new file mode 100644
--- /dev/null
+++ b/src/ascii.h
@@ -0,0 +1,201 @@
+/* vi:set ts=8 sts=4 sw=4:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read copying and usage conditions.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ */
+
+/*
+ * Definitions of various common control characters.
+ * For EBCDIC we have to use different values.
+ */
+
+#ifndef EBCDIC
+
+/* IF_EB(ASCII_constant, EBCDIC_constant) */
+#define IF_EB(a, b)	a
+
+#define CharOrd(x)	((x) < 'a' ? (x) - 'A' : (x) - 'a')
+#define CharOrdLow(x)	((x) - 'a')
+#define CharOrdUp(x)	((x) - 'A')
+#define ROT13(c, a)	(((((c) - (a)) + 13) % 26) + (a))
+
+#define NUL		'\000'
+#define BELL		'\007'
+#define BS		'\010'
+#define TAB		'\011'
+#define NL		'\012'
+#define NL_STR		(char_u *)"\012"
+#define FF		'\014'
+#define CAR		'\015'	/* CR is used by Mac OS X */
+#define ESC		'\033'
+#define ESC_STR		(char_u *)"\033"
+#define ESC_STR_nc	"\033"
+#define DEL		0x7f
+#define DEL_STR		(char_u *)"\177"
+#define CSI		0x9b	/* Control Sequence Introducer */
+#define CSI_STR		"\233"
+#define DCS		0x90	/* Device Control String */
+#define STERM		0x9c	/* String Terminator */
+
+#define POUND		0xA3
+
+#define Ctrl_chr(x)	(TOUPPER_ASC(x) ^ 0x40) /* '?' -> DEL, '@' -> ^@, etc. */
+#define Meta(x)		((x) | 0x80)
+
+#define CTRL_F_STR	"\006"
+#define CTRL_H_STR	"\010"
+#define CTRL_V_STR	"\026"
+#define CTRL_W_STR	"\027"
+
+#define Ctrl_AT		0   /* @ */
+#define Ctrl_A		1
+#define Ctrl_B		2
+#define Ctrl_C		3
+#define Ctrl_D		4
+#define Ctrl_E		5
+#define Ctrl_F		6
+#define Ctrl_G		7
+#define Ctrl_H		8
+#define Ctrl_I		9
+#define Ctrl_J		10
+#define Ctrl_K		11
+#define Ctrl_L		12
+#define Ctrl_M		13
+#define Ctrl_N		14
+#define Ctrl_O		15
+#define Ctrl_P		16
+#define Ctrl_Q		17
+#define Ctrl_R		18
+#define Ctrl_S		19
+#define Ctrl_T		20
+#define Ctrl_U		21
+#define Ctrl_V		22
+#define Ctrl_W		23
+#define Ctrl_X		24
+#define Ctrl_Y		25
+#define Ctrl_Z		26
+#define Ctrl_LSB	27  /* [ Left Square Bracket */
+#define Ctrl_BSL	28  /* \ BackSLash */
+#define Ctrl_RSB	29  /* ] Right Square Bracket */
+#define Ctrl_HAT	30  /* ^ */
+#define Ctrl__		31
+
+#else
+
+/* EBCDIC */
+
+/* IF_EB(ASCII_constant, EBCDIC_constant) */
+#define IF_EB(a, b)	b
+
+/*
+ * Finding the position in the alphabet is not straightforward in EBCDIC.
+ * There are gaps in the code table.
