It's from his modchip that most other modchips are derived from in some sense. Surprisingly, The Old Crow specializes in electronic music synthesizers, not hacking video game consoles.
The first "open source" modchip was reverse engineered by a guy named "The Old Crow". Modchips that work under these updated circumstances are known as "stealth modchips" because the console shouldn't be able to detect them at all. However, modern modchips already deal with this. This causes the PS1 to believe that whatever disc is inside is legitimate and proceed to boot up. PSX modchips work by electrically stifling the output originally generated by whatever CD is inside the drive and then injecting a new, faked signal into the CD microcontroller. If you are looking for them I am selling flashed, prewired modchips. So why keep an old console? Turns out the answer is nostalgia and memories. I remember some games wouldn't load anymore and I had gotten a PS2. Fast-forward to today and I no longer have my original PS1. They say the apple doesn't fall far from the tree. He modded my PS1 to have a little switch in the back that would allow it to play burnt games.
While I wasn't smart enough to mod game consoles when I was young, my dad wasn't bad at it.
I can trace the history of how I got involved in computers back to playing and modding video games. It was one of the first, if not the first, game consoles I owned and it had a profound effect on my future.