I'm sure you will get there with this.
I stopped designing things around PCs a long time ago because it very quickly became obvious to me that the speed of obsolescence and the overall dodgy reliability meant than anything built around a PC will have a limited life.
You are finding this out - having to scrounge around to find a laptop that has a serial port etc etc etc.
PC's just are not suited to embedded systems as used in all early pinballs - they are still 100% repairable but I don't like to think about the newer stuff using PC's - we are going to see a lot of it parted out long before it should be......
