Tablet computers: An overview

As businesses wrestle with an influx of 'bring your own' mobile devices, we examine where tablets came from, what they have evolved into, how they can enhance business productivity, and how they're likely to develop.
Written by Charles McLellan, Senior Editor

Tablets have been around for decades, but have recently, along with smartphones, moved centre-stage as the 'post-PC' era, which is characterised by the widespread use of wireless-connected mobile devices, gathers pace. The post-PC generation has a 'work anywhere, anytime' expectation, which C-level executives (who are often early adopters of mobile technology) are generally happy to encourage. These are some of the forces driving the consumerisation of IT, which can provide IT departments with security, management and compliance headaches when employees 'bring their own' devices, applications and cloud-storage services.

In this article, we examine where tablets came from, what they have evolved into, how they can enhance business productivity, and how they're likely to develop.

The history of tablets

Captain Kirk with a PADD (and Dr Leonard 'Bones' McCoy).

Apple's first-generation iPad may have inspired the recent tsunami of tablets, but the form factor goes back a lot further than 2010 (although, interestingly enough, there is a very early Apple connection).

The idea of portable touchscreen devices connected to information repositories, often with advanced capabilities such as wireless connectivity, speech recognition and artificial intelligence, is prevalent in the science fiction of the 1960s and early 70s (a pre-PC era when computers were anything but portable). Notable examples are the PADD (Personal Access Display Device) in Star Trek, the Newspad in 2001: A Space Odyssey, and the Hitchhiker's Guide to the Galaxy in the BBC radio series of the same name (for more tablet history, see our accompanying timeline infographic).

The Apple connection comes via visionary computer scientist Alan Kay, who was an Apple Fellow, mostly at the company's Advanced Technology Group, from 1984 until 1997. Prior to that, Kay worked at the renowned Xerox PARC, where in 1972 he produced a seminal paper entitled 'A Personal Computer for Children of All Ages'. This was a blueprint for an education-oriented portable computer, summarised thus:

Alan Kay and a prototype Dynabook.
Image: Wikipedia

The size should be no larger than a notebook; weight less than 4lbs; the visual display should be able to present at least 4000 printing quality characters with contrast ratios approaching that of a book; dynamic graphics of reasonable quality should be possible; there should be removable local file storage of at least one million characters (about 500 ordinary book pages) traded off against several hours of audio files...A combination of this "carry anywhere" device and a global information utility such as the ARPA network or two-way cable TV, will bring the libraries and schools (not to mention stores and billboards) of the world to the home. One can imagine one of the first programs an owner will write is a filter to eliminate advertising!

Not bad for 1972 (note: 'the ARPA network' is the nascent internet) — especially as Kay goes on to specify voice input, a low-power flat-panel LCD display with a resolution of 1,024 by 1,024 pixels, a touchscreen model with an on-screen keyboard and a target price of $500.

GridPad: the first commercially available tablet.
Image: DigiBarn Computer Museum

Apple's own tablet computing project began in 1987, inspired by the conceptual Knowledge Navigator, its first product being the (roughly) A5-sized Newton MessagePad, released in 1993. This wasn't the first commercially available pen-based tablet, though: that accolade goes to GriD Systems' 1989 GridPad, which ran MS-DOS. The first purpose-built pen-based operating system was GO Corporation's 1991 PenPoint OS — a development that spurred Microsoft to enter the fray with Windows for Pen Computing 1.0 (an extension of Windows 3.1) in 1992.

Several other landmark devices — notably the first IBM ThinkPad, the 700T — appeared before the next phase of tablet computing, which kicked off when Bill Gates took to the stage of the MGM Grand Garden Arena in Las Vegas to deliver the keynote at Comdex/Fall on 13 November 2000 (I remember it well...I was there). During the speech, Gates (and Microsoft software architect Bert Keeley) demonstrated a prototype Tablet PC with a 600MHz CPU, 128MB of RAM, a 10GB hard disk and a pair of USB ports. This slate-style device ran a beta version of Windows XP (codenamed Whistler) with pen computing extensions, and showcased 'rich digital ink' that captured on-screen handwriting and drawing for instant or deferred manipulation.

