A system is provided for controlling the delay in an isolation buffer. The adapter has a main body, a first mechanical coupling capable of removably coupling the electronic device to the adapter, and a second mechanical coupling capable of removably coupling the adapter to the host. Page images are labeled with numbers that are determined to be most likely to represent the actual page number. The well layer is formed of GaN1\u2212x\u2212y\u2212zAsxPySbz, and the barrier layer is formed of a nitride semiconductor containing In. A first or second transmission unit transmits a received signal posterior or prior to the known symbol part to a first or second memory in a forward direction or reverse order.