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Samuel Gomes edited this page Nov 8, 2022 · 1 revision

ASCII and Extended Codes

MS-DOS code page 437

ASCII Control 0 to 31 | ASCII Keyboard Character Codes 32 to 127

Code Character [key] Code Character Code Character Code Character
0 (NUL) 32 [SPACE$] 64 @ 96 `
1 ☺ (SOH) 33 ! 65 A 97 a
2 ☻ (STX) 34 " 66 B 98 b
3 ♥ (ETX) 35 # 67 C 99 c
4 ♦ (EOT) 36 $ 68 D 100 d
5 ♣ (ENQ) 37 % 69 E 101 e
6 ♠ (ACK) 38 & 70 F 102 f
7 • (BEL) [BEEP](BEEP) 39 ' 71 G 103 g
8 ◘ [BackSpace] ** 40 ( 72 H 104 h
9 ○ (HT) [TAB] ** 41 ) 73 I 105 i
10 ◙ (LineFeed) ** 42 * 74 J 106 j
11 ♂ (VT) ** 43 + 75 K 107 k
12 ♀ (FormFeed) ** 44 , 76 L 108 l
13 ♪ (CR) [Enter] ** 45 - 77 M 109 m
14 ♫ (SO) 46 . 78 N 110 n
15 ¤ (SI) 47 / 79 O 111 o
16 ► (DLE) 48 0 80 P 112 p
17 ◄ (DC1) 49 1 81 Q 113 q
18 ↕ (DC2) 50 2 82 R 114 r
19 ‼ (DC3) 51 3 83 S 115 s
20 ¶ (DC4) 52 4 84 T 116 t
21 § (NAK) 53 5 85 U 117 u
22 ▬ (SYN) 54 6 86 V 118 v
23 ↨ (ETB) 55 7 87 W 119 w
24 ↑ (CAN) 56 8 88 X 120 x
25 ↓ (EM) 57 9 89 Y 121 y
26 → (SUB) EOF 58 : 90 Z 122 z
27 ← (ESC) [Esc] 59 ; 91 [ 123 {
28 ∟ (FS) ** 60 < 92 \ 124 |
29 ↔ (GS) ** 61 = 93 ] 125 }
30 ▲ (RS) ** 62 > 94 ^ 126 ~
31 ▼ (US) ** 63 ? 95 _ 127 ¦ (DEL) *

IBM, International, graphical, mathematical and other characters

Code Character Code Character Code Character Code Character
128 Ç 160 á 192 + 224 a
129 ü 161 í 193 - 225 ß
130 é 162 ó 194 - 226 G
131 â 163 ú 195 + 227 p
132 ä 164 ñ 196 - 228 S
133 à 165 Ñ 197 + 229 s
134 å 166 ª 198 ¦ 230 µ
135 ç 167 º 199 ¦ 231 t
136 ê 168 ¿ 200 + 232 F
137 ë 169 ¬ 201 + 233 T
138 è 170 ¬ 202 - 234 O
139 ï 171 ½ 203 - 235 d
140 î 172 ¼ 204 ¦ 236 8
141 ì 173 ¡ 205 - 237 f
142 Ä 174 « 206 + 238 e
143 Å 175 » 207 - 239 n
144 É 176 ¦ 208 - 240 =
145 æ 177 ¦ 209 - 241 ±
146 Æ 178 ¦ 210 - 242 =
147 ô 179 ¦ 211 + 243 =
148 ö 180 ¦ 212 + 244 (
149 ò 181 ¦ 213 + 245 )
150 û 182 ¦ 214 + 246 ÷
151 ù 183 + 215 + 247 ˜
152 ÿ 184 + 216 + 248 °
153 Ö 185 ¦ 217 + 249 ·
154 Ü 186 ¦ 218 + 250 ·
155 ¢ 187 + 219 ¦ 251 v
156 £ 188 + 220 _ 252 n
157 ¥ 189 + 221 ¦ 253 ²
158 P 190 + 222 ¦ 254 ¦
159 ƒ 191 + 223 ¯ 255 NBSP ***
  • * DEL was used to erase paper tape data by punching out all of the 7 holes.**
  • ** Control characters 8 to 13 and 28 to 31 can move text formatting when PRINT and do not display
  • *** NBSP is a Non-breaking Space used to indent text. Some browsers may handle this character differently**

