Another way you could do it is to put in a timer() based delay, like this:
NextMove = timer() + 20
do
if timer() > NextMove
sprite 317,x1,y1,1
if keystate(200) then y1=y1-1
if keystate(208) then y1=y1+1
if keystate(203) then x1=x1-1
if keystate(205) then x1=x1+1
NextMove = timer() + 20
endif
loop
or you could simply put in a wait 10 command. Still another way would be to set a SYNC rate that is slower. It appears that you are running without manually SYNCing, so it would default to 0, which is as fast as the host computer can run it. Here is an example of manually syncing:
sync on : sync rate 60
ink rgb(255,0,255),0
box 0,0,64,64
get image 1,0,0,64,64
x1 = 200 : y1 = 200
do
sprite 317,x1,y1,1
if keystate(200) then y1=y1-1
if keystate(208) then y1=y1+1
if keystate(203) then x1=x1-1
if keystate(205) then x1=x1+1
sync
loop
So many games to code.....so little time.