accumulated a processing routine for reading out the accumulated key codes is executed in this processing routine the key codes are read out on 34 first in first out 34 basis in accordance with the fifo list in buffer 14 thus since the key codes of both the keyboard 1 15 and the keyboard 2 16 are stored in the input buffer 14 the order of the key codes stored in the input buffer 14 corresponds with the order in time in which keys were pressed for example in fig2 the key code of the keyboard 1 15 is first read out and then the key code of the keyboard 2 16 is read out of fifo buffer 14 an operation of an auto repeat key processing will now be described in conjunction with a flow chart shown in fig3 prior to the operation a control flag 121 is cleared to zero for an initialization step 30 then assuming that an auto repeat key is pressed on the keyboard 1 15 it is regarded as a first auto repeat key because a value of control flag 121 is zero then the key is accepted step 34 the flag is set to 34 1 34 step 35 and a code allocated to the key is stored in the key code memory 122 step 36 then as to the keys output from the keyboard after that they are checked whether they are the auto repeat keys step 31 u2192 32 if they are the auto repeat keys a state of the flag is further checked step 33 when the same auto repeat key is successively output from the keyboard 1 15 and the control flag 121 has been set to 34 1 34 in.