More information about ASCII Control Characters

Unicode

Control Characters

  • INKEY$ will return Control + letter key press combinations as the equivalent control characters or bold function keys listed below:
Code C Description Code C Description
CTRL + A = CHR$(1) StartHeader (SOH) CTRL + B = CHR$(2) StartText (STX)
CTRL + C = CHR$(3) EndText (ETX) CTRL + D = CHR$(4) EndOfTransmit (EOT)
CTRL + E = CHR$(5) Enquiry (ENQ) CTRL + F = CHR$(6) Acknowledge (ACK)
CTRL + G = CHR$(7) Bell (BEL) CTRL + H = CHR$(8) [Backspace] (BSP)
CTRL + I = CHR$(9) Horiz.Tab [Tab] CTRL + J = CHR$(10) LineFeed(printer) (LF)
CTRL + K = CHR$(11) Vert. Tab (VT) CTRL + L = CHR$(12) FormFeed(printer) (FF)
CTRL + M = CHR$(13) [Enter] (CR) CTRL + N = CHR$(14) ShiftOut (SO)
CTRL + O = CHR$(15) ShiftIn (SI) CTRL + P = CHR$(16) DataLinkEscape (DLE)
CTRL + Q = CHR$(17) DevControl1 (DC1) CTRL + R = CHR$(18) DeviceControl2 (DC2)
CTRL + S = CHR$(19) DevControl3 (DC3) CTRL + T = CHR$(20) DeviceControl4 (DC4)
CTRL + U = CHR$(21) § NegativeACK (NAK) CTRL + V = CHR$(22) Synchronous Idle (SYN)
CTRL + W = CHR$(23) EndTXBlock (ETB) CTRL + X = CHR$(24) Cancel (CAN)
CTRL + Y = CHR$(25) EndMedium (EM) CTRL + Z = CHR$(26) End Of File(SUB) (EOF)

Highlighted items will format text and not PRINT the symbol. _PRINTSTRING can print in QB64

  • Control characters 1 to 26 can be used to simulate Ctrl + letter key shortcuts in Windows programs using _SCREENPRINT.
  • _CONTROLCHR OFF can also be used in QB64 to allow control characters to be printed without formatting the text.

ASCII in Text and Printing

  • Characters 0(NULL) and 255(NBSP) can also be used to print spaces(32). Useful for making file names harder to delete too.
  • Character 7 will create a BEEP sound when printed in QB64 or an error sound in QBasic using a SCREEN 0 window.
  • Character 8 is returned when the Backspace key is pressed.
  • Characters 9 thru 13 and 28 thru 31 can affect screen or file text placements and do not display the character when PRINT:
    • Character 9 will Tab space the cursor 8 column spaces when printed.
    • Character 10 moves the cursor or "line feeds" the printer head down one row.
    • Character 11 vertical tabs the cursor back to top left position of page or screen. Acts like CLS.
    • Character 12 acts like CLS when printed. "Form feeds" the page out of printers.
    • Character 13 is the cursor or typing "carriage return" to the start of the line on left side. Returned when Enter key pressed.
    • Character 28 designates a File Separator. Moves the print cursor one space right. Combination Ctrl + \
    • Character 29 designates a Group Separator. Moves the print cursor one space left. Combination Ctrl + ]
    • Character 30 designates a Record Separator. Moves the print cursor one row up. Combination Ctrl + ^
    • Character 31 designates a Unit Separator. Moves the print cursor one row down. Combination Ctrl + _
  • QB64 can display all of the control characters without formatting the text using _PRINTSTRING.
  • Characters 13 and 10 can be combined to create the CrLf carriage return used in files or printing. crlf$ = CHR$(13) + CHR$(10).
  • Character 16, the data link escape(DLE) character, can designate that a control character is being sent from a OPEN COM. Example(s) (DLE) <XON> <DATA PACKET> (DLE) <XOFF> or (DLE) <STX> <DATA PACKET> (DLE) <ETX>
  • Character 17, Device Control 1, is used with OPEN COM to mark the start of a transmission as "XON". The character is read.
  • Character 19, Device Control 3, is used with OPEN COM to mark the end of a transmission as "XOFF". The character is NOT read.
  • Character 26 can be used to designate the end of a file. See EOF.
  • Character 27 ? is returned when the Escape key is pressed.

