                                    Type Casts
                                    
These are opcodes 66h and 67h.

These opcode only apply to 386+ Processors.

Starting with the 386 Processor, They extended the 16 Bit registers from
16 bit to 32 bit.  Instead of making hunderds more opcodes, they invented the
type cast.


66h Typecasts a register.

Example:
Real Mode:
 MOV AX, 10h
 
 In real mode is:
 B81000h
 
 But, in Pmode the default register is 32 bit, so the same instruction in pmode is:
 66B810000h
 
 
 MOV EAX, 10h
 In Real Mode is:
 66B810000000h
 
 In Pmode is:
 B810000000h
 
 
 67h is for typecasting pointers. I.E., in Pmode, Addressing (Offsets) are 32 bit, but
 in real mode addresses are 16 bit.  So, putting a 67h infront of the instruction will
 type cast it's address to the opposite mode.  Makes it a 32 bit address in Real mode
 and a 16 bit address in pmode.
 
 
 
 
 
 
 
 
