I’ve been reading Alan Kay’s 1972 paper on the Dynabook
His visions of what the product would be capable of, in reality took about 40 years to materialise and coalesce into a comparable product. It could be argued that modern laptops and tablets are the direct descendants of his vision.
Some of the prerequisites would be:
- A commercially available 16-bit or 32-bit cpu - 8086 in 1976, ARM 1 1985
- Affordable IC memory ~ 1980
- A monochrome LCD capable of 512x512 pixels ~1990
- Battery with sufficient energy density (LiPo) ~2000
- Solid State Drives eg MMC or SD 1997, 1999
- Affordable network connection www 1994
So realistically such a product could not be constructed in volume until roughly 2000.
However, one early contender was the Atari ST-Pad from about 1991, just at the time Atari was moving away from personal computers.
The two products that best encompass the original Dynabook concepts are the One Laptop Per Child - announced 2005 and the Amazon Kindle, released in late 2007. The true tablet finally arrived in 2010 with the launch of the iPad.
It takes a true visionary of technology to predict the arrival of computing devices that would take 20, 40 or even 50 years to become technically and commercially viable.