-- r1 will be the temp in fahrenheit
-- r2 temp in celsius 
-- r3/r4/r5 will be used by constants

-- (f - 32) * 5 / 9

li r1, 100

li r3, 32
li r4, 5
li r5, 9

sub r2, r1, r3
mul r2, r2, r4
dir r2, r0, r2, r5
tx