port to PDOS (especially mainframe)

[Paul Edwards]

On Saturday, April 17, 2021 at 2:37:23 PM UTC+10, Dan Stromberg wrote:

> > I want to produce EBCDIC executables that run on a 
> > S/3X0 (or z/Arch) machine (even if I personally do 
> > that via emulation). 
> >
> I thought EBCDIC was analogous to ASCII? 

EBCDIC is an alternative to ASCII. E.g. the character
'0' is at position x'F0' in EBCDIC compared to x'30'
in ASCII. Note that in EBCDIC, the letters 'A' to 'Z'
are not contiguous either, and the C90 standard has
been carefully worded and designed so that you can
rely on digits being contiguous, but not letters.

> Is it also analogous to a.out, ELF and COFF?

MVS 3.8J doesn't use any of those formats. The
executable format is just called "MVS load module".
And the object format is just called "object code".
I'm not aware of any special names for them.

PDOS/3X0 currently only runs MVS load modules,
but I have plans for a PDOS-generic which will run
under PDOS/3X0, and will use FAT instead of the
MVS file system (basically just a VTOC, equivalent
of a root directory, no subdirectories).

So the VTOC would have one important flat file which
PDOS-generic will access to provide a FAT facility to
any applications running under PDOS-generic. Those
applications will need to be specific to PDOS-generic
and they may well be a.out/ELF/COFF - I haven't
reached that point yet. I'm still preparing the assembler,
I can't do what I want without that. :-)

BFN. Paul.