diff --git a/src/xxd/xxd.c b/src/xxd/xxd.c
index 8cd760b..f76adaa 100644
--- a/src/xxd/xxd.c
+++ b/src/xxd/xxd.c
@@ -80,14 +80,7 @@
 #else
 # include <fcntl.h>
 #endif
-#ifdef __TSC__
-# define MSDOS
-#endif
-#if !defined(OS2) && defined(__EMX__)
-# define OS2
-#endif
-#if defined(MSDOS) || defined(WIN32) || defined(OS2) || defined(__BORLANDC__) \
-  || defined(CYGWIN)
+#if defined(WIN32) || defined(__BORLANDC__) || defined(CYGWIN)
 # include <io.h>	/* for setmode() */
 #else
 # ifdef UNIX
@@ -149,18 +142,10 @@
 #ifdef WIN32
 char osver[] = " (Win32)";
 #else
-# ifdef DJGPP
-char osver[] = " (dos 32 bit)";
-# else
-#  ifdef MSDOS
-char osver[] = " (dos 16 bit)";
-#  else
 char osver[] = "";
-#  endif
-# endif
 #endif
 
-#if defined(MSDOS) || defined(WIN32) || defined(OS2)
+#if defined(WIN32)
 # define BIN_READ(yes)  ((yes) ? "rb" : "rt")
 # define BIN_WRITE(yes) ((yes) ? "wb" : "wt")
 # define BIN_CREAT(yes) ((yes) ? (O_CREAT|O_BINARY) : O_CREAT)
@@ -203,8 +188,7 @@
 #endif
 
 #ifndef __P
-# if defined(__STDC__) || defined(MSDOS) || defined(WIN32) || defined(OS2) \
-		|| defined(__BORLANDC__)
+# if defined(__STDC__) || defined(WIN32) || defined(__BORLANDC__)
 #  define __P(a) a
 # else
 #  define __P(a) ()