Coding of the KY-58 signal processor is accomplished by using either a KOI-18 Tape Reader Device or a KYK-13 Automatic Transfer Device. In order to minimize damage to the connectors a fill cable is used to connect the devices to the KY-58.

The KOI-18 Tape Reader is a small, lightweight, battery-operated, hand-carried device for reading eight-level punched tape. The KOI-18 reads the tape and converts the information to a serial output. It can be used to load crypto-variables in a KY-58 or KYK-13. However, the KOI-18 is rarely used to load crypto-variables in aircraft on the flight line.

The KYK-13 Automatic Transfer Device (Figure 1-10-14) is the common device used to key crypto equipment in the aircraft. It is a small, lightweight, battery-operated unit. The device contains six addressable storage registers that allow storage of a variety of crypto-variable codes in the device. The KYK-13 contains the following controls and indicators:

a. FILL Switch. This switch is used to address the six individual storage registers or zeroizing all six registers.

b. MODE Switch. This switch is used to turn the KYK-13 ON and OFF, or to zeroize one or all of the registers in the device.

c. INITIATE Button. This button is used to transfer a crypto-variable code in a storage register or to check the status of a register when the KYK-13 mode switch is selected OFF.

d. PARITY Light Indicator. This light indicates the presence of a valid crypto-variable code in a register when the INITIATE button is pressed. During crypto-variable loading, it indicates that the crypto-variable was transferred successfully to the equipment and passed the parity check.