These octal bus transceivers are designed for asynchronous two-way communication between data buses. The control-function implementation minimizes external timing requirements. The devices allow data transmission from the A bus to the B bus or from the B bus to the A bus, depending upon the logic level at the direction-control (DIR) input. The output-enable (OE)\ input can be used to disable the device so that the buses are effectively isolated. The -1 version of the SN74ALS245A is identical to the standard version, except that the recommended maximum IOL is increased to 48 mA. There is no -1 version of the SN54ALS245A.