In addition to all the other answers, doing some procedural thought exercises may help. He can practice breaking down complex actions into more basic instructions. For example, thinking through what steps he takes to walk to a meal. He can start at a high level of just the turns and distances to walk, then think through what he actually does to take a step, or make a turn, or sit down or stand. It may not seem like much, but it will train him to think about how to build out instructions at different levels of abstraction, which will make a significant dent in the learning curve once he does gain access to a computer.