Creating a basic Multitasking Envi

Hello,
it's me again.

I'm still trying to create an basic Multitasking OS and i want to ask 2 things:

1.
I create a table with coroutines like this

local currentProg = 1

routines = {}

function createNewInstance(program)
 table.insert(coroutine.create(
 function n()
  shell.run(program)
 end
))
 currentProg = table.getn(routines)
end

Where i add my programs that i'm running and it worked perfectly but my 2nd question is:

I need to buffer those programs.. like every program has it's own buffer which is wrapable and can be displayed on demand.

Can you give me an API like this.

Thankful PrinzJuliano