An image pickup apparatus is disclosed which prevents interference of a lens barrel with an optical member and so forth with certainty and is advantageous in achievement of reduction in scale, weight and cost of the optical member and an adapter ring. A plurality of requests are received from a client, each request of the plurality of requests having assigned a unique sequence number, each request being an inputoutput request to a data storage device. The cutting head assembly also has a plate having a plate keyway that slidably engages the platform key. The customized modules are operable to selectively access and process a number of the modules using the API library while the customized modules are processing on the portable electronic device. During a single clock cycle, the system writes stored data from a refresh buffer into a row in the memory array and then reads data from one row of the memory array into the buffer.