diff --git a/src/option.c b/src/option.c
index 0c38de6..dae2054 100644
--- a/src/option.c
+++ b/src/option.c
@@ -464,7 +464,7 @@
 
 /* 'isprint' for latin1 is also used for MS-Windows cp1252, where 0x80 is used
  * for the currency sign. */
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+#if defined(MSDOS) || defined(MSWIN)
 # define ISP_LATIN1 (char_u *)"@,~-255"
 #else
 # define ISP_LATIN1 (char_u *)"@,161-255"
@@ -501,7 +501,7 @@
 			    (char_u *)NULL, PV_NONE,
 #endif
 			    {
-#if (defined(MSDOS) || defined(WIN3264) || defined(OS2)) && !defined(FEAT_GUI_W32)
+#if (defined(MSDOS) || defined(WIN3264)) && !defined(FEAT_GUI_W32)
 			    (char_u *)128L,
 #else
 			    (char_u *)224L,
@@ -576,7 +576,7 @@
     {"background",  "bg",   P_STRING|P_VI_DEF|P_RCLR,
 			    (char_u *)&p_bg, PV_NONE,
 			    {
-#if (defined(MSDOS) || defined(OS2) || defined(WIN3264)) && !defined(FEAT_GUI)
+#if (defined(MSDOS) || defined(WIN3264)) && !defined(FEAT_GUI)
 			    (char_u *)"dark",
 #else
 			    (char_u *)"light",
@@ -1600,7 +1600,7 @@
     {"isident",	    "isi",  P_STRING|P_VI_DEF|P_COMMA|P_NODUP,
 			    (char_u *)&p_isi, PV_NONE,
 			    {
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+#if defined(MSDOS) || defined(MSWIN)
 			    (char_u *)"@,48-57,_,128-167,224-235",
 #else
 # ifdef EBCDIC
@@ -1626,7 +1626,7 @@
 				    "251-254",
 #else
 				(char_u *)"@,48-57,_",
-# if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+# if defined(MSDOS) || defined(MSWIN)
 				(char_u *)"@,48-57,_,128-167,224-235"
 # else
 				ISK_LATIN1
@@ -1636,7 +1636,7 @@
     {"isprint",	    "isp",  P_STRING|P_VI_DEF|P_RALL|P_COMMA|P_NODUP,
 			    (char_u *)&p_isp, PV_NONE,
 			    {
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2) \
+#if defined(MSDOS) || defined(MSWIN) \
 		|| (defined(MACOS) && !defined(MACOS_X)) \
 		|| defined(VMS)
 			    (char_u *)"@,~-255",
@@ -1682,14 +1682,10 @@
 #ifdef VMS
 			    (char_u *)"help",
 #else
-# if defined(OS2)
-			    (char_u *)"view /",
-# else
-#  ifdef USEMAN_S
+# ifdef USEMAN_S
 			    (char_u *)"man -s",
-#  else
+# else
 			    (char_u *)"man",
-#  endif
 # endif
 #endif
 #endif
@@ -1737,7 +1733,7 @@
     {"lines",	    NULL,   P_NUM|P_NODEFAULT|P_NO_MKRC|P_VI_DEF|P_RCLR,
 			    (char_u *)&Rows, PV_NONE,
 			    {
-#if defined(MSDOS) || defined(WIN3264) || defined(OS2)
+#if defined(MSDOS) || defined(WIN3264)
 			    (char_u *)25L,
 #else
 			    (char_u *)24L,
@@ -1969,7 +1965,7 @@
 			    (char_u *)NULL, PV_NONE,
 			    {(char_u *)FALSE, (char_u *)0L} SCRIPTID_INIT},
     {"opendevice",  "odev", P_BOOL|P_VI_DEF,
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+#if defined(MSDOS) || defined(MSWIN)
 			    (char_u *)&p_odev, PV_NONE,
 #else
 			    (char_u *)NULL, PV_NONE,
@@ -2301,14 +2297,10 @@
 #   if defined(WIN3264)
 			    (char_u *)"",	/* set in set_init_1() */
 #   else
-#    if defined(OS2)
-			    (char_u *)"cmd.exe",
-#    else
-#     if defined(ARCHIE)
+#    if defined(ARCHIE)
 			    (char_u *)"gos",
-#     else
+#    else
 			    (char_u *)"sh",
-#     endif
 #    endif
 #   endif
 #  endif
@@ -2321,18 +2313,14 @@
 #if defined(MSDOS) || defined(MSWIN)
 			    (char_u *)"/c",
 #else
-# if defined(OS2)
-			    (char_u *)"/c",
-# else
 			    (char_u *)"-c",
-# endif
 #endif
 				(char_u *)0L} SCRIPTID_INIT},
     {"shellpipe",   "sp",   P_STRING|P_VI_DEF|P_SECURE,
 #ifdef FEAT_QUICKFIX
 			    (char_u *)&p_sp, PV_NONE,
 			    {
-#if defined(UNIX) || defined(OS2)
+#if defined(UNIX)
 # ifdef ARCHIE
 			    (char_u *)"2>",
 # else
@@ -2765,7 +2753,7 @@
     {"undolevels",  "ul",   P_NUM|P_VI_DEF,
 			    (char_u *)&p_ul, PV_UL,
 			    {
-#if defined(UNIX) || defined(WIN3264) || defined(OS2) || defined(VMS)
+#if defined(UNIX) || defined(WIN3264) || defined(VMS)
 			    (char_u *)1000L,
 #else
 			    (char_u *)100L,
@@ -2807,7 +2795,7 @@
     {"viminfo",	    "vi",   P_STRING|P_ONECOMMA|P_NODUP|P_SECURE,
 #ifdef FEAT_VIMINFO
 			    (char_u *)&p_viminfo, PV_NONE,
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+#if defined(MSDOS) || defined(MSWIN)
 			    {(char_u *)"", (char_u *)"'100,<50,s10,h,rA:,rB:"}
 #else
 # ifdef AMIGA
@@ -3199,7 +3187,7 @@
      * Don't use it if it is empty.
      */
     if (((p = mch_getenv((char_u *)"SHELL")) != NULL && *p != NUL)
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+#if defined(MSDOS) || defined(MSWIN)
 # ifdef __EMX__
 	    || ((p = mch_getenv((char_u *)"EMXSHELL")) != NULL && *p != NUL)
 # endif
@@ -3349,10 +3337,10 @@
     }
 #endif
 
