title: MUL instruction in 8086
body: <p>** <strong>LONG VERSION OF QUESTION</strong>:when i check the manual for 8086 instruction set, specifically the MUL instruction, i see that the operand can be in a register (8 or 16 bits) or it can be in memory (also 8 or 16 bit). knowing that 8086 uses AX as accumulator if the operand is 16 bit , and AL (8-bit) if the operand is 8 bit .. how does it know what size is the operand if the operand is in memory??</p>
  
  <p>** <strong>SHORT VERSION OF QUESTION</strong>: how does 8086 know if operand is 16 or 8 bits in the following instruction : MUL [1234H] </p>