suborb

The zx81 uses one of the index registers for display generation and sdcc may well end up using both of them as part of the codegen with the default options....

@dbolli zx81 runs with `--IXIY` which swaps the index registers at assembly time. This does makes for a bit of head scratching at times but does work. I guess there's...

It looks like rel2z80 outputs a very old .obj file version. I think handling .rel files is on @pauloscustodio list of features for z80asm

I think `-Cz-o [filename]` might do it. We notably don't have any explicit support for the CPC+ models unfortunately.

I think that's the eternal internal quandary regarding label lookup - at the moment it deliberately doesn't match const values, only address types. If you change the `SYM_ADDRESS` to `SYM_ANY`...

I think this was originally by design to allow people to override configuration. However, I suspect that people aren't actually doing that so I'll comment out that bit out and...

There's a few ways of doing this at the moment: 1. Create a separate library the contains only the OS specific code and supply that library on the SUBTYPE line...

I suspect a little reorg might become necessary. These little libraries shouldn't be "targets" in the true sense, so don't belong in the top level makefile, but probably ought to...

I've added some makefile gunk in branch `feature/1568_newlib_linklibs` to scan `target/${TARGET}/library/` for extra lst files. We can have extra library files for: - sccz80 `target/zx/library/zxfoo_sccz80.lst` creates `lib/sccz80/zxfoo_sccz80.lib` - sdcc_ix `target/zx/library/zxfoo_sdcc_ix.lst`...

For c99+ compliance we need to support: >A 0x or 0X prefix, then a sequence of hexadecimal digits (as in [isxdigit](https://www.cplusplus.com/isxdigit)) optionally containing a period which separates the whole and...