If I understand you correctly, you want to take the screen from one of your PSPs and use it as the display for your PS One. While that is technically possible (that's basically what I did in the video) it is probably not worth the trouble. You can get the screen add-on for the PS One on Ebay for under $100 and it even has speakers. On the other hand what you see in the video is a combination of 3 boards. One is converting the composite video to a digital signal. This is then converted using another board (DE0-Nano) and the output goes to a third board which powers the the screen. It's a great way to get into signal processing and FPGA programming, but as a first time electronics project it's got a very steep learning curve. If you are hell-bent on using your existing screen you should try and find an existing board that does all the heavy lifting for you. Maybe go to a site like aliexpress and search for 'TFT/LCD driver board'. You'd want one that has a composite video input and a parallel LCD output (preferably directly mentioning the Sharp display of your PSP). Hope this helps.