The computer would have to work with the other device. You can't patent simple combinations, such as a pen with a bottle opener. If you pass that test, you may be tempted to apply for a patent. You can do it yourself, but, like the other items on your list, it takes a long time to learn. Patent lawyers will be happy to take your money, but you will never find one willing to work on contingency. They know that they go years without seeing a client make money. One that I knew forgot that, and patented his own idea. Then he lost $4mil. trying to make and sell the thing.
It takes, on average, $14mil. pa in gross sales to break even on the legal work to maintain one patent.
Corporations, normally quite rational beasts, go berserk around patents. They will budget ten times more to break yours than the royalties you ask for. If there are large companies involved in your product line, your best options are to either take a job there, or publish everything until they hire you to shut up.
If your product is a small niche item, or lends itself to personalization, one trick is to just file one cheap paper so you can say "Patent Pending." This will scare off most of the little pirates. Then you focus on development and sales. When the copycats come out, you are ready with a better version, and you are known as the best.
If you are an aspie, you probably need to find a business partner to deal with most of these issues. Every successful business needs a team anyway.