Control character PRINT actions can be controlled using _CONTROLCHR OFF or ON in QB64.

SCREEN 12
COLOR 14: PRINT "Press Control + letter key combinations."
DO
  K$ = INKEY$
  IF LEN(K$) THEN
    code = ASC(K$)
    IF code < 32 THEN _PRINTSTRING (220, 100), "Ctrl + " + CHR$(code + 64) + " = " + K$ + " "
  END IF
LOOP UNTIL K$ = CHR$(27)

END 

ASCII Character Usage

  • Characters are one byte and take up one space(byte) in a STRING value or variable.
  • Extended(non-keyboard) characters can be entered by holding down Alt key and entering the code number on the Number pad.
  • PRINTs text characters and symbols or formats the screen, printer or file.
  • BINARY files often store values below 256 in the one byte character. To read the value get the code with ASC.
  • Numerical values placed into a BINARY or RANDOM file using a GET or PUT variable, they will be stored in _MK$ format.
  • Characters 176 to 223 can be used to create screen borders or boundaries in an ASCII game. See: SCREEN (function)
  • Character 253(small 2) can be found as the first character byte of a BSAVEd image file opened in BINARY mode.
  • Character 255 can be used as the NBSP(non-breaking space) character on web pages to fill in extra spaces.
  • Can be used to crudely encrypt a file so others cannot read it by shifting the code values. See CHR$ example 2.

ASC Codes

ASC cannot read empty INKEY$ = "" loop reads! Check for them before reading ASC key press codes!


'                                **ASCII Keyboard Codes**
'
**' Esc  F1  F2  F3  F4  F5  F6  F7  F8  F9  F10  F11  F12  Sys ScL Pause**
'  27 +59 +60 +61 +62 +63 +64 +65 +66 +67 +68  +133 +134   -   -    -
**' `~  1!  2@  3#  4$  5%  6^  7&  8*  9(  0) -_ =+ BkSp   Ins Hme PUp   NumL  /   *    -**
' 126 33  64  35  36  37  94  38  42  40  41 95 43   8    +82 +71 +73    -    47  42   45
**  96 49  50  51  52  53  54  55  56  57  48 45 61*
**' Tab Q   W   E   R   T   Y   U   I   O   P  [{  ]}  \|   Del End PDn   7Hme 8/?  9PU  + **
'  9  81  87  69  82  84  89  85  73  79  80 123 125 124  +83 +79 +81   +71  +72  +73  43
**    113 119 101 114 116 121 117 105 111 112  91  93  92                 55   56   57 *
**' CapL  A   S   D   F   G   H   J   K   L   ;:  '" Enter                4/?-  5   6/-?
'   -   65  83  68  70  71  72  74  75  76  58  34  13                  +75  +76  +77  **E**
**       97 115 100 102 103 104 106 107 108  59  39                       52   53   54 * **n**
**' Shift  Z   X   C   V   B   N   M   ,<  .>  /?    Shift       ?        1End 2/?  3PD  t**
'   *    90  88  67  86  66  78  77  60  62  63      *        +72       +79  +80  +81  **e**
**       122 120  99 118  98 110 109  44  46  47                          49   50   51 * **r**
**' Ctrl Win Alt       Spacebar          Alt Win Menu Ctrl   ?-  ?   -?   0Ins     .Del **
'  *    -   *           32              *   -   -    *    +75 +80 +77   +82       +83  13
'                                                                   *     48        46*
'
' **    *Italics* = LCase/NumLock On  ____________  + = 2 Byte: CHR$(0) + CHR$(code)**
'<sub>NOTE: The above commented table can be copied and pasted directly into the QB64 IDE</sub>

