local delta=0x30-0x1A
while true do
    --memory.writebyte(0x8030E3,3)      --No enemies.

    if memory.readbyte(0x404024)>0 then     --If a shot's been fired...
        for i=0,4 do
            memory.writebyte(0x40401A+i*delta,memory.readbyte(0x40401A))
            memory.writebyte(0x40401D+i*delta,memory.readbyte(0x40401D))
        end
    end

    while memory.readbyte(0x404024)>0 do
        --memory.writebyte(0x8030E3,3)      --No enemies.

        local timer=memory.readbyte(0x404024)
        for i=0,4 do
            memory.writebyte(0x404024+i*delta,timer)
            lastx=memory.readbyte(0x40401A+i*delta)
            memory.writebyte(0x40401A+i*delta,math.min(math.max(lastx+i-2,0),255))
            memory.writebyte(0x404016+i*delta,2)
            memory.writebyte(0x40401E+i*delta,0)
        end
        emu.frameadvance()
    end

    --memory.writebyte(0x4035E5,150)    --Also star's y position, but also gets confused
    --memory.writebyte(0x403808,80)     --Also star's y position, but gets confused when other shots fired
    memory.writebyte(0x40401D,150)      --Star's y position
    --memory.writebyte(0x803072,120)        --No effect (?)
    --memory.writebyte(0x404024,30)     --Counts down to star's disappearance
    emu.frameadvance()
end

--[[
STAR 1
------
x position:
s0401A

y positions:
s035E5
s03808
s0401D

countdown to disappearance:
s04024

no effect?
i03072

**************
STAR 2
------
x position:
s04030

y position:
s04033

**************
Other addresses of interest:
s04030
]]--