SGI: Hardware

I like to have original mouse, keyboards and monitors to my SGIs to get the correct retro 90ies feeling.
The ball mouse is no favorite though. I guess that most people even in their most nostalgic moments don't want to use it if they can avoid it.

So I built this.

It is an original Granite Indy mouse with the electronics from an MS explorer mouse inside!

It's a joy to use, and without the heavy ball inside the mouse is feather light gliding over the rubber mouse mat with unhindered ease.


Here is a guide how to do the conversion.
Start by getting an Explorer mouse, thats an old 5 button Microsoft mouse with a red light at the bottom.

Why this mouse ?, well it has a very small circuit board so it is easy to fit in the old SGI mouse plastics. It also works well and is PS/2 compatible.

I used the optical encoder from the MS explorer mouse but not the buttons as they did not line up well to the plastic push rods in the SGI mouse.
Instead I used the original buttons from the SGI mouse.
I then linked the SGI buttons with the MS explorer board using a few wires as shown in this diagram.


To start the conversion first open up the explorer mouse and remove the electronics.
There are three circuit boards, you want to keep the middle one that holds the optical encoder.


De solder the small board that holds the red led, it has no function other than to "pimp" the explorer mouse.
Also remove the front circuit board, It will be easier if you cut the wire that links the two boards and then clean out the remaining wire from the solder pads.

Once you have cleaned the solder pads put the explorer board aside together with the plastic lens from the bottom of the explorer mouse.
It is now time to turn your attention to the SGI mouse and to fire up the dremmel tool!
Remove the SGI mouse circuit board and with the dremmel tool cut across the board 2 cm under the buttons.

Discard the old SGI board and test fit whats left of the button boards in the SGI mouse again.

No comes the most critical moment in the build, glue the plastic lens from the explorer mouse under and up in the hole that used to hold the ball in the SGI mouse.
Make sure you get a flush fit of the plastic lens to the underside of the mouse, you need to cut or file two small indents to get the plastic lens flush and level to the underside of the mouse
If you get it wrong the lens will be out of focus and you mouse will not work.
Epoxy glue the the lens to the underside.
Let it cure and then flip the mouse over and glue it from the inside as well.
Drop in the button circuit board and test fit it, file or trim it until it sits well.

Now its time to wire it all toghter.
In this last picture you may notice the six solder pads near the left mouse button. In the top mid hole there is connection to all buttons so thats an excellent place to solder the 180ohms resistor that needs to go in series with the return wire from the button switches.

At the other end of the resistor solder a piece of wire.
Then solder wires to all three switches, every switch has three connectors, solder the wire to the mid connector.


No its time to connect it all.
The 180 resistor needs to go to ground, I used pad 8 on connector J2.
Left button switch wire goes to pad 2 on J3 connector, mid goes to pad 3 right goes to pad 4.
And last, complete the soldering by soldering the SGI mouse cable to the J2 connector.
Closeup of the button wires.


Closeup of the SGI mouse cable.


Now assemble everything

and test the function of the mouse by plugging it to an old PC or so in case it fries the computer. Once it runs fine on a PC you can test it on an SGI computer and run a confidence test in IRIX to check out the buttons and movements.

To get the mid button to work you first has to set the systune pcmouse 2 parameter in the kernel
Read this blog entry for more info http://www.nekochan.net/weblog/archives/000025.html

If you don't get good mouse movement, try to lift the optical board at the back end a few millimeters. I found that one of the de soldered micro switches from the MS explorer mouse had the correct height so I ended up placing it under the back end of the pcb and fixing it with heat glue.

Once everything checks out, fix all the boards and cables with heat glue from your trusty glue gun!

Put on the top, screw it down and you now have a unique optical granite mouse that will be as smooth as silk on an Indy mouse mat!

//deBug

excellent hack!!... now I'd put some weight into it to give it a solid feel.

pinball_0 wrote: excellent hack!!... now I'd put some weight into it to give it a solid feel.

Thanks.
When it comes to weight, I guess there is two schools
Some people like it to be heavy some dont.
I opened up an old optical Logitech mouse and found that they had placed a weight inside it so I guess their design department thought their customers liked them to be heavy.

Myself, I like it to be as light as possible.

Thats really awesome!

Those intellimouse opticals are actually really nice, shame to see one go like that. Maybe I should get another old mouseman and stick my right-click-is-stuck MX500's internals into it. Actually I have a 4-button mouseman coming my way...


deBug: I think they do like it heavy, I use some of the weights in my Logitech G5. I don't care if it's light as long as it feels solid, not like those razer pieces of crap.

Excellent. You could sell those.

noisetonepause wrote: Excellent. You could sell those.

Hehe, always nice to have a second carer to fall back to should my IT manager skills fall out of vogue
Although I think the world market would be somewhat limited as most people would probably just use the explorer mouse as it is.

excellent hack!!, i like the feel of that type of sgi mouse, especially the "click" is very precise and holds well in the hand. although when moving it on the desk is a bit "bumpy" ... the thing i miss the most on it is the scroll !

I prefer the heavier mice. when I replaced my wireless mx700, I got an mx518 which is the same shape and has the same buttons. finding it to be much too light (because there are no batteries) I had to put some leaded weights in it. I don't like the feeling of an empty plastic box that creaks when you squeeze it. I actually had a lot of trouble going to the optical mice when they came out, after using a logitech trackman vista my entire life. if logitech makes a mouse the same shape as the mx only machined out of aluminum, I'd pick it up in a heartbeat.

I don't see how you are getting a classic '90s feeling by stuffing modern parts inside, though. or keeping it 'authentic', if that is the goal. I suppose I just see cleaning out the ball as part of the system maintainence, like getting the dust out of the heat sinks. when the ball is clean the mouse works pretty good.

excellent hack, it looks original from the outside and probably works much better. pretty funky mousepad you got there too.

^^ Looks great, deBug. How about a wireless one next time ? That would be truly awesome

sybrfreq wrote: pretty funky mousepad you got there too.

That one's a classic. SGI used to give those away in the late 90s. IIRC, they came in the box with some new machines, and they gave them away at some of their training courses. Every now and then you'll see them on eBay.

Certainly a nice, well done job - but I've never really understood the huge objection to the roller balls. Sure, you gotta clean them every so often. I only used these until a month ago, when I got this nice MS optical piece of crap. The optics doesn't bother me, but the middle mouse button (under the wheel) only functions 20-30% of the time. I'm not sure if this is a design flaw (feels like it could be the driver) or if this is a problem just with this unit. Right now I manage by programming the two side buttons to be a middle mouse button, but it'll take a while to undo years of training (my main app makes extensive use of it).

FWIW, one of the earlier Logitech MouseMan designs used a very lightweight ball. I thought these functioned much better, with the lighter weight they didn't seem to pick up the dust and put them on the rollers - you could go years without cleaning. But I guess they thought people liked the feeling of heavier roller balls....

Great work on this! I'd give it a go myself if I had some extras lying around

I have to second that this is an excellent hardware hack. Congrats!
If there only were more of this here.

I´d build me one optical SGI mouse immediately from a spare granite one but...
...I´m a convert - into a spaceball (Cordless TrackMan FX, to be precise) addict already.
Once one has worked with a trackball mice are no longer an option.
Y´know: no more RSI pain because precision work gets done with the fingers instead of the arm.