Use ASC(RIGHT$(key$, 1)) or ASC(key$, 2) in QB64 to read a two byte code when ASC(key$) = 0

*** See the Two Byte Ctrl, Alt and Shift + Function key combinations below**

'             Demo displays all ASCII codes and 2 byte code combinations
DO: K$ = INKEY$
  IF K$ <> "" THEN      'ASC will return an error if an empty string is read!
    IF ASC(K$) > 0 THEN
      PRINT "CHR$(" + LTRIM$(STR$(ASC(K$))) + ")"  'display normal keypress codes
    ELSE PRINT "CHR$(0) + CHR$(" + LTRIM$(STR$(ASC(K$, 2))) + ")"  'display 2 byte codes
    END IF
  END IF
LOOP UNTIL K$ = CHR$(27) 'escape key press exits 

Note: In QB64 ASC(K$, 2) can read the second byte of the 2 byte code when ASC(K$) reads the first byte as 0.

Two Byte Codes

Two Byte ASCII Keyboard Return Values

  • INKEY$ returns both bytes when two byte keys or key combinations are pressed. The second byte = RIGHT$(keypress$, 1)
  • If the character returned is a two byte code, ASC will return 0. Warning: ASC cannot read empty INKEY$ string values!
  • In QB64 only, ASC(keypress$, 2) can return the second byte code. Don't read empty string values!
  • String values returned can be compared in an IF...THEN or SELECT CASE routine by using the actual string definitions such as:

IF INKEY$ = CHR$(0) + CHR$(80) THEN row = row + 1 or IF INKEY$ = CHR$(0) + "P" THEN row = row + 1


                 **Two Byte Character Codes       Key                 CHR$(0) + "?" **

                    CHR$(0) + CHR$(16-50)      [Alt] + letter
                    CHR$(0) + CHR$(59)         [F1]                 ";"
                    CHR$(0) + CHR$(60)         [F2]                 "<"
                    CHR$(0) + CHR$(61)         [F3]                 "="
                    CHR$(0) + CHR$(62)         [F4]                 ">"
                    CHR$(0) + CHR$(63)         [F5]                 "?"
                    CHR$(0) + CHR$(64)         [F6]                 "@"
                    CHR$(0) + CHR$(65)         [F7]                 "A"
                    CHR$(0) + CHR$(66)         [F8]                 "B"
                    CHR$(0) + CHR$(67)         [F9]                 "C"
                    CHR$(0) + CHR$(68)         [F10]                "D"
                    CHR$(0) + CHR$(71)         [Home]               "G"
                    CHR$(0) + CHR$(72)         [?] Up Arrow         "H"
                    CHR$(0) + CHR$(73)         [Page Up]            "I"
                    CHR$(0) + CHR$(75)         [?] Left Arrow       "K"
                    CHR$(0) + CHR$(76)         [5 NumberPad]        "L" (NumLock off in QB64)
                    CHR$(0) + CHR$(77)         [?] Right Arrow      "M"
                    CHR$(0) + CHR$(79)         [End]                "O"
                    CHR$(0) + CHR$(80)         [?] Down Arrow       "P"
                    CHR$(0) + CHR$(81)         [Page Down]          "Q"
                    CHR$(0) + CHR$(82)         [Insert]             "R"
                    CHR$(0) + CHR$(83)         [Delete]             "S"
                    CHR$(0) + CHR$(84-93)      [Shift] + F1-10
                    CHR$(0) + CHR$(94-103)     [Ctrl] + F1-10
                    CHR$(0) + CHR$(104-113)    [Alt] + F1-10
                    CHR$(0) + CHR$(114-119)    [Ctrl] + keypad
                    CHR$(0) + CHR$(120-129)    [Alt] + number
                    CHR$(0) + CHR$(130 or 131) [Alt] + _/- or +/=   "é" or "â"
                    CHR$(0) + CHR$(133)        [F11]                "à"
                    CHR$(0) + CHR$(134)        [F12]                "å"
                    CHR$(0) + CHR$(135)        [Shift] + [F11]      "ç"
                    CHR$(0) + CHR$(136)        [Shift] + [F12]      "ê"
                    CHR$(0) + CHR$(137)        [Ctrl] + [F11]       "ë"
                    CHR$(0) + CHR$(138)        [Ctrl] + [F12]       "è"
                    CHR$(0) + CHR$(139)        [Alt] + [F11]        "ï"
                    CHR$(0) + CHR$(140)        [Alt] + [F12]        "î"

