C:\AVRDude_5.8>avrdude -c usbasp -p t13 -B 8
avrdude: set SCK frequency to 93.75 kHz
avrdude: warning: cannot set sck period. please check for usbasp firmware update.
avrdude: error: programm enable: target doesn't answer. 1
avrdude: initialization failed, rc=-1
Double check connections and try again, or use -F to override
avrdude done. Thank you.