JWasm: Masm Compatible Assembler

Back from the dead? Old‑school coder tool sparks fork wars

TLDR: JWasm, a classic low-level coding tool, appears active again and still runs on everything from Windows to old DOS boxes. The community’s torn between cheering the comeback and defending popular forks ASMC and UASM, debating whether to reunite under JWasm or stick with the successors that kept development going.

JWasm, a Microsoft‑style assembler for writing ultra low‑level code, just shuffled back into the spotlight—and the retro crowd is buzzing. One commenter summed up the plot twist: development stalled, two forks—asmc and UASM—took over, and now it looks alive again. That’s all it took for the thread to crackle with “who should we back now?” energy.

Fans are gawking at the throwback vibes: JWasm runs on Windows and Linux, sure, but also DOS and OS/2—with notes about even building a limited 16‑bit version for ancient 8088‑era machines. Cue the “my grandpa’s PC just got an update” jokes and some spicy nostalgia. Others are eyeing the practical stuff: there’s a manual, makefiles for different compilers, and a path for Visual C++ or Open Watcom—translation: it’s not just a museum piece.

But here’s the drama: fork loyalty. Some are waving the ASMC or UASM flags—they kept the lights on during JWasm’s quiet years—while curiosity grows around JWasm’s apparent return. Is this a heroic comeback, or a “too little, too late” reboot? The mood swings between “welcome home, legend” and “pick a lane, people”. Either way, the retro‑hardware memes are flowing, the terminal warriors are sharpening their macros, and the assembler soap opera just got a new season.

Key Points

  • JWasm is a MASM-compatible assembler that runs on Windows, Linux, DOS, and OS/2.
  • Windows builds use Msvc.mak/Msvc64.mak with Visual C++ or OWWin32.mak with Open Watcom.
  • Linux builds use GccUnix.mak with GCC or CLUnix.mak with Clang.
  • DOS builds are supported via Open Watcom, including a limited 16-bit version for 8088 CPUs; older Visual C++ may work with HX development files.
  • An OS/2 build is supported via OWOS2.mak, and additional makefiles exist for other compilers, some possibly outdated.

Hottest takes

"A few years ago, I think JWasm development halted" — anta40
"and eventually came 2 forks" — anta40
"Now seems like JWasm is under development ..." — anta40
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