-#if defined(FEAT_POSTSCRIPT) && (defined(MSWIN) || defined(OS2) || defined(VMS) || defined(EBCDIC) || defined(MAC) || defined(hpux))
+#if defined(FEAT_POSTSCRIPT) && (defined(MSWIN) || defined(VMS) || defined(EBCDIC) || defined(MAC) || defined(hpux))
     /* Set print encoding on platforms that don't default to latin1 */
     set_string_default("penc",
-# if defined(MSWIN) || defined(OS2)
+# if defined(MSWIN)
 		       (char_u *)"cp1252"
 # else
 #  ifdef VMS
@@ -3375,7 +3363,7 @@
 #ifdef FEAT_POSTSCRIPT
     /* 'printexpr' must be allocated to be able to evaluate it. */
     set_string_default("pexpr",
-# if defined(MSWIN) || defined(MSDOS) || defined(OS2)
+# if defined(MSWIN) || defined(MSDOS)
 	    (char_u *)"system('copy' . ' ' . v:fname_in . (&printdevice == '' ? ' LPT1:' : (' \"' . &printdevice . '\"'))) . delete(v:fname_in)"
 # else
 #  ifdef VMS
@@ -3525,7 +3513,7 @@
 		options[opt_idx].flags |= P_DEF_ALLOCED;
 	    }
 
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2) || defined(MACOS) \
+#if defined(MSDOS) || defined(MSWIN) || defined(MACOS) \
 		|| defined(VMS)
 	    if (STRCMP(p_enc, "latin1") == 0
 # ifdef FEAT_MBYTE
@@ -3809,7 +3797,7 @@
     set_number_default("window", Rows - 1);
 
     /* For DOS console the default is always black. */
-#if !((defined(MSDOS) || defined(OS2) || defined(WIN3264)) && !defined(FEAT_GUI))
+#if !((defined(MSDOS) || defined(WIN3264)) && !defined(FEAT_GUI))
     /*
      * If 'background' wasn't set by the user, try guessing the value,
      * depending on the terminal name.  Only need to check for terminals
@@ -3852,7 +3840,7 @@
     static char_u *
 term_bg_default()
 {
-#if defined(MSDOS) || defined(OS2) || defined(WIN3264)
+#if defined(MSDOS) || defined(WIN3264)
     /* DOS console nearly always black */
     return (char_u *)"dark";
 #else
@@ -3877,7 +3865,7 @@
     void
 set_init_3()
 {
-#if defined(UNIX) || defined(OS2) || defined(WIN3264)
+#if defined(UNIX) || defined(WIN3264)
 /*
  * Set 'shellpipe' and 'shellredir', depending on the 'shell' option.
  * This is done after other initializations, where 'shell' might have been
@@ -3886,23 +3874,23 @@
     char_u  *p;
     int	    idx_srr;
     int	    do_srr;
-#ifdef FEAT_QUICKFIX
+# ifdef FEAT_QUICKFIX
     int	    idx_sp;
     int	    do_sp;
-#endif
+# endif
 
