IIRC Apple originally invested in ARM during the development of the Newton. The original Newtons used ARM 610 CPUs. I don't know exactly when they sold their ARM stake but they kept their architecture license.
The Newton was long before the iPaq, the MessagePad was released in 1993.
Q> And latter - was it that it looked that Apple maybe in danger of going under, and then they sold their ARM stake and got a cash injection that way?
A> And yes. In the late-1990s turnaround, Apple sold down its ARM stake in multiple tranches after ARM’s 1998 IPO, realizing hundreds of millions of dollars that helped shore up finances (alongside the well-known $150 million Microsoft deal in Aug 1997).
The Newton was long before the iPaq, the MessagePad was released in 1993.