local function myFunc(myArg)
        for i = 1, myArg do
                print(i)
                sleep(1)
        end
end

-- From bios.lua, we have the source of sleep:
-- function sleep( nTime )
--     local timer = os.startTimer( nTime or 0 )
--     repeat
--         local sEvent, param = os.pullEvent( "timer" )
--     until param == timer
-- end

-- ... and the source of os.pullEvent():
-- function os.pullEvent( sFilter )
--     local eventData = { os.pullEventRaw( sFilter ) }
--     if eventData[1] == "terminate" then
--         error( "Terminated", 0 )
--     end
--     return table.unpack( eventData )
-- end

-- ... and the source of os.pullEventRaw():
-- function os.pullEventRaw( sFilter )
--     return coroutine.yield( sFilter )
-- end

-- So, os.pullEvent( "timer" ) == coroutine.yield( "timer" ), but errors if a terminate event is returned instead.
-- Now let's run myFunc as a coroutine:

-- Initialise coroutine:
print("Starting coroutine!")

local myCoroutine = coroutine.create(myFunc)
local ok, requestedEvent = coroutine.resume(myCoroutine, 10)  -- Being the first resume, 10 gets pushed to myArg.

-- Run coroutine to completion:
while coroutine.status(myCoroutine) ~= "dead" do
        print("Coroutine seems ok, and is asking for a \"" .. requestedEvent .. "\" event.")  -- With the example myFunc, "requestedEvent" will always be "timer".

        local myEvent = {os.pullEvent(requestedEvent)}
        ok, requestedEvent = coroutine.resume(myCoroutine, unpack(myEvent))  -- Parameters of later resumes are returned by coroutine.yield() (and hence os.pullEvent()) within the coroutine itself.
end

-- Coroutine has finished execution.
if ok then
        print("Coroutine has completed in a natural manner.")
else
        print("Coroutine errored!: " .. requestedEvent)
end