I don't loading program in my 1261, because at cload command, pocket is blocked and busy signal appear, where is problem please ?

Hi Thierry

When you type Cload it is normal that the busy signal appears. The pocket is waiting for an input. In case no input is received the 1261 remains busy so you have to press "Break".
If the 1261 is locked it's because something wrong happened with the input signal (reversed polarity, inappropriate voltage, unexpected signal to other pins, etc...). Please tell us what kind of peripheral you use with the PC-1261.

All the best
Pierre