The First Mouse: a Replica

This project recreates an important historical artefact from the 1960s: the first ever computer mouse. On December 9, 1968, Douglas Engelbart gave the Mother Of All Demos in San Francisco. It combined all of the following in a single system for the first time:

1. a computer mouse
2. a keyboard
3. a joystick
4. a 5-button chord keyboard
5. a graphical user interface
6. resizable windows
7. a WYSIWYG text editor
8. copy and paste
9. drag and drop
10. file sharing
11. collaborative remote text editing
12. video conferencing
13. audio codec
14. hypertext
15. graphics
16. dynamic file linking
17. revision control

The first prototype of the mouse consisted of a carved wooden block with two metal wheels and a single button. Bill English (the chief engineer at SRI) built it in 1964. A patent was filed in 1967. The patent suggests using a quadrature encoder or a Gray code with the wheels.

(Photos of the original mouse are from Wikipedia and the Doug Engelbart Institute.)

If you want to recreate the mouse yourself, you'll need

1. aluminium sheet
2. wood
3. a small optical mouse
4. two pushbuttons
5. brass tube
6. small self-tapping screws
7. M3 screws and nuts
8. M4 screws and nuts
9. wood screws
10. 4-core cable
11. a soldering iron
12. the usual hand-tools

The more "workshop" tools you have the easier it will be but simple hand-tools should suffice.

The original mouse used encoders attached to two wheels. I thought about doing it that way; in fact I've done it before.

But it requires a ball-mouse with a USB connection and they're very hard to find. It takes quite some effort to make that sort of mechanics and I didn't have the enthusiasm so I decided to use the electronics from an optical mouse. It will also be more reliable that way. You'll need quite a small mouse: search eBay or your favourite supplier for "retractable mouse" or "small mouse". It should cost around £5. Douglas Engelbart's original mouse had a square hole in the bottom which looks exactly like the hole in an optical mouse. I wonder why.

The chassis can be made from folded aluminium sheet. Ideally you should use 1mm sheet but I only had 0.5mm which worked just fine. The wheels should be from 4mm aluminium sheet but I had just enough 2mm sheet to make them.

A one-button mouse would be acceptable but I decided I would rather have a two-button mouse.

In the two-button mouse, the "y-wheel" is carried on a sliding/pivoting plate. If you press down above the y-wheel, it operates a pushbutton.

I first cut out paper templates and folded them to shape to try out the design. Then I used the templates to mark out the aluminium sheet.

The animation above shows how the parts fit together.

The wheel axles consist of an 18mmm long tube with 4mm internal diameter. Soldered round it is a 9mm long tube which acts as a collar. The brackets have a 9mm gap so the axle can rotate but the collar prevents it from sliding lengthways. An M4 nut-and-bolt secures the wheel to the axle. The bracket is held on with 2mm self-tapping screws.

The pivoting plate is held onto the main chassis with M3 nuts-and-bolts. Two nuts form a lock-nut so the plate is free to pivot. A "tactile" push button is glued between the chassis and the plate. The contacts of the push button are connected across the right mouse button.

The PCB and its sensor chip are hot-glued onto the chassis. The bottom of the lens assembly must be at the correct distance from your desktop. The gap depends on the chip in your original mouse - with my mouse it was 2.4mm.

The remaining corner of the chassis is kept at the correct height by the end-stopper from a ball-point pen. It's glued into a hole in the chassis.

For the wooden block, I chose cheap pine. Better quality fine-grained wood would be easier to work with but I wanted to match the original. You should drill lots of holes in the block then use a chisel to connect them up. If you have access to a milling machine, that would be a lot easier. The chassis is held in the block with small woodscrews.

You can find a suitable push button by searching eBay or your favourite supplier for "7mm push button switch". The push button is connected across the left mouse button.

The cable can be found by searching for "4 core shielded cable". Peel off the outer insulation and the result looks very similar to the original. I cut the cable to 1m long and spliced the far end to a normal USB cable. (Make a careful note of how the USB is wired up on your mouse. In the mouse I have, the D+ and D- legends on the PCB seem to be reversed!)

You might prefer to have the mouse wheels operate an encoder. You can see how I have done that in my other Instructable. You'll need to find a USB ball-mouse or you can start from scratch and use a processor that can act as a HID - I believe the ATmega32u4, the Teensy and the ATtiny85 can do so.

A large chunk of wood had broken off the original mouse. You could do the same.

You can add other of Doug Englebart's input devices such as a joystick, a grafacon, a knee operated pointer, a chord-keyboard and a light pen. A cheap "USB Encoder" used by retro-arcade builders will do most of the electronics work for you.