Re: Why are Ada compilers difficult to write ?

["Randy Brukardt" <randy@rrsoftware.com>]

There's no particular problem in supporting a Z80 cross-compiler, we just 
haven't had anyone asking about it in decades. I'd be concerned about 
getting the old runtime up to modern specifications, but otherwise I don't 
think it would be too hard. (Not sure if I could find the source to the old 
code cruncher, which doubled the amount of code one could run on that 
processor.)

                                  Randy.

"Dan'l Miller" <optikos@verizon.net> wrote in message 
news:8e8e7ce9-d7ac-4ec5-8278-7b93cec46599@googlegroups.com...
On Thursday, June 21, 2018 at 10:44:21 PM UTC-5, Paul Rubin wrote:
> "Dan'l Miller" <optikos@verizon.net> writes:
> > Which Ada complier(s) support any of... Zilog's Z80
>
> http://www.z80.eu/ADA.html mentions a few.  Found in 2 sec by typing
> "z80 ada" into web search.  You could try the same with the other cpus
> you mentioned.  I'm guessing it's Ada-83 or some subset, but that's a
> start.

Writing a compiler in OP refers to both writing it from scratch as well as 
maintenance over the years.  All of the Ada compilers listed on that 
antiquated page are in various stages of broken links, out of business, and 
no longer supporting Z80 in recent .decades..

After performing a fair amount of searching on both Bing and Google, I could 
not find any Ada compiler targeting Z80 other than ancient archives of 
CP/M-era Ada compilers from the 1980s for ancient OSes.  The only hope for a 
still-in-operation vendor of a still-maintained-for-a-fee Ada compiler for 
Z80 would be RR Software's old Janus Ada for CP/M.  Apparently, it is either 
technically difficult and/or financially cost-prohibitive to support Ada for 
resource-constrained* targets in the 8080/Z80, 6809, and 6502 families, 
which have been repurposed as 8-bit microcontrollers (notwithstanding AVR's 
novel usage of "8-bit microcontroller" to refer to a modern RISC processor 
that has 32 registers many of which are 16-, 24-, or 32-bit in size)

* e.g., 64 KiB DRAM address space; clock rate of single-digit or tens of 
megahertz

Various ports of GCC to Z80 exist, but they seem to focus exclusively on 
C-proper, instead of on C++ or Ada.