+ * 'a' + 1 == 'b', but: 'i' + 7 == 'j' and 'r' + 8 == 's'
+ */
+#define CharOrd__(c) ((c) < ('j' - 'a') ? (c) : ((c) < ('s' - 'a') ? (c) - 7 : (c) - 7 - 8))
+#define CharOrdLow(x) (CharOrd__((x) - 'a'))
+#define CharOrdUp(x) (CharOrd__((x) - 'A'))
+#define CharOrd(x) (isupper(x) ? CharOrdUp(x) : CharOrdLow(x))
+
+#define EBCDIC_CHAR_ADD_(x) ((x) < 0?'a':(x)>25?'z':"abcdefghijklmnopqrstuvwxyz"[x])
+#define EBCDIC_CHAR_ADD(c,s) (isupper(c) ? toupper(EBCDIC_CHAR_ADD_(CharOrdUp(c)+(s))) : EBCDIC_CHAR_ADD_(CharOrdLow(c)+(s)))
+
+#define R13_(c) ("abcdefghijklmnopqrstuvwxyz"[((c) + 13) % 26])
+#define ROT13(c, a)  (isupper(c) ? toupper(R13_(CharOrdUp(c))) : R13_(CharOrdLow(c)))
+
+#define NUL		'\000'
+#define BELL		'\x2f'
+#define BS		'\x16'
+#define TAB		'\x05'
+#define NL		'\x15'
+#define NL_STR		(char_u *)"\x15"
+#define FF		'\x0C'
+#define CAR		'\x0D'
+#define ESC		'\x27'
+#define ESC_STR		(char_u *)"\x27"
+#define ESC_STR_nc	"\x27"
+#define DEL		0x07
+#define DEL_STR		(char_u *)"\007"
+/* TODO: EBCDIC Code page dependent (here 1047) */
+#define CSI		0x9b	/* Control Sequence Introducer */
+#define CSI_STR		"\233"
+#define DCS		0x90	/* Device Control String */
+#define STERM		0x9c	/* String Terminator */
+
+#define POUND		'£'
+
+#define CTRL_F_STR	"\056"
+#define CTRL_H_STR	"\026"
+#define CTRL_V_STR	"\062"
+#define CTRL_W_STR	"\046"
+
+#define Ctrl_AT		0x00   /* @ */
+#define Ctrl_A		0x01
+#define Ctrl_B		0x02
+#define Ctrl_C		0x03
+#define Ctrl_D		0x37
+#define Ctrl_E		0x2D
+#define Ctrl_F		0x2E
+#define Ctrl_G		0x2F
+#define Ctrl_H		0x16
+#define Ctrl_I		0x05
+#define Ctrl_J		0x15
+#define Ctrl_K		0x0B
+#define Ctrl_L		0x0C
+#define Ctrl_M		0x0D
+#define Ctrl_N		0x0E
+#define Ctrl_O		0x0F
+#define Ctrl_P		0x10
+#define Ctrl_Q		0x11
+#define Ctrl_R		0x12
+#define Ctrl_S		0x13
+#define Ctrl_T		0x3C
+#define Ctrl_U		0x3D
+#define Ctrl_V		0x32
+#define Ctrl_W		0x26
+#define Ctrl_X		0x18
+#define Ctrl_Y		0x19
+#define Ctrl_Z		0x3F
+#define Ctrl_LSB	0x27  /* [ Left Square Bracket */
+#define Ctrl_RSB	0x1D  /* ] Right Square Bracket */
+#define Ctrl_BSL	0x1C  /* \ BackSLash */
+#define Ctrl_HAT	0x1E  /* ^ */
+#define Ctrl__		0x1F
+
+#define Ctrl_chr(x)	(CtrlTable[(x)])
+extern char CtrlTable[];
+
+#define CtrlChar(x)	((x < ' ') ? CtrlCharTable[(x)] : 0)
+extern char CtrlCharTable[];
+
+#define MetaChar(x)	((x < ' ') ? MetaCharTable[(x)] : 0)
+extern char MetaCharTable[];
+
+#endif /* defined EBCDIC */
+
+/*
+ * Character that separates dir names in a path.
+ * For MS-DOS, WIN32 and OS/2 we use a backslash.  A slash mostly works
+ * fine, but there are places where it doesn't (e.g. in a command name).
+ * For Macintosh we use a colon.
+ * For Acorn we use a dot.
+ */
+#ifdef BACKSLASH_IN_FILENAME
+# define PATHSEP	psepc
+# define PATHSEPSTR	pseps
+#else
+# ifdef COLON_AS_PATHSEP
+#  define PATHSEP	':'
+#  define PATHSEPSTR	":"
+# else
+#  ifdef RISCOS
+#   define PATHSEP	'.'
+#   define PATHSEPSTR	"."
+#  else
+#   define PATHSEP	'/'
+#   define PATHSEPSTR	"/"
+#  endif
+# endif
+#endif