This page was last modified 13:46, 26 January 2021 by Ped7g. Based on work by Manuel and Gdx and others.

Project page:

Spin off of SjAsm with many extensions and bug fixes. It is a cross-platform assembler for the Z80/R800/Z80N/i8080/LR35902 processors. An executable is available for Windows 32bit, build instructions for Linux/Mac/FreeBSD are included (GNU-make and CMake supported) (x86/x86_64/arm/arm64/... any modern little-endian platform with linux or BSD and C++14 compiler should work, and since v1.18.1 also big-endian platforms are supported, although the support is only "experimental" level).

Main features:

  • Full source of assembler available under BSD license, modify and extend as you wish
  • Z80/R800/Z80N/i8080/LR35902 documented and undocumented opcodes support
  • 3-pass design
  • Macro language, defines, array of defines
  • Built-in Lua scripting engine
  • Conditional assembly, block repeating
  • Modules (namespaces), local and temporary labels
  • Source and binary file inclusion, include paths
  • Multi file output, file updating, various types of exports
  • Structures to work easily with structured data in memory (STRUCT pseudo-op)
  • Relocation data generator to support SymbOS-like relocation of executables
  • Virtual device mode for common machines: ZX 128, ZX Next, … (pseudo op DEVICE)
  • ZX Spectrum specific directives and pseudo ops (SAVESNA, SAVETAP, SAVEHOB, INCHOB, INCTRD…)
  • ZX Spectrum Next specific features and directives (Z80N, 8ki memory paging, SAVENEX)
  • Correctness is assured by Cirrus-CI with 380+ automated tests (that's also 380+ examples of usage!)
  • Fake instructions as LD HL,DE (LD H,D:LD L,E) and more
  • Code inlining through colon (LD A,C:INC A:PUSH AF:IFDEF FX:LD A,D:ENDIF…)
  • Very fast compilation: 1 million lines by 2-3 seconds on modern computer
  • Multiline block comments and user’s messages

Latest release available at:

Original project old homepage:

There is also one more spin off of original project at: