Today I added source code of classic public domain assembler zmac to nedoPC SDK repo (it's used by SDK to build Zilog Z80 code):

https://gitlab.com/nedopc/sdk/-/tree/master/zmac?ref_type=heads

It was added in a few commits to show what was changed in 2005 by our forum user Vasil Ivanov:

v1.32: https://gitlab.com/nedopc/sdk/-/commit/ce00665e44cff00515c33e000170bccb87784d62

v1.33: https://gitlab.com/nedopc/sdk/-/commit/f2f4a71a8acf64f28210d868ac1258743c205014

Vasil worked directly inside of generated zmac.c, so now we don't use zmac.y to build it - and that's way it could be built even for DOS by OpenWatcom-C/C++ v1.9 for example:

SET WATCOM=C:\SYSTEM\WATCOM19
SET PATH=%WATCOM%\BINW
SET INCLUDE=%WATCOM%\H
WCC386 /onatx /oh /ei /3 /fp3 getoptn.c
WCC386 /onatx /oh /ei /3 /fp3 mio.c
WCC386 /onatx /oh /ei /3 /fp3 zmac.c
WLINK system pmodew option stack=32k file getoptn,mio,zmac name zmac

Changes from 2005 on top of classic public domain version from 2000:

2005-03-30  Vasil Ivanov from http://forum.nedopc.org
        * Version 1.33 -- changes were done directly in generated zmac.c
        * All messages stderr now go to stdout to be able to redirect everything to 1 file
        * Fixed issue in new function doincbin() that caused "phase error".

2005-02-25  Vasil Ivanov from http://forum.nedopc.org
        * Version 1.32 -- changes were done directly in generated zmac.c
        * Put all labels starting with @ to file .tbl
        * Added directive INCBIN to include binary file
        * Note: Quotation is not needed for include and incbin
        * Note: This assembler doesn't know undocumented instructions

Now I'm working on new command interpreter to have unified build script covering multiple platforms at once...