I'm looking for the most recent versions of modern C compilers which were/are targeting DOS 8086, also running on DOS 8086 (16-bit). I'm mostly interested in production-ready C compilers, rather than hobby projects (possibly many bugs yet to be discovered).
By modern I mean:
- support for ANSI C (C89) source files
- support for generating small model and large model DOS
See in my answer what I've found to work.
I'm aware of the following C compilers, but they are not answers to my question, because they have some required features missing:
LSI C-86 3.30c released on 1993-08-23: It doesn't support the large memory model.
DeSmet C 3.1h (1988) and DeSmet C 3.1N (1992): It seems to support ANSI C and the large memory model. (Compile hello.c using the small model:
bind hello. Compile hello.c using the large model:
c88 hello b;
bbind hello) But it doesn't support the unsigned long type. Also I wasn't able to define a function which takes variable number of arguments (
va_list args;doesn't compile). Also compilation breaks in weird ways, e.g.
foo->field = 42;doesn't compile (but
(*foo).field = 42;does), but then in the next line it compiles. I've given up on this compiler, it has too many bugs.
PCC 1.2d: It has the same engine as DeSmet C 2.51. It doesn't support the large memory model.
HI-TECH Software Pacific C 7.51 released on 1996-01-20 (and re-released with a less restrictive license on 2000-05-10): (1) the compiler is generating some useless overflow warnings for numbers between -40 and 40, so there may be many code generation bugs, probably not worth the effort; (2) the compiler is running out of memory for my tools which Borland Turbo C++ 1.01, Borland C++ 2.0 and Microsoft C 6.00a can compile easily. I've given up on it.
Manx Software Systems Aztec C86 5.2a released on 1992-11-17. It isn't able to compile my tools, the assembler fails with out-of-memory error. Borland C++, Microsoft C and Zortech C++ are all able to compile the program successfully. Also with the
-ansiflag it displays some weird error messages (all other modern and all the mentioned old C compilers succeed), I'm not sure how easy it is to work around the errors. It does support the small and large models.
I'm aware of the following C compilers, but they are not answers to my question, because they don't run on DOS 8086:
OpenWatcom. I've successfully compiled C code targeting DOS 8086 with the most recent build 2022-11-22 on DOSBox with 5 MiB of memory. Arguably OpenWatcom is the most modern C/C++ compiler still targeting DOS 8086. However, the DOS port of the compiler itself runs in 32-bit protected mode, and thus needs a 386 processor. I'm not using the DOS port though, the native ports to my laptop are faster, and they produce the same DOS program.
Microsoft Visual C++
Borland C++ Builder
Digital Mars C/C++ 8.57 released on 2022-05-14: The compiler
.exefiles are for Win32, they don't run on DOS 8086.
Smaller C 1.0.1 released on 2021-09-14: Even the DOS real mode compiler tools (e.g.
bind/smlrc.exe) need a 386 CPU.
Symantec C/C++. This is the successor of Zortech C++, and the compiler executable programs probably run in protected mode, thus they need a 386 CPU. Maybe version 6.0 still contains DOS 8086 programs, I have to try. In version 6.1 there is the
sc -b ...command-line flag, but the corresponding
scc.exe(C compiler for DOS 8086) and
scpp.exe(C++ compiler for DOS 8086) are not provided, probably they were never released. The protected mode programs
scppx.exerun in protected mode, and need a 386 CPU (they work in DOSBox with 2 MiB of memory). Release history:
- Symantec C++ Professional 6.0 was released in 1993-09.
- Symantec C++ Professional 6.1 was released in 1993-12.
- Symantec C++ 7.0 for Windows was released in 1995-07.
- Symantec C++ 7.2 for Windows 95, Windows NT 3.5, Windows 3.1 and DOS was released in 1995-10.
- Symantec C++ 7.50 was released in 1997.
Is there any C compiler I've missed? Maybe there is a much more recent (than 1992) minimalistic C compiler.