(a) Describe the internal structure of a generalised RAM memory device using a block diagram. Indicate the purpose of the signals within the device and those which connect to external circuits. [6 marks] (b) Identify the two main types of RAM and for each sketch the circuit diagram of its memory cell and briefly describe the mechanism of a typical read and write operation. [8 marks] (c) Name the different types of FLASH memory and compare the differences between them. [6 marks)