IanG on Tap

I've been using the same mouse for 3 laptops now. It was one of the earlier Microsoft USB mice with an scrolly wheel. It's all black, and it's the classic old-style Microsoft mouse shape, with a rubber ball rather than optics, and technically, it has been on loan from a friend all this time. (You know who you are. Would you like it back now?)

I did actually order a new mouse with my current laptop. The old one is working fine, I just thought it was bound to give up the ghost sooner or later, since I take it with me on all my fairly frequent travels. And a new mouse did indeed turn up. Dell even used it as an excuse for why the laptop shipped late. (Actually, it was one of several excuses. It was only when I cancelled my order that the laptop eventually turned up, and not before I'd placed an order with a different manufacturer!) However, the mouse had a PS/2 connector. My laptop (supplied by Dell, the same people supplying the mouse, just to be clear) doesn't have a PS/2 socket. So I carried on using the same old mouse.

I've been meaning to upgrade the mouse for a while. My desktop has an optical mouse, and it's a whole lot better, so I kept meaning to get around to buying a new one for my laptop. But whenever I buy new stuff I always want to get something that is somehow an improvement on what I had before... And since my laptop has built-in Bluetooth, the obvious improvement on the Intellimouse Explorer I have on my desktop would be the Bluetooth version of the same. Given the state of my desk, not having a cable coming out of the front of the mouse would actually make an appreciable improvement on manoeuvrability.

So I got myself one of these:

http://www.microsoft.com/hardware/mouseandkeyboard/productdetails.aspx?pid=001

(I'm not sure how stable that URL will be. I find that pid=001 indicative of a habit of redesigning things on a regular basis... It's a Microsoft Intellimouse Explorer for Bluetooth, if that link expires by the time you read this.)

Physically, it's great - it's more or less like any other Intellimouse Explorer, except it's a dark metallic blue. (And because it's battery powered, it doesn't have the extra LED featured on the back of normal Intellimice whose only purpose is to make the light shine out of its arse.) In operation it's...OK.

I was interested to see how well it was going to work, because there are two obvious challenges with building a Bluetooth mouse. One is power management - it has to run on batteries as a power cable would pretty much defeat the purpose of a wireless mouse. There's a tension between making sure the mouse doesn't appear to fall asleep all the time, but also not chewing through batteries. The other challenge is the real-time element - is the latency on Bluetooth good enough for an input device?

The power management thing is occasionally intrusive but bearable. If you've not used the mouse for a while, there's a bit of a hiatus before the mouse responds - somewhere between 0.25s and 0.5s. I can live with that as there's already a larger hiatus involved in taking my hand off the keyboard. And significantly, although there's a delay, it doesn't seem to lose any input - if you move the mouse when it's in its low power state, it does register that movement when it wakes up. (I was worried that it might only track movement once it is fully powered up, but it appears to buffer stuff. So I guess the hiatus is not how long it takes to power up, but how long it takes to re-establish the connection with the computer.)

As for the effect this has on battery life, I really couldn't say. Three days of solid use so far, and the battery indicator still seems to think the batteries are full. Then again, my current phone also says that it's full of charge right up until about 2 hours before it runs out of charge completely...

Latency on the other hand is mildly disappointing. There is a lag between moving the mouse and seeing the mouse pointer move. It's like the mouse cursor is struggling to keep up with where I'm asking it to go. It's a pretty tiny lag, to be fair. I just happen to be very sensitive to these things - I find non-linear control responses much more disturbing than most. I find mouse acceleration almost unusable for example. But I would guess that if you are able to put up with mouse acceleration (now ironically labelled "Enhance pointer precision" - actually it does more or less the opposite) then you probably won't notice the lag.

It's possible, I suppose, that it would be better if I used the Microsoft Bluetooth dongle that came with the mouse. But the whole point was to reduce the quantity of cabling by using my laptop's integrated Bluetooth, so I'm not going to be trying that.

And even though I'm ultra picky about these things (if it's picky to want the cursor movement to track mouse movement accurately; I've never understood why this is regarded as an unusual requirement) the lag hasn't caused me to go back to the old mouse yet. (Which is still plugged in, and within easy reach on the desk, so it's not like it would be a big effort to switch back.)

So in summary: the lack of cables great; it's too soon to judge the battery consumption; the physical design is great; the feel of connectedness with the cursor on screen could be better, but is acceptable even to someone as picky as me.