Jerry Stuckle wrote:
I don't know, but my guess would be C. If you're familiar with the code
generated by the typical C compiler (back then there weren't as many
optimizations as today, so it should be easier), then a bit of
disassembly should give a pretty good idea if it is C or not.

Z80 assembler would also be a possibility, but it would be quite a bit
harder to code than a higher level language. Even though memory was
much less dense and more expensive back then, I think even C could be
used to generate the code. IIRC, the code for the TAPR TNC-2 was
written in C, for instance.

I remember coding for the Z80. To get the best performance out of it,
using assembly was really required. But of course it could be assembly
for the lowest levels and C for the higher level code.

As you write, it should be easy to see if a HLL was used or if it
is handcrafted assembly, just by looking at fragments of code.

There are also other options. In those days I coded a large program
for the Z80 using a couple of Aztec C products. There was a native
code generating compiler, and one that generated p-code for a machine
more suitable to execute C code. It existed only for the 6502
(and maybe for the 8080), but I wrote an efficient p-code interpreter
for the Z80.

The program consisted of a low level in assembly, some often used
functions in C compiled to native code, and the bulk of user interface
code in C compiled to p-code and interpreted. It was really amazing
how many lines of C could be crammed in 32K this way. Probably more
than when using assembly everywhere.