In QB64, CVI can be used to get the _KEYDOWN 2-byte code value. Example: status = _KEYDOWN(CVI(CHR$(0) + "P"))

See Scancodes for other keyboard function keys.

Code Examples

Using arrow keys to move a text character. A change from a previous position tells program when to PRINT:

movey = 1: movex = 1 'text coordinates can never be 0
at$ = "@"  'text sprite could be almost any ASCII character
LOCATE movey, movex: PRINT at$;
DO
    px = movex: py = movey 'previous positions
    B$ = INKEY$
    IF B$ = CHR$(0) + CHR$(72) AND movey > 1 THEN movey = movey - 1 'rows 1 to 23 only
    IF B$ = CHR$(0) + CHR$(80) AND movey < 23 THEN movey = movey + 1
    IF B$ = CHR$(0) + CHR$(75) AND movex > 1 THEN movex = movex - 1 'columns 1 to 80 only
    IF B$ = CHR$(0) + CHR$(77) AND movex < 80 THEN movex = movex + 1

    IF px <> movex OR py <> movey THEN 'only changes when needed
        LOCATE py, px: PRINT SPACE$(1); 'erase old sprite
        LOCATE movey, movex: PRINT at$; 'show new position
    END IF
LOOP UNTIL B$ = CHR$(27) 'ESCape key exit
END

Routine displays all keypress codes including Ctrl, Alt and Shift combinations. Ctrl + letter = control codes 1 to 26.

 * *
 SCREEN 13
 tmp$ = "   CHR$(###),\\,\          \       "
 tmp2$ = "  CHR$(0) + CHR$(###) \           \"
 COLOR 14: LOCATE 3, 3: PRINT "The code can tell what key is pressed"
 COLOR 12: LOCATE 5, 14: PRINT CHR$(3); SPACE$(3);
 COLOR 13: PRINT CHR$(5); SPACE$(3);
 COLOR 12: PRINT CHR$(4); SPACE$(3);
 COLOR 13: PRINT CHR$(6)
 COLOR 10: LOCATE 7, 4: PRINT " Hit a key to find the ASCII Code"
 COLOR 5: LOCATE 13, 1: PRINT " Codes below 33 are called control keys"
 LOCATE 14, 1: PRINT " CHR$(0) + are 2 byte Extended key codes"
 COLOR 13: LOCATE 16, 1: PRINT " Extended: Press Alt + numberpad: Enter"
 LOCATE 18, 1: PRINT "  Try some Ctrl, Alt, or Shift Combo's"
 COLOR 5: LOCATE 20, 1: PRINT " INKEY$ is used to detect the key entry"
 COLOR 2: LOCATE 22, 15: PRINT CHR$(1); "       "; CHR$(2)
 COLOR 4: LOCATE 24, 10: PRINT "To Quit hit the TAB key";

