Convert the following from hex to binary and draw it on the memory map.

    RAM    = 0000 -> 00FF
    EPROM = FF00  -> FFFF

Answer:

  0000  0000 0000  0000 (0)    RAM start

  0000  0000  1111  1111 (255 byte)  RAM stop

  1111  1111  0000  0000 (63.75K)   Eprom start

  1111  1111  1111  1111 (64K)   Eprom stop
 
  The memory map is shown below:-

  Due to the tri-state nature of the I.C's (Ram, Rom etc.) they may be placed in parallel and 'turned on ' when they are required. This process is termed decoding. There are two types of   decoding:-
 
    1. Partial decoding
    2. Absolute decoding