TYPO?

[SlideRule]

An excerpt from PDAs: Revolutionizing The Way We Learn and Teach , Turkish Online Journal of Distance Education-TOJDE April 2006 ISSN 1302-6488 Volume:7 Number:2 Article:14 pages 153-154

TECHNOLOGIES AND INFRASTRUCTURE
PDAs have evolved over the last two decades starting in 1974 with Hewlett Packer’s release of the HP-45 calculator, which could be programmed¹, included a timer², and had removable storage³.
?¹ ?² ?³

BEST!
SlideRule
ps: yes, there is an embedded tyypo, but the Subject: TYPO? refers to ?¹ & ?³!

[KeithB]

Have them change it, we can't have things *wrong* on the internet!
https://xkcd.com/386/

[rprosperi]

Perhaps the 'removable storage' refers to the battery pack. It doesn't say what it stores....

[Namir]

That's no typo!!! He butchered the specs of the HP-45 mixing it with other HP calculator models!!!

Namir