Two Gigabytes

RAM was still a major issue even then. The PS1 had 2MB of RAM, and we had to do crazy things to get the game to fit. We had levels with over 10MB of data in them, and this had to be paged in and out dynamically, without any “hitches”—loading lags where the frame rate would drop below 30 Hz.  – Quora

The original PlayStation was released in 1997. My iPhone in 2015. One has 2GB of RAM, the other a thousand times less. Astonishing. 

Update: apparently the iPhone 6 only has 1GB of RAM. Even so, astonishing.