diff --git a/main.c b/main.c
index 92e451f..4b3e788 100644
--- a/main.c
+++ b/main.c
@@ -110,6 +110,107 @@ static void vfd_transmit(void)
 }
 */
 
+/* ASCII characters encoded for 7 segments display
+ * starts with space, ends with tilde
+ */
+static const uint8_t ascii_7segments[] = {
+	0b00000000, // space
+	0b00110000, // ! (I)
+	0b00100010, // "
+	0b01011100, // # (o)
+	0b01101101, // $ (s)
+	0b01010010, // % (/)
+	0b01111101, // & (6)
+	0b00100000, // '
+	0b00111001, // ( ([)
+	0b00001111, // )
+	0b01110000, // *
+	0b01000110, // +
+	0b00010000, // ,
+	0b01000000, // -
+	0b00010000, // . (,)
+	0b01010010, // /
+	0b00111111, // 0
+	0b00000110, // 1
+	0b01011011, // 2
+	0b01001111, // 3
+	0b01100110, // 4
+	0b01101101, // 5
+	0b01111101, // 6
+	0b00000111, // 7
+	0b01111111, // 8
+	0b01101111, // 9
+	0b01001000, // : (=)
+	0b01001000, // ; (=)
+	0b01011000, // <
+	0b01001000, // =
+	0b01001100, // >
+	0b01010011, // ?
+	0b01111011, // @
+	0b01110111, // A
+	0b01111111, // B
+	0b00111001, // C
+	0b01011110, // D
+	0b01111001, // E
+	0b01110001, // F
+	0b00111101, // G
+	0b01110110, // H
+	0b00110000, // I
+	0b00011110, // J
+	0b01110110, // K
+	0b00111000, // L
+	0b00110111, // M
+	0b00110111, // N
+	0b00111111, // O
+	0b01110011, // P
+	0b01101011, // Q
+	0b00110011, // R
+	0b01101101, // S
+	0b01111000, // T
+	0b00111110, // U
+	0b00111110, // V (U)
+	0b00111110, // W (U)
+	0b01110110, // X (H)
+	0b01101110, // Y
+	0b01011011, // Z
+	0b00111001, // [
+	0b01100100, // '\'
+	0b00001111, // /
+	0b00100011, // ^
+	0b00001000, // _
+	0b00000010, // `
+	0b01011111, // a
+	0b01111100, // b
+	0b01011000, // c
+	0b01011110, // d
+	0b01111011, // e
+	0b01110001, // f
+	0b01101111, // g
+	0b01110100, // h
+	0b00010000, // i
+	0b00001100, // j
+	0b01110110, // k
+	0b00110000, // l
+	0b01010100, // m
+	0b01010100, // n
+	0b01011100, // o
+	0b01110011, // p
+	0b01100111, // q
+	0b01010000, // r
+	0b01101101, // s
+	0b01111000, // t
+	0b00011100, // u
+	0b00011100, // v (u)
+	0b00011100, // w (u)
+	0b01110110, // x
+	0b01101110, // y
+	0b01011011, // z
+	0b00111001, // { ([)
+	0b00110000, // |
+	0b00001111, // } ([)
+	0b01000000, // ~
+};
+
 /* put digit into memory */
 static void vfd_digit(uint8_t nb, char c)
 {
@@ -135,257 +236,12 @@ static void vfd_digit(uint8_t nb, char c)
 	}
 	if (false) { // add the comma (not encoded)
 		vfd_data[1] |= (1<<(16));
-	}
-	uint8_t segment = 0;
-	switch (c&0x7f) {
-		case '0':
-			segment = 0b00111111;
-			break;
-		case '1':
-			segment = 0b00000110;
-			break;
-		case '2':
-			segment = 0b01011011;
-			break;
-		case '3':
-			segment = 0b01001111;
-			break;
-		case '4':
-			segment = 0b01100110;
-			break;
-		case '5':
-			segment = 0b01101101;
-			break;
-		case '6':
-			segment = 0b01111101;
-			break;
-		case '7':
-			segment = 0b00000111;
-			break;
-		case '8':
-			segment = 0b01111111;
-			break;
-		case '9':
-			segment = 0b01101111;
-			break;
-		case 'a':
-			segment = 0b01011111;
-			break;
-		case 'b':
-			segment = 0b01111100;
-			break;
-		case 'c':
-			segment = 0b01011000;
-			break;
-		case 'd':
-			segment = 0b01011110;
-			break;
-		case 'e':
-			segment = 0b01111011;
-			break;
-		case 'f':
-			segment = 0b01110001;
-			break;
-		case 'g':
-			segment = 0b01101111;
-			break;
-		case 'h':
-			segment = 0b01110100;
-			break;
-		case 'i':
-			segment = 0b00010000;
-			break;
-		case 'j':
-			segment = 0b00001100;
-			break;
