The CPU of a system having 1 MIPS execution rate needs 4 machine cycles on an average for executing an instruction. The fifty percent of the cycles use memory bus. A memory read/ write employs one machine cycle. For execution of the programs, the system utilizes 90 percent of the CPU time. For block data transfer, an IO device is attached to the system while CPU executes the background programs continuously. What is the maximum IO data transfer rate if programmed IO data transfer technique is used?

A microinstruction format has microoperation field which is divided into 2 subfields F1 and F2. Each having 15 distinct micro operations condition field CD for four status bits. Branch field BR having four options used in conjunction with address field AD. The address space is of 128 memory words. The size of micro instruction is