This lookup table should make it convenient when you need to translate hex, binary, or decimal numbers. The first column lists the decimal numbers between 1 and 255. The second column is the hexadecimal equivalent. The third column is the decimal equivalent of a hex most significant byte or "MSB." The fourth column is the binary.

     If you need to find out the decimal equivalent of the hex number $FD l5, look up $FD in the MSB column and you'll see that it's 64768. Then look up the $15 in the LSB column (it's 21 decimal) and add 21 + 64768 to get the answer: 64789.

     Going the other way, from decimal to hex, you could translate 64780 into hex by looking in the MSB column for the closest number (it must be smaller, however). In this case, the closest smaller number is 64768 so jot down $FD as the hex MSB. Then subtract 64768 from 64780 to get the LSB: 12. Look up 12 in the decimal column (it is $0C hex) and put the $FD MSB together with the $0C LSB for your answer: $FD0C.

     With a little practice, you can use this chart for fairly quick conversions between the number systems. Most of your translations will only involve going from hex to decimal or vice versa with the LSB of hex numbers, the first 255 numbers, which require no addition or subtraction. Just look them up in the table.

Table E- 1.

Decimal

Hex (LSB)

Hex (MSB)

Binary

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255

01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F 40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F 50 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F 60 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F 70 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F 80 81 82 83 84 85 86 87 88 89 8A 8B 8C 8D 8E 8F 90 91 92 93 94 95 96 97 98 99 9A 9B 9C 9D 9E 9F A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 AA AB AC AD AE AF B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 BA BB BC BD BE BF C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 CA CB CC CD CE CF D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 DA DB DC DD DE DF E0 E1 E2 E3 E4 E5 E6 E7 E8 E9 EA EB EC ED EE EF F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 FA FB FC FD FE FF

256 512 768 1024 1280 1536 1792 2048 2304 2560 2816 3072 3328 3584 3840 4096 4352 4608 4864 5120 5376 5632 5888 6144 6400 6656 6912 7168 7424 7680 7936 8192 8448 8704 8960 9216 9472 9728 9984 10240 10496 10752 11008 11264 11520 11776 12032 12288 12544 12800 13056 13312 13568 13824 14080 14336 14592 14848 15104 15360 15616 15872 16128 16384 16640 16896 17152 17408 17664 17920 18176 18432 18688 18944 19200 19456 19712 19968 20224 20480 20736 20992 21248 21504 21760 22016 22272 22528 22784 23040 23296 23552 23808 24064 24320 24576 24832 25088 25344 25600 25856 26112 26368 26624 26880 27136 27392 27648 27904 28160 28416 28672 28928 29184 29440 29696 29952 30208 30464 30720 30976 31232 31488 31744 32000 32256 32512 32768 33024 33280 33536 33792 34048 34304 34560 34816 35072 35328 35584 35840 36096 36352 36608 36864 37120 37376 37632 37888 38144 38400 38656 38912 39168 39424 39680 39936 40192 40448 40704 40960 41216 41472 41728 41984 42240 42496 42752 43008 43264 43520 43776 44032 44288 44544 44800 45056 45312 45568 45824 46080 46336 46592 46848 47104 47360 47616 47872 48128 48384 48640 48896 49152 49408 49664 49920 50176 50432 50688 50944 51200 51456 51712 51968 52224 52480 52736 52992 53248 53504 53760 54016 54272 54528 54784 55040 55296 55552 55808 56064 56320 56576 56832 57088 57344 57600 57856 58112 58368 58624 58880 59136 59392 59648 59904 60160 60416 60672 60928 61184 61440 61696 61952 62208 62464 62720 62976 63232 63488 63744 64000 64256 64512 64768 65024 65280

00000001 00000010 00000011 00000100 00000101 00000110 00000111 00001000 00001001 00001010 00001011 00001100 00001101 00001110 00001111 00010000 00010001 00010010 00010011 00010100 00010101 00010110 00010111 00011000 00011001 00011010 00011011 00011100 00011101 00011110 00011111 00100000 00100001 00100010 00100011 00100100 00100101 00100110 00100111 00101000 00101001 00101010 00101011 00101100 00101101 00101110 00101111 00110000 00110001 00110010 00110011 00110100 00110101 00110110 00110111 00111000 00111001 00111010 00111011 00111100 00111101 00111110 00111111 01000000 01000001 01000010 01000011 01000100 01000101 01000110 01000111 01001000 01001001 01001010 01001011 01001100 01001101 01001110 01001111 01010000 01010001 01010010 01010011 01010100 01010101 01010110 01010111 01011000 01011001 01011010 01011011 01011100 01011101 01011110 01011111 01100000 01100001 01100010 01100011 01100100 01100101 01100110 01100111 01101000 01101001 01101010 01101011 01101100 01101101 01101110 01101111 01110000 01110001 01110010 01110011 01110100 01110101 01110110 01110111 01111000 01111001 01111010 01111011 01111100 01111101 01111110 01111111 10000000 10000001 10000010 10000011 10000100 10000101 10000110 10000111 10001000 10001001 10001010 10001011 10001100 10001101 10001110 10001111 10010000 10010001 10010010 10010011 10010100 10010101 10010110 10010111 10011000 10011001 10011010 10011011 10011100 10011101 10011110 10011111 10100000 10100001 10100010 10100011 10100100 10100101 10100110 10100111 10101000 10101001 10101010 10101011 10101100 10101101 10101110 10101111 10110000 10110001 10110010 10110011 10110100 10110101 10110110 10110111 10111000 10111001 10111010 10111011 10111100 10111101 10111110 10111111 11000000 11000001 11000010 11000011 11000100 11000101 11000110 11000111 11001000 11001001 11001010 11001011 11001100 11001101 11001110 11001111 11010000 11010001 11010010 11010011 11010100 11010101 11010110 11010111 11011000 11011001 11011010 11011011 11011100 11011101 11011110 11011111 11100000 11100001 11100010 11100011 11100100 11100101 11100110 11100111 11101000 11101001 11101010 11101011 11101100 11101101 11101110 11101111 11110000 11110001 11110010 11110011 11110100 11110101 11110110 11110111 11111000 11111001 11111010 11111011 11111100 11111101 11111110 11111111

     The following program will print copies of this number table. You might need to make some adjustments to the printout conventions of your computer's BASIC and your printer itself. This program is for Microsoft BASIC and will not work on the Atari.

Program E-1 . Microsoft Table Printer.

10 OPEN4,4:REM OPEN CHANNEL TO PRINTER
100 HE$="0123456789ABCDEF"
110 FORX=1TO255
120 B=2:C=1
122 IFX<10THENPRINT#4,"  ";:GOTO130
124 IFX<100THENPRINT#4," ";
130 PRINT#4,X;" ";:DE=X:GOSUB240
135 REM CREATE BINARY
140 IFXAND1THENK$(C)="1":GOTO160
150 K$(C)="0"
160 C=C+1:IFBANDXTHENK$(C)="1":GOTO180
170 K$(C)="0"
180 B=B*2:IFC>8THEN200
190 GOTO160
200 FORI=8TO1STEP-1:PRINT#4,K$(I);:NEXTI
220 PRINT#4:NEXTX
230 END:REM TRANSFORM TO HEX
240 H$="":FORM=1TO0STEP-1:N%=DE/(16^M):DE=DE
    -N%*16^M
250 H$=H$+MID$(HE$,N%+1,1):NEXT
260 PRINT#4,H$" ";:DE=X*256
262 IFDE<1000THENPRINT#4," ";:GOTO270
264 IFDE<10000THENPRINT#4," ";
270 PRINT#4,DE" ";:RETURN