DDLab for DOS, and DOSBox, readme:  September 2023 update
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This executable is ddz11dos.exe, compiled in Windows 7, 32 bit
available at
http://www.ddlab.org/download/ddlab_compiled_Sept2023/ and mirror sites.

ddlabz11_dos32.tar.gz unpacks to give
ddz11dos.exe, dos4gw.exe, seriff.fon, smallf.fon (and GNU_GPL_3.txt)
put these 4 files in a directory, for example \watcom\ddlabz11\
(the dirirectory and file names must be max 8 chrs or less
before extension, the DOS convention)

In older versions of Windows, run in a DOS or terminal window.
In  windows 7 and later, run in DOSBox

To run DDLab in DOSbox in Windows 7 (or later):
* double-click the DOSBox icon.
* a DOSBox window appears with Z:\>
  enter "mount c \watcom\ddlabz11" 
  Z:\>mount c \watcom\ddlabz11
* if mounted ok, shows ...
  "Driver C is mounted as a local directory \watcom\ddlabx11\
* then enter "c:"
  Z:\>c: (which changes Z:\> to C:\>)
  C:\>dir (will list the files: ddz10dos.exe dos4gw.exe seriff.fon small.fon)
* to run ddlab: enter the file name "ddz11dos"
  C:\DDLab>ddz11dos (or 'ddz11dos -w' for a white background)

The default low-resolution 640x480 is recommended, where the cursor is
visible/active and confined inside DOSBox.
(In medium or high resolution the cursor is invisible though
still in the background)

To exit DOSbox, first exit ddlab, then C\:exit

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DOSBox can also run in Linux (as a check)
(https://help.ubuntu.com/community/DOSBox)

* In a regular terminal (i.e /home/user, not DOSBox)
* enter "mkdir -p ~/dos/c" to create the /dos/c directory in your home directory. 
* enter "cd ~/dos/c" to change directory, giving ...:/dos/c$
  (then "ls" to check contents, ddz11dos.exe dos4gw.exe,
  seriff.fon smallf.fon should be there, if not copy over)
* from .../dos/c$ launch BOSBox "dosbox &" (not with the DOSBox icon)
   .../dos/c$dosbox & 
* in DOSBox enter "mount c /home/wikiuser/dos/c"
  Z:\>mount c /home/user/dos/c
*then enter c:
  C:\>
  C:\>dir (to check files in the directory) 
  (ddz11dos.exe, dos4gw.exe, seriff.fon, smallf.fon shouls be there)
* to run DDLab enter "\ddz11dos"
C:ddz11dos

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Compiling DDLab for DOS
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Compile DDLab for DOS with Open Watcom C/C++ installed (version 1.9 used here)
Check that the DDLab subdirectory of the watcom directory 
has files *.c *.h, dos4gw.exe, seriff.fon, small.fon)

from the command line in a DOS or terminal window in C:\watcom ...
first run the following command 
C:\watcom> runfirstBAT  (alternatively amend paths etc)
reply will be ...
Win32 BAT file set
then
cd ddlabz11 (the DDLab subdirectory) 
then (recommended)...
Compile and link all .c filed in the directory to make ddz11dos.exe:
C:\watcom\ddlabz10>wcl386 /l=dos4g *.c /fe=ddz11dos /j/zq/oneatx/zp4/5r
this creates .obj files and links them to make ddz11dos.exe
(the filename "ddz11dos.exe" must be max 8 chrs or less before .exe,
the DOS convention)

(to compile just one file, or just link .obj files, or create swapspace, see below)
the parameters  /j/zq/oneatx/zp4/5r have been used, meaning below ...

meaning of parameters
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/j - change char default from unsigned to signed
/zq - operate quietly
/o? followed by ....
n - replace floating-point divisions with multiplications - faster code
a - global variables not indirectly referenced through pointers, smaller code
e - expand small function inline
t - time favored over space - faster code but possibly larger
x - fastest exec code possible irrespective of architecture
r - essential for fast code for pentium

/zp4 - alignmet of structure members ??

/5r - generate 386 instructions base on Intel Pentium instruction timings ...
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to Compile and link all .c filed in the directory to make ddz11dos.exe see above:
to compile just one file, or just link .obj files, or create swapspace:

Compile one .c file:
C:\watcom\ddlabz10>wcc386 l_save09 /j/zq/oneatx/zp4/5r
Link all .obj filed in directory to make ddz11dos.exe
C:\watcom\ddlabz11>wcl386 /l=dos4g *.obj /fe=ddz11dos /j/zq/oneatx/zp4/5r
Create swapspace:
C:\watcom\ddlabz10>set dos4gvm=maxmem#8192 virtualsize#32768 swapname#ddz11dos.swp
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