The z88dk focus is supporting z80 ish based systems, mainly. There is “new” library support for
support for all its hardware.
Compiler support is achieved through the sccz80 (which is managed in-house and can react quickly to issues). For example when Alan commented that sccz80 blew up on
Fuzix, these issues were fixed quickly. Still to be verified.
The sdcc is also used because it generates "better" code in most cases, but as a compiler it is slow. There is a patch used to provide connection to z88dk library routines, and one or two other issues. Fixing sdcc issues is a bit slower, because it is not managed by z88dk team, but still Philippe at sdcc tends to get things done in batches, when his attention is on the z80 back end.
Others focus hardware in new library is the
ZX Spectrum Next with its special instructions and
copper video coprocessor. That is taking a lot of focus for some contributors. All Spectrum Next graphics options are supported.
In the classic library there are crt0, graphics, sound, keyboards for
almost all classic systems. I think one new old system is added every month. If you’ve got an old z80 system in the shed, chances are it’s already supported, or it can be added quickly. Issue challenge by adding an issue to github.
The actual supported cpus are z80, z180, and z80-zxn. I hesitate to call them 1st class processors. But that is essentially the case. There's enough open things do in just the z80 system (and binary compatible) world, without trying to do everything.
Z280 is being added to the assembler , but is not finished.
ez80 has been added to sccz80 already too. the sdcc compiler already supports ez80, and
ez80 is included (actually not excluded) in the default compile of zsdcc (the patch of sdcc used).
8080 has an awk translation tool that is pretty good. I used it for LLL floating point code. Only one or two mis-translation issues.
Cheers Phillip