Microsoft's prototype Tablet PC, unveiled at Comdex/Fall in November 2000.
Image: Microsoft

Plenty of Windows tablets — both slates and convertible clamshells — appeared between 2000 and the iPad's launch in April 2010, but despite winning some converts these devices didn't take the mainstream computing world by storm. However, tablets — often ruggedised ones — did become established in vertical markets such as healthcare, construction, field service and retail.

Despite Microsoft's best efforts, the 'after iPad' tablet story is one of market domination by Apple, with Android-based tablets —mostly made by Samsung — emerging as the main challengers. A number of alternative platforms and devices, including BlackBerry's QNX-based PlayBook and HP's short-lived webOS-based TouchPad, have fallen by the wayside over the years. Microsoft's latest move was to get into the tablet hardware business itself with the Surface RT and Surface Pro devices, which debuted in 2012.

The tablet market today

Here's a snapshot of the tablet market at the end of 2013, showing Apple as the leading vendor, with Samsung in second place, and Android as the leading platform, ahead of iOS. In both graphs, the 2012-2013 trend is downwards for Apple/iOS and upwards for Samsung/Android:

(Source: IDC)
(Source: IDC)

By 2017, IDC forecasts that Microsoft's Windows will have grabbed around 10 percent of the tablet OS market share, with Android leading at 59 percent and iOS in second place at 31 percent.

A taxonomy of tablets

Tablets come in a number of shapes and sizes, and since the form factor largely determines the use case, it's useful to set out the various subcategories. There are no 'canonical' definitions here, but hopefully this list isn't too far off the mark:

The History of Tablet Computers: A Timeline

Phablet  With 6-7in. screens, phablets sit mid-way between smartphones and small tablets, offering a better viewing, reading and document editing (or even creation) experience. Most leading smartphone vendors, with the notable exception of Apple, now offer a phablet (Samsung Galaxy Note 3, Sony Xperia Z Ultra, Nokia Lumia 1520, HTC One Max, Acer Liquid S2).
Small tablet  For many people, 7-8in. tablets provide an ideal combination of portability, (moderate) computing power and screen readability. Leading examples are Google's Nexus 7, the Apple iPad Mini and Samsung's Galaxy Tab 3 7.0.

Medium-sized tablet  This is the mainstream tablet subcategory, typified by the full-size iPad, featuring a 9-10in. screen. Portable, but not pocketable like a 7-8in. tablet, these more powerful devices will often have optional add-on keyboards or docks to support heavier-duty content creation workloads.
Large tablet  Still relatively rare, tablets with 10in. screens or larger, such as Samsung's Galaxy NotePRO 12.2, offer the best viewing experience, and can accommodate several apps on-screen simultaneously, making for better productivity. The trade-off, of course, is decreased portability. Panasonic's 20-inch Toughpad 4K Tablet, the biggest and most powerful tablet currently available, is something of an outlier.
Hybrid/convertible  These are keyboard-equipped touchscreen devices, usually with 10in. screens or larger, that have some sliding, twisting or keyboard-removal mechanism that allows them to switch between laptop and tablet modes. There are many examples, including Microsoft's Surface Pro 2 (with keyboard cover), the Asus Transformer Book T100 and Lenovo's ThinkPad Yoga.

Tablets of various kinds fill the gap between 'mobile communication and content consumption' devices (smartphones and phablets) and 'mainstream mobile productivity' devices (hybrid/convertible tablets, ultrabooks and 13-15in. notebooks).
Image: Charles McLellan/ZDNet

If we look at tablets in context with other kinds of computers (see diagram above), we can see that they fill the gap between 'mainstream mobile productivity' devices (hybrid tablets, ultrabooks and 13-15in. notebooks) and those that major on 'mobile communication and content consumption' (smartphones and phablets). The more content editing and creating you want to do, the more likely you are to require a tablet with a larger screen and a keyboard (either as an add-on or as part of a hybrid device).

