> Consider the 256 GB memory iPhone X: Implemented in vacuum tubes in 1957, the transistors in an iPhoneX alone would have [cost]...

Did a search for computer history and 1957 and came up with this: http://www.computerhistory.org/timeline/1957/

...the creation of FORTRAN? Looking at the entry for 1956, the site lists MIT creating the TX-0, the "first general-purpose programmable computer built with transistors", and IBM's shipment of "RAMAC", the first computer based on "The new technology of the hard disk drive".

It's where the historical data of memory prices start on his source: http://jcmit.net/memoryprice.htm

In the mid 50s silicon transistors started to replace vacuum tubes. I assume tubes were at their cheapest in the late 50s. I'm not sure why the article uses '57 in particular though.

So that Steve jobs was at least 2 years old before he came up with the idea