I'm fairly rapidly coming to the 
>> conclusion that the S/370 is worth supporting, even if we brush the 
>> S/360 under the carpet.
 >
 > To an application programmer there is (was?) little difference between
 > 360 and 370.
 >
 > I'm puzzled by this whole idea of Free Pascal supporting 360/370.
 > Who is it aimed at?  Who needs it?

Sorry Bob, I find that some of your postings aren't getting past our 
gateway, so I only see them in the archive.

To answer your question: I'm not entirely sure, but I suspect anybody 
who wants to run on any of the freely-available "classic" operating 
systems /particularly/ VM where the available version is VM/370 which 
could be expected to have problems if asked to support virtualised 
guests including S/390-specific opcodes.

My initial suggestion was to support anything from the S/390 G5 onwards, 
i.e. the same as Linux and (at least approximately) GCC. Paul's gone 
very quiet, Steve is making a fairly good case that there are sufficient 
well-understood workarounds that supporting S/370 if not S/360 should be 
possible, so I for one am happy to go with the flow on the target CPU 
(even if I express a strong preference for Linux and ASCII as the 
initial operating system targets).

-- 
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]