     idx_srr = findoption((char_u *)"srr");
     if (idx_srr < 0)
 	do_srr = FALSE;
     else
 	do_srr = !(options[idx_srr].flags & P_WAS_SET);
-#ifdef FEAT_QUICKFIX
+# ifdef FEAT_QUICKFIX
     idx_sp = findoption((char_u *)"sp");
     if (idx_sp < 0)
 	do_sp = FALSE;
     else
 	do_sp = !(options[idx_sp].flags & P_WAS_SET);
-#endif
+# endif
     p = get_isolated_shell_name();
     if (p != NULL)
     {
@@ -3912,23 +3900,23 @@
 	 */
 	if (	   fnamecmp(p, "csh") == 0
 		|| fnamecmp(p, "tcsh") == 0
-# if defined(OS2) || defined(WIN3264)	/* also check with .exe extension */
+# if defined(WIN3264)	/* also check with .exe extension */
 		|| fnamecmp(p, "csh.exe") == 0
 		|| fnamecmp(p, "tcsh.exe") == 0
 # endif
 	   )
 	{
-#if defined(FEAT_QUICKFIX)
+# if defined(FEAT_QUICKFIX)
 	    if (do_sp)
 	    {
-# ifdef WIN3264
+#  ifdef WIN3264
 		p_sp = (char_u *)">&";
-# else
+#  else
 		p_sp = (char_u *)"|& tee";
-# endif
+#  endif
 		options[idx_sp].def_val[VI_DEFAULT] = p_sp;
 	    }
-#endif
+# endif
 	    if (do_srr)
 	    {
 		p_srr = (char_u *)">&";
@@ -3936,7 +3924,7 @@
 	    }
 	}
 	else
-# ifndef OS2	/* Always use bourne shell style redirection if we reach this */
+	    /* Always use bourne shell style redirection if we reach this */
 	    if (       fnamecmp(p, "sh") == 0
 		    || fnamecmp(p, "ksh") == 0
 		    || fnamecmp(p, "mksh") == 0
@@ -3945,7 +3933,7 @@
 		    || fnamecmp(p, "zsh-beta") == 0
 		    || fnamecmp(p, "bash") == 0
 		    || fnamecmp(p, "fish") == 0
-#  ifdef WIN3264
+# ifdef WIN3264
 		    || fnamecmp(p, "cmd") == 0
 		    || fnamecmp(p, "sh.exe") == 0
 		    || fnamecmp(p, "ksh.exe") == 0
@@ -3955,21 +3943,20 @@
 		    || fnamecmp(p, "zsh-beta.exe") == 0
 		    || fnamecmp(p, "bash.exe") == 0
 		    || fnamecmp(p, "cmd.exe") == 0
-#  endif
-		    )
 # endif
+		    )
 	    {
-#if defined(FEAT_QUICKFIX)
+# if defined(FEAT_QUICKFIX)
 		if (do_sp)
 		{
-# ifdef WIN3264
+#  ifdef WIN3264
 		    p_sp = (char_u *)">%s 2>&1";
-# else
+#  else
 		    p_sp = (char_u *)"2>&1| tee";
-# endif
+#  endif
 		    options[idx_sp].def_val[VI_DEFAULT] = p_sp;
 		}
-#endif
+# endif
 		if (do_srr)
 		{
 		    p_srr = (char_u *)">%s 2>&1";
@@ -3980,7 +3967,7 @@
     }
 #endif
 
-#if defined(MSDOS) || defined(WIN3264) || defined(OS2)
+#if defined(MSDOS) || defined(WIN3264)
     /*
      * Set 'shellcmdflag', 'shellxquote', and 'shellquote' depending on the
      * 'shell' option.
@@ -7043,7 +7030,7 @@
     {
 	if (VIM_ISDIGIT(*p_bs))
 	{
-	    if (*p_bs >'2' || p_bs[1] != NUL)
+	    if (*p_bs > '2' || p_bs[1] != NUL)
 		errmsg = e_invarg;
 	}
 	else if (check_opt_strings(p_bs, p_bs_values, TRUE) != OK)