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Motivation

The keyboard, mouse and graphical terminal are the most common interfaces to modern PCs. Indeed, these devices are easy to learn to use and are effective ways of interacting with computers. However, the problem with using both a standard keyboard and mouse is that one hand needs to move between both devices.

Furthermore, consider a right-handed person using a standard QWERTY keyboard and mouse: the mouse is to the right of the numeric keypad - about 30 centimetres from the home position of the right hand. The inconvenience of this arrangement is sufficient to make people prefer to navigate using the arrow keys on the keyboard rather than the mouse.

Of course, there is a lot to be said for giving users the choice in their user interface, but when people prefer to press the cursor keys 20-30 times in preference to moving a hand to the mouse (which could be done so much easier and faster) there is something wrong.

From personal experience, the problem is the inconvenience of actually finding the mouse (by looking away from the screen), moving my hand the large distance to the mouse, and then moving the hand back to the typing position.

Over the years, I have used several different experimental keyboards and mouse arrangements to try to overcome the problem

Moving the mouse closer

An obvious solution is to move the mouse closer to the keyboard, and I have used two different ways to do this.

I note that I rarely use and of the keys to the right of the main section: the numeric keypad, the page up/down, home, delete area, or indeed the cursor keys are hardly ever required. So my first alternative keyboard design was to take a standard QWERTY keyboard and to construct a mouse platform over the right hand side of the keyboard. It was simply a horizontal cardboard platform with a mouse mat glued on top.

This was actually extremely effective. I used it for several years on all the computers I used. The platform is easily removed and portable so I carried it around when I was working on the shared general purpose computers in the software labs. I still use the same platform on my home PC.

The lack of cursor keys was not a problem. After an hour or two of use, I soon realised that now the mouse is much more accessible, the cursor keys are not necessary. A few times, applications demanded the use of cursor keys, so I software mapped them to F5-F8. They are still rarely used. I never need to use any of the other keys covered by the mouse platform.

One slight problem is the height of the mouse platform (about 4 cm from the desk). For general use (text editing etc), this is not a problem because the hand is regularly moving between the keyboard and mouse. However, for applications that demand heavy mouse use (graphical tools etc) my hand tended to tire after about 30 minutes of use.

The height problem was reduced in a variation by Mike Bennett who removed the key tops from the right hand side of the keyboard and rested the mouse-mat directly on top of the top of the keyboard. This provides non-horizontal surface for the mouse, but is still extremely effective. Mike uses this arrangement for general use at work.

Small Keyboards

If you feel like being more destructive, there is always the option of taking a standard keyboard and cutting it in two. I have done this and found it to be very effective. The mouse can be placed at desk height, right next to the home position of the right hand.

There are several small keyboards available from suppliers on the internet, but they are naturally more expensive than a larger standard QWERTY keyboard.

One handed keyboard

It occurred to me that it would be nice to be able to keep one hand on the mouse at all times, leaving only one for the keyboard. It does not take long to realise that typing one-handed on a QWERTY keyboard is extremely difficult ("I am invincible!" --Remember Borris, Goldeneye?). One-handed keyboards are not exactly new, but there are few available in mass-production. So, I set about designing my own.

Left Hand Dvorak: Left Hand Dvorak layout on a standard keyboard

The first attempt was to take a standard QWERTY keyboard and to re-arrange the keys so that they were in a suitable arrangement for one-handed typing. I am right handed and am used to controlling the mouse with my right hand, so I needed a left hand keyboard. I started with the Dvorak left hand layout on (keymaps come with Linux distributions and probably Windows too). I used this for a few months, adjusting and moving keys where necessary. I was quite surprised how easy it was to learn to use. I did no typing tutor-style exercises, yet within a few months I could comfortably do 15-20 words per minute (hardly fast, but definitely usable).

Here is a similar keyboard layout that a colleague Mike Bennett used daily for some time.

The problem with this arrangement was that I could not reach all the keys without a stretch. I have small hands and when reaching for key at the extremities of the keyboard, I had to look at the keyboard to get any accuracy. I did not feel comfortable using the keyboard.

However, I did feel that there was merit in the design and decided to construct a keyboard where the layout was more suited to my hand. So, taking a large empty piece of strip-board, I put my left hand in the middle and soldered a key where my fingers landed. Then, working outwards from the four home keys I constructed a one handed keyboard to fit my hand. The advantage of this is that I the keys are no longer constrained to the straight lines that a QWERTY keyboard has.

One-Handed Keyboard: Side view of one-handed keyboad showing scale

The layout was basically the same as the Dvorak keyboard that I had been using previously, with a few alterations, and of course, the keys can fit to the natural curved shape that my fingers can reach.

At first, I placed most of the keys that are in the main section of a standard keyboard into my keyboard, but this produced a very large keyboard and made the symbol keys hard to reach. So, I removed many of the symbol keys and software mapped them onto the letter keys with a Meta key.

This is comfortable to use and is the keyboard that use daily at work. I can do 20-30 words per minute typing, which is sufficient for me. The main advantage is that I can keep one hand on the mouse at all times. This makes editing extremely easy, since the mouse (right hand) is used exclusively to navigate, additions being made by my left hand. The keyboard is small and takes less desk area than a standard keyboard.

The home position is to put my first finger on the E and little finger on the D. The second finger only uses the keys coloured red, the third finger only uses the keys coloured blue. The thumb is used for the delete, enter (insert key), space (the big minus), control and Alt (meta key for symbols), and the brackets.

One Handed Keyboard Closeup: View from above, showing the key layout

There are several spare keys (unused at the moment) which are left over from the initial version where there were too many keys. I left a few spares in "for future expansion", but as I have not found a use yet, they won't last long.