Hi,

I remember back in 2012 (I think) there was a large discussion about implementing support for the zSeries IBM mainframes. The wiki had many pages on the topic too.

http://wiki.freepascal.org/ZSeries

Anybody know what actually happened with those efforts? Was there something usable in the end?

On a side note:
Some of you might enjoy this video. I really can see the appeal he has for vintage hardware.

"Here's what happens when an 18 year old buys a mainframe". https://youtu.be/45X4VP8CGtk

Regards,
Graeme

There was a lot of discussion that boiled down to five things:

* Should the compiler (as distinct from the generated code) use EBCDIC and what effect did this have on collation order assumptions?

* Older members of the range used a proprietary floating-point format.

* Older members of the range didn't have dedicated stack operations and were restricted to a 12-bit relative addressing offset.

* Allowing for the unrestricted availability of 1980s operating systems that were restricted to the above, what should the target of an FPC implementation be?

* What assembler would be supported, allowing that IBM system software long described interfaces in terms of assembler macros?

One developer- who put a lot in the wiki- appeared to grind to a halt when he realised that it wasn't possible to generate a static cross-reference listing for the FPC compiler, due to the number of runtime decisions made based on the class of elements in the parse tree etc.

If I may express two personal opinions:

* My preferred target hardware would be the oldest that got stack and large-offset support, which was also where GCC started taking it fairly seriously. I believe there is at least one GCC port that targets older hardware (Paul Edwards?).

* My preferred target operating system would be VM/380, which is VM/370 with what is effectively a DOS extender to allow it to compile programs that require >16 MegaOctets. My basis for this preference is that its lineage (Multics etc.) makes it pleasingly familiar to people used to PC-DOS and unix, I've been criticised by somebody who would prefer MVS on the basis that the interface macros are different but I consider this to be a detail since the code generation would probably be common.

Bernd Oppolzer is actively maintaining a derivative of the original "P" compiler on VM/370 http://bernd-oppolzer.de/job9.htm and I expect this to be bundled with the next release of the VM/370 "Sixpack" http://www.smrcc.org.uk/members/g4ugm/vm-370/VM370sixpack-1_3-Beta.zip which will run on top of the Hercules emulator. I can't remember whether he was able to compile it using FPC, there were some string-expansion issues (relating to mainframes using fixed-length records) giving him problems.

Gotta go, venison's done :-)