Ship Engines +

#engines +positive input
alias MemEngUpDown d0 #-101 +101
alias MemEngNS d1
alias MemEngWE d2
# output
alias EnginesUp d3
alias EnginesN d4
alias EnginesE d5

alias EngUp r1
alias EngN r2
alias EngE r3
alias ThrustMod r4

Start:
l ThrustMod db Setting #modifier from dial

UpDown:
l EngUp MemEngUpDown Setting
brgtz EngUp 3 #use if input > 0
s EnginesUp Setting 0 #zero/neg is zero
j NS
mul EngUp EngUp ThrustMod #modifier of thrust
s EnginesUp Setting EngUp

NS:
l EngN MemEngNS Setting
brgtz EngN 3 #use if input > 0
s EnginesN Setting 0 #zero/neg is zero
j WE
mul EngN EngN ThrustMod #modifier of thrust
s EnginesN Setting EngN

WE:
l EngE MemEngWE Setting
brgtz EngE 3 #use if input > 0
s EnginesE Setting 0 #zero/neg is zero
j Tick
mul EngE EngE ThrustMod #modifier of thrust
s EnginesE Setting EngE

Tick:
yield
j Start