If your content-creation workloads demand the fastest CPUs, heavy-duty discrete graphics and, in particular, large amounts of screen real estate, then today's tablets (the aforementioned Toughpad 4K Tablet excepted) are unlikely to be up to the job. Sometimes you'll be able to hook up to a big monitor, but often you'll need to consider a larger and more powerful notebook, desktop PC or workstation.

However, given that today's smartphones pack the computing muscle once associated with 'powerful' desktop PCs, there's no reason why this trend, along with increasingly sophisticated cloud-based services, shouldn't continue. This would mean that you'd carry one (powerful, richly connected) mobile device, and simply access the most appropriate display for the situation you're in.

Ubuntu for Android, which runs Android in smartphone mode and Ubuntu Linux when docked on the desktop, is a stepping stone to a fully converged version of Ubuntu that will support form factors from phone to large-screen desktop.
Image: Ubuntu

These ideas underpin Canonical's plans for the Ubuntu Linux distribution, which is eventually planned to have a flexible user interface that will accommodate smartphone, tablet, PC and TV screens. If you carry a 'superphone' such as Canonical's (almost) crowd-funded Edge device, you could bring it into the office, dock it with a monitor, keyboard and mouse, and carry on working with whatever apps were open, only in desktop mode.

Tablets as business tools

Tablets have had a few years to work their way into businesses, and a number of surveys have examined how they are being put to use, and also how they're being managed.

Enterprise content management/collaboration company Alfresco surveyed 308 professionals in mostly small-to-medium-sized businesses in 2012 and found that 76 percent used tablets for business purposes. The breakdown of usage is not unexpected, with communication and content consumption prominent:

Source: Alfresco Study: IT Leading Tablet Adoption in the Enterprise (Alfresco, 2013)

A high proportion of Alfresco's respondents (56.4%) worked in IT, with engineering and R&D in second place (10.5%). This suggests that tech-savvy early adopters (64.1% of respondents described themselves as such) were driving tablet adoption in the businesses surveyed. However, despite the high penetration of tablets in IT departments, only 17.3 percent of respondents said that their company had implemented a formal tablet use policy, and just 25.3 percent required the installation of security software. Bear in mind that the respondents were mostly from SMEs; it's unlikely that the 13.1 percent from enterprises with 10,000 or more employees were working under such an informal regime.

Alfresco also asked respondents about the situations when they used tablets, smartphones and PCs. Echoing our taxonomy discussion above, the results show very clearly how tablets fill the gap between more mobile smartphones and more powerful but deskbound PCs:

Source: Alfresco Study: IT Leading Tablet Adoption in the Enterprise (Alfresco, 2013)

Another 2012 survey, from Microsoft-centred consulting services provider Avanade, also looked at tablet usage in business. A key point to emerge from this study, which canvassed 599 C-level executives in 2012, was that a third of respondents said they used tablets for 'advanced' business functions such as CRM, project management, content creation and data analysis. Another indicator of the impact of the consumerisation of IT is that 71 percent of respondents said their company had altered at least one business process — such as IT management, sales and marketing, HR or customer services — to accommodate the increased use of smartphones and tablets, while 20 percent said they had changed four or more processes.


Examine any article about tablets on this website and you'll usually find a lively debate in the comments section about the pros and cons of the form factor and/or the operating system. That's only natural when a relatively new style of computing is finding its feet in business — or, more accurately, the intersection between business and home.

What's clear is that tablet computing has a lengthy heritage, has now become a productive component of business IT, and will continue to evolve as mobile devices become more powerful, screen and battery technology improves, and software platforms become more flexible.

A generation ago, visionaries imagined having natural-feeling conversations with properly intelligent agents on super-connected 'carry anywhere' computers; we're not there just yet, but we're a lot closer.

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