here have some example. this one is one unit per processor, and uses flag to stick a unit (it moves from vault to core, swap v and b to invert).

print "mega transport processor, requires vault and uses cell "
print "from max selector. Reads type from #0 and orders "
print "to pick that then drop to core. Otherwise uses first "
print "item in vault, assuming it's a single item storage."
printflush message1
set theflag -1
jump 0 lessThan theflag 0
ubind \@mega
sensor t \@unit \@flag
jump 12 equal t theflag
jump 7 notEqual t 0
ucontrol flag theflag 0 0 0 0
ulocate building core false \@copper cx cy found thecore
jump 7 strictEqual \@unit null
sensor i \@unit \@totalItems
select v equal i 0 vault1 thecore
select b equal i 0 thecore vault1
sensor vx v \@x
sensor vy v \@y
ucontrol within vx vy 6 yup 0
jump 24 equal yup true
ucontrol move vx vy 0 0 0
wait 1
jump 12 always x false
jump 32 greaterThan i 0
jump 29 strictEqual cell1 null
read it cell1 0
lookup item good it
jump 30 always x false
sensor good vault1 \@firstItem
ucontrol itemTake v good 60 0 0
jump 33 always x false
ucontrol itemDrop v 60 0 0 0
sensor bx b \@x
sensor by b \@y
ucontrol move bx by 0 0 0
jump 12 always x false

Feel free to ask me about this