 COLOR 9
 DO
     DO: SLEEP: A$ = INKEY$: LOOP UNTIL A$ <> ""  'legal ASC read keys
     IF ASC(A$) > 0 THEN  ' normal key codes
         code% = ASC(A$)
         SELECT CASE code%
           CASE 7: Key$ = "Beep"
           CASE 8: Key$ = "Backspace"
           CASE 9: Key$ = "Tab Key"
           CASE 10: Key$ = "Line Feed"
           CASE 12: Key$ = "Form Feed"
           CASE 13: Key$ = "Enter"
           CASE 27: Key$ = "Escape"
           CASE 32: Key$ = "Space Bar"
           CASE 48 TO 57: Key$ = "Number"
           CASE 65 TO 90: Key$ = "Uppercase"
           CASE 97 TO 122: Key$ = "Lowercase"
           CASE ELSE: Key$ = ""
         END SELECT
         SELECT CASE code%  'check for unprintable control combo characters
           CASE 10 TO 13: Kcode% = 32
           CASE ELSE: Kcode% = code%
         END SELECT
         COLOR 9: LOCATE 10, 5: PRINT USING tmp$; code%; CHR$(Kcode%); Key$;
     END IF
     IF ASC(A$) = 0 THEN  'two byte key codes
         code% = ASC(RIGHT$(A$, 1)) 'QBasic code
         'code% = ASC(A$, 2)        'QB64 code alternative
         SELECT CASE code%
            CASE 16 TO 50: Key$ = "Alt+ letter"
            CASE 72: Key$ = CHR$(24) + " Arrow"
            CASE 75: Key$ = CHR$(27) + " Arrow"
            CASE 77: Key$ = CHR$(26) + " Arrow"
            CASE 80: Key$ = CHR$(25) + " Arrow"
            CASE 83: Key$ = "Delete"
            CASE 59: Key$ = "F1"
            CASE 60: Key$ = "F2"
            CASE 61: Key$ = "F3"
            CASE 62: Key$ = "F4"
            CASE 63: Key$ = "F5"
            CASE 64: Key$ = "F6"
            CASE 65: Key$ = "F7"
            CASE 66: Key$ = "F8"
            CASE 67: Key$ = "F9"
            CASE 68: Key$ = "F10"
            CASE 71: Key$ = "Home"
            CASE 73: Key$ = "Page " + CHR$(24)
            CASE 79: Key$ = "End"
            CASE 81: Key$ = "Page " + CHR$(25)
            CASE 82: Key$ = "Insert"
            CASE 83: Key$ = "Delete"
            CASE 84 TO 93: Key$ = "Shift+ F"
            CASE 94 TO 103: Key$ = "Ctrl+ F"
            CASE 104 TO 113: Key$ = "Alt+ F"
            CASE 114 TO 119: Key$ = "Ctrl + pad"
            CASE 120 TO 129: Key$ = "Alt+ number"
            CASE 132: Key$ = "Ctrl + pad"
            CASE 133: Key$ = "F11"
            CASE 134: Key$ = "F12"
            CASE 135: Key$ = "Shift+ F11"
            CASE 136: Key$ = "Shift+ F12"
            CASE 137: Key$ = "Ctrl+ F11"
            CASE 138: Key$ = "Ctrl+ F12"
            CASE 139: Key$ = "Alt+ F11"
            CASE 140: Key$ = "Alt+ F12"
            CASE ELSE: Key$ = ""
         END SELECT
         LOCATE 10, 5: PRINT USING tmp2$; code%; Key$
     END IF
 LOOP UNTIL A$ = CHR$(9)
 SOUND 400, 4
 SLEEP 3
 SYSTEM 

Code by Ted Weissgerber

Explanation: The routine checks for a keypress and SLEEP guarantees that ASC will never read an empty string from INKEY$. When the keypress is determined to be two bytes (ASC(A$) = 0) the second SELECT CASE routine is used. You can even display non-keyboard extended characters. Just press Alt + numberpad code, release and press enter.

Note: Ctrl + letter keys will list the contol keys as normal codes. EX: Ctrl + G will BEEP (CHR$(7)).

References

Printable ASCII Table: _PRINTIMAGE (see Example 2 on page)

See Also

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