1. in file:
        src/rules/mklcclib.bat

   "deltree /y" should be replaced by "rmdir /Q /S". - 2 occurences

2. in file src/rules/lccwin32.mak there are 8 spaces instead of one TAB at lines:
        77, 84, 87, 88

   a) also, the line 
RM = deltree /y
   should be changed to:
RM = del /Q /S

   b) to be able to link the graphapp.lib to a .dll, this line also has to be changed:

CFLAGS = -O -Zp4 -e5 -Dmain=app_main -I. -Iwin32 -Igui -Iimgfmt -Ilibgif -Ilibjpeg -Ilibpng -Ilibz

to

CFLAGS = -O -Zp4 -e5 -DCOMPILE_AS_A_DLL -Dmain=app_main -I. -Iwin32 -Igui -Iimgfmt -Ilibgif -Ilibjpeg -Ilibpng -Ilibz

3. If compiling after those changes, an error at file textundo.c will be generated:

lcc -O -Zp4 -e5 -Dmain=app_main -I. -Iwin32 -Igui -Iimgfmt -Ilibgif -Ilibjpe
g -Ilibpng -Ilibz -errout=gui/textundo.err -Fogui/textundo.obj gui/textundo.c
Error gui/textundo.c: 20 unknown enumeration 'TextCommand'

Fix is to changes these lines below (in src/gui/textundo.c)

typedef enum TextCommand TextCommand;
..
enum TextCommand {
        TC_UNDEFINED,
        TC_TYPING,
        TC_BKSP,
        TC_DEL,
        TC_PASTE,
        TC_CUT,
        TC_SELECT
};

to this:

typedef enum TextCommand {
        TC_UNDEFINED,
        TC_TYPING,
        TC_BKSP,
        TC_DEL,
        TC_PASTE,
        TC_CUT,
        TC_SELECT
} TextCommand;