8 bytes for:    B,C,D,E,H,L,F,A

8 bytes for:    B',C',D',E',H',L',F',A'
 
8 bytes for:    IX, IY, SP, PC

1 byte for:     (PC)    (*last* loaded instruction byte)

2 bytes for:    R, I

1 byte for:     4 bits:  IFF0,IFF1,IFF2, HALT-pin-status
                2 bit:   IM (interrupt mode)
                1 bit:   NMI-flipflop
                1 bit:   stray DD/FD code

4 bytes for:    tick counter  (unsigned long)
