‰  NOW 35 WPM  ‰  TEXT IS FROM OCTOBER 2012 QST  PAGE 42‰

CONSTRUCTED IN BINARY CODED DECIMAL BCD FORMAT WITH THE FIRST NIBBLE 4 BITS
OF THE BYTE CONTAINING THE FIRST DECIMAL DIGIT 0 9, AND THE SECOND NIBBLE
OF THE BYTE CONTAINING THE SECOND DECIMAL DIGIT.  THE COMBINATION OF THE
TWO NIBBLES, A BYTE, IN TURN IS CONVERTED TO A SINGLE DECIMAL VALUE FOR
TRANSMISSION.  WHILE THIS CAN BE INTIMIDATING FOR THE COMPUTER NOVICE, MY
POINT IS TO ILLUSTRATE THAT IT WILL TAKE SOME THOUGHT AND STUDY TO
UNDERSTAND THE FORMATS USED BY BOTH THE CONTROLLING SOFTWARE AND THE RADIO
BEING USED.  HERE IS AN EXAMPLE.  LETS ASSUME THE CONTROLLING SOFTWARE IS
SENDING A FREQUENCY OF 435R345 MHZ TO THE RADIO.  THE FIRST TWO DECIMAL
DIGITS OF THE FREQUENCY 43 ARE CONVERTED INTO BCD.  THE BINARY CODE FOR 4
IS 0100.  THE BINARY CODE FOR 3 IS 0011.  PUTTING THE FIRST DECIMAL DIGIT
INTO THE HIGH NIBBLE AND THE SECOND DECIMAL DIGIT INTO THE LOW NIBBLE
CREATES THE BYTE 0100 0011 OR 0X43 HEXADECIMAL OR 67 DECIMAL 0X INDICATES
HEXADECIMAL.  YOU CAN USE THE SCIENTIFIC CALCULATOR THAT IS AN ACCESSORY TO
WINDOWS TO CONVERT FROM ONE NUMBERING SYSTEM TO ANOTHER.  I USE IT ALL THE
TIME.  A SAMPLE OF THE RELEVANT FT 817 COMMANDS FOR THIS PROJECT IS
CONTAINED IN TABLE 2.  THE COMMAND FORMAT TO SET THE FREQUENCY TO THE RADIO
IS P1P2P3P401 WHERE THE P S MAKE UP THE FREQUENCY IN BCD, THE 0X01 IS THE
HEXADECIMAL OPCODE TO SET THE FREQUENCY.  TRANSLATING THIS INTO HEXADECIMAL
‰  END OF 35 WPM TEXT  ‰  QST DE W1AW  ƒ