The first problem is an example. Break the register contents into bytes (2 hex digits). All numbers are in hex! Instruction add ax, cx After AX: 02 17 CX: 01 A2 Before Ex. AX00 75 CX: 01 A2 sub eax, ecx EAX: ECX: EAX: 00 00 03 75 ECX: 00 00 01 A2 AX CX AX: 77 AC add ax, cx CX: 4B 35 EAX: ECX EAX: 00 00 00 75 sub ecx, eax ECX: 00 00 01 A2 BL: 4B DX: FF 20 4 add bl, 4 BL: ?? Value sub dx, Value Word at value: FF 20 EAX: 00 00 00 09 ECX: 00 00 01 A2 add eax, 1 EAX inc ecx ECX