card error :(

Hello skyther Hello everyone! So I assembled the device, and it swears. First it writes "C_er", then "b_er". The hardware is as follows: mega16, quartz 14.318 (the spec works from it). Is the quartz frequency critical? Maybe I'm formatting the card wrong, like FAT16? Files were written to the root with original names, and with digital names (1.txz, 01.tzx, 001...). The card is seen by the reader and the SL45 phone. This is the situation that do you recommend?