EEPROM contents are copied to the SRAM memory of the main CPU at startup. Every block is 32 bytes long when using a 24C64: Blocks 0 to 99 are the 99 memory channels: xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx (xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx xx) VA Fl Fh Sl Sh F1 TQ VA = 00=Empty / 01=Available / 02=Available but skip while scanning Fl = Frequency LSB - The working freq is 5kHz or 6.25kHz multiplied by this value Fh = Frequency MSB / Sl = Shift LSB - The shift is 5kHz or 6.25kHz multiplied by this value Sh = Shift MSB / F1 = Flag bits: 10 = Channel spacing multiplier (0 to 3) 2 = 5kHz space(0) / 6.25kHz space(1) 3 = Mixing type: VCO=IF-Freq(0) / VCO=IF+Freq(1) 54 = Shift, 0=none 1=Positive 2=Negative 7 = VCO from 300 to 500(1) / 430 to 440(0) TQ = CTCSS transmit number The remaining is the name of the channel, only 9 characters for 24C16 100 Call channel Same structure. 101 Tone squelch RX 102 Own selcall code 103 Callsign 114 Tone squelch TX 115 Selcall reply code 104 Selcall memory code 0 105 Selcall memory code 1 106 Selcall memory code 2 107 Selcall memory code 3 108 Selcall memory code 4 109 Selcall memory code 5 110 Selcall memory code 6 111 Selcall memory code 7 112 Selcall memory code 8 113 Selcall memory code 9 116 Selcall memory name 0 117 Selcall memory name 1 118 Selcall memory name 2 119 Selcall memory name 3 120 Selcall memory name 4 121 Selcall memory name 5 122 Selcall memory name 6 123 Selcall memory name 7 124 Selcall memory name 8 125 Selcall memory name 9 Every number in a selcall block can be 0 to 31, from 16 the number is a DTMF number: 1111111111222222222233 01234567890123456789012345678901 0123456789HTRA 0123456789*#ABCD The names in the selblock calls and memory channels will end with a zero