x86

ax      ; accumulator
bx      ; address
cx      ; counter
dx      ; 32bit extension of ax
si      ; source address
di      ; destination address
bp      ; base pointer
sp      ; stack pointer
ip      ; instruction pointer
ss      ; stack segment
flags

int      ; interruption (call service vector)
je       ; jump if equal
jz       ; jump if zero
jmp      ; jump always
pop      ; restore data from stack
push     ; save data into stack
test     ; test register mask or zero

xor      ; ^
or       ; |
and      ; &
not      ; !
neg      ; ~
shl      ; <<
shr      ; >>
sal      ; signed shift left
sar      ; signed shift right

add      ; add eax, ebx       ; eax += ebx
sub      ; sub eax, ebx       ; eax -= ebx
inc      ; increment by one
dec      ; decrement by one

; unsigned
div      ; div bl             ; al = ax / bl     // quotient
                              ; ah = ax % bl     // remainder
mul      ; mul bl             ; ax = al * bl

; signed
idiv     ; signed
imul     ; signed

call label_name ; push address of next instruction
                ; then jump to label_name
ret             ; pop return address then jump to it

cmp
in
nop
rcl
rcr
rol
ror
sar
shl
sal
shr

Addressing modes

[bx]
[mem]
[si]
[di]
[bx+si]
[bx+di]
[bp+si]
[bp+di]

[bx+d8]
[bp+d8]
[si+d8]
[di+d8]
[bx+si+d8]
[bx+di+d8]
[bp+si+d8]
[bp+di+d8]

[bx+d16]
[bp+d16]
[si+d16]
[di+d16]
[bx+si+d16]
[bx+di+d16]
[bp+si+d16]
[bp+di+d16]

Jump instructions

je  d8
jz  d8

jne d8
jnz d8

jc  d8
jb  d8

jnc d8
jae d8

jbe d8
ja  d8

jl  d8
jg  d8
jle d8
jge d8

js  d8
jns d8

jpe d8
jpo d8

jo  d8
jno d8

jcxz d8        ; if cx == 0 then jump

loop d8

; loop repeats until cx is 0
; for (cx = 80 ;cx > 0; cx -= 1) {
;     scroll_scenery();
; }

   mov cx, 80
fb1:
   push cx
   call scroll_scenery
   pop cx
   loop fb1

New

cbw       ; convert byte to word, sign extend

lds
les

Strings

std       ; set direction flag for decrementing string operations
cld       ; clear direction flag
stosb     ; store byte ; *(es+di) = al; di += 1
stosw     ; store word ; *(es+di) = ax; di += 2

lodsb     ; ax = *(ds+si); si += 1
lodsw     ; ax = *(ds+si); si += 2

cs lodsb  ; ax = *(cs+si); si += 1
cs lodsw  ; ax = *(cs+si); si += 2

pushf     ; push flags
popf      ; retore flags