-		case 'k':
-			segment = 0b01110110;
-			break;
-		case 'l':
-			segment = 0b00110000;
-			break;
-		case 'm':
-			segment = 0b01010100;
-			break;
-		case 'n':
-			segment = 0b01010100;
-			break;
-		case 'o':
-			segment = 0b01011100;
-			break;
-		case 'p':
-			segment = 0b01110011;
-			break;
-		case 'q':
-			segment = 0b01100111;
-			break;
-		case 'r':
-			segment = 0b01010000;
-			break;
-		case 's':
-			segment = 0b01101101;
-			break;
-		case 't':
-			segment = 0b01111000;
-			break;
-		case 'u':
-			segment = 0b00011100;
-			break;
-		case 'v':
-			segment = 0b00011100;
-			break;
-		case 'w':
-			segment = 0b00011100;
-			break;
-		case 'x':
-			segment = 0b01110110;
-			break;
-		case 'y':
-			segment = 0b01101110;
-			break;
-		case 'z':
-			segment = 0b01011011;
-			break;
-		case 'A':
-			segment = 0b01110111;
-			break;
-		case 'B':
-			segment = 0b01111111;
-			break;
-		case 'C':
-			segment = 0b00111001;
-			break;
-		case 'D':
-			segment = 0b01011110;
-			break;
-		case 'E':
-			segment = 0b01111001;
-			break;
-		case 'F':
-			segment = 0b01110001;
-			break;
-		case 'G':
-			segment = 0b00111101;
-			break;
-		case 'H':
-			segment = 0b01110110;
-			break;
-		case 'I':
-			segment = 0b00110000;
-			break;
-		case 'J':
-			segment = 0b00011110;
-			break;
-		case 'K':
-			segment = 0b01110110;
-			break;
-		case 'L':
-			segment = 0b00111000;
-			break;
-		case 'M':
-			segment = 0b00110111;
-			break;
-		case 'N':
-			segment = 0b00110111;
-			break;
-		case 'O':
-			segment = 0b00111111;
-			break;
-		case 'P':
-			segment = 0b01110011;
-			break;
-		case 'Q':
-			segment = 0b01101011;
-			break;
-		case 'R':
-			segment = 0b00110011;
-			break;
-		case 'S':
-			segment = 0b01101101;
-			break;
-		case 'T':
-			segment = 0b01111000;
-			break;
-		case 'U':
-			segment = 0b00111110;
-			break;
-		case 'V':
-			segment = 0b00111110;
-			break;
-		case 'W':
-			segment = 0b00111110;
-			break;
-		case 'X':
-			segment = 0b01110110;
-			break;
-		case 'Y':
-			segment = 0b01101110;
-			break;
-		case 'Z':
-			segment = 0b01011011;
-			break;
-		case '_':
-			segment = 0b00001000;
-			break;
-		case '-':
-			segment = 0b01000000;
-			break;
-		case ' ':
-			segment = 0b00000000;
-			break;
-		case '\'':
-			segment = 0b00100000;
-			break;
-		case '"':
-			segment = 0b00100010;
-			break;
-		case '/':
-			segment = 0b01010010;
-			break;
-		case '\\':
-			segment = 0b01100100;
-			break;
-		case '=':
-			segment = 0b01001000;
-			break;
-		case ',':
-			segment = 0b00010000;
-			break;
-		case '>':
-			segment = 0b01001100;
-			break;
-		case '<':
-			segment = 0b01011000;
-			break;
-		case '(':
-		case '[':
-		case '{':
-			segment = 0b00111001;
-			break;
-		case ')':
-		case ']':
-		case '}':
-			segment = 0b00001111;
-			break;
-		case '@':
-			segment = 0b01111011;
-			break;
-		case '^':
-			segment = 0b00100011;
-			break;
-		case '`':
-			segment = 0b00000010;
-			break;
-		case '|':
-			segment = 0b00110000;
-			break;
-		case '~':
-			segment = 0b01000000;
-			break;
-		default:
-			segment = 0x00;
-	}
-	vfd_data[1] |= (segment<<(17)); // add the segment to memory
+	}	
+	if (((c&0x7f)<' ') || ((c&0x7f)>'~')) { // unknown ASCII character
+		vfd_data[1] |= (ascii_7segments[' '-' ']<<(17)); // add empty segments to memory
+	} else {
+		vfd_data[1] |= (ascii_7segments[c-' ']<<(17)); // add encoded segments to memory
+	}	
 	
 	vfd_data[2] = 0;
 }