Re: Why are Ada compilers difficult to write ?

["Dan'l Miller" <optikos@verizon.net>]

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.