Since completing my GB A1000 build and playing around in Workbench with my Amiga Tank Mouse, I remembered how awful the old ball mice were to use.  They really need a mouse pad (who has one of those now?) and they’re horribly inaccurate.  What I really wanted was an optical mouse.  However, I wanted to keep the Amiga looking standard, which meant keeping the Tank Mouse.  What I really needed was the two combined..

So, off to Google to do some research.  I found a project on Aminet for a PIC-based PS/2 mouse controller.  It was designed to take a regular PS/2 mouse and convert it to serial protocol to plug straight into the Amiga.  Taking a look at the project details, in it’s most basic form using a PIC16F628 there were almost no external components other than a decoupling capacitor.  I figured there was a good chance of this fitting inside the Tank Mouse case, thereby keeping everything else looking original.

So here is the original Tank Mouse with its internals:

Tank Mouse original

and here’s the donor PS/2 mouse I chose, because the microswitches for the mouse buttons lined up with the Tank Mouse buttons (but more on that later)

PS2 Mouse original

I needed to hack the internals of the Tank Mouse about a little bit to get the PS/2 board to fit

Tank Mouse hacked

and trial-fitted the PS/2 board to make sure the optical lens and mouse buttons would line up ok.

Tank Mouse ps2 controller trial fit

Looks to line up ok

Tank Mouse underneath trial fit

I programmed and socketed the PIC and fitted it to some Veroboard along with the wiring from the PS/2 controller and the Amiga serial lead.  (Hot Glue may have been premature..)

Tank Mouse internals 1

At this point I though I’d cracked it.. however, the mouse hardly tracked at all.  It seemed that the optical lens was mounted too high in the Tank Mouse case for it to “see” the surface underneath it cleanly.  A redesign was needed.  I had to chop the plastic lens piece right down to embed it into the Amiga mouse as close to the base as possible.

Tank Mouse hacked optical lens

This seemed to work well.  However, now I’d lowered the height of the microswitches too, so the mouse buttons weren’t actuating properly.  My solution was to steal the button assembly from the original Tank Mouse and connect this into the PS/2 mouse controller instead of using its onboard microswitches.

Tank Mouse buttons retrofit

Another quick test (I’m glad I kept the connectors on the wiring harnesses..) and all was looking good.  Time to fix the new board into place (again!) using a hot glue gun.

Tank Mouse internals fitted

And finally a completed Optical Tank Mouse using the original connector cable and right-angled Amiga 1000 DB9 connector.

Tank Mouse alive

It tracks really well, I’m really pleased with it.  I’m considering adding some weight inside the mouse as it feels quite light compared to the original Tank Mouse but I’ll see how I get on with it.

Thanks to Denis Sotchenko for his PS/2 mouse controller PIC firmware which I used in this project.

As part of refurbishing some Amiga 1000s I’d picked up, I wanted to clean up the cases which had yellowed over the years.  I’d tried retr0bright on the cases and whilst this worked in a few instances, in others I either got a bleached effect or I just couldn’t get all of the staining off.  Plus some parts of the cases were scratched, which retr0brite doesn’t help with anyway.

I’d been looking for something to respray the plastic with.  Conventional plastic spray paint seemed to be too messy and too thick – you needed special primer and then a plastic top coat.  Cases I’d seen sprayed had lost their texture and looked obviously resprayed.  I found some Vinyl spray paint which purported to do exactly what I wanted – change the colour of plastics without needing a primer and because the coats were very thin it didn’t affect the texture.  However, when I tried some of these paints I just didn’t get a particularly good result – I found even with very thin coats that the paint never seemed to really dry properly and would just get wiped off with IPA or other cleaners.

I kept searching and eventually stumbled onto Kolorbond.  This was paint specifically designed for plastics – specifically uPVC window frames – but also including ABS which is what the Amiga cases were made of.  I contacted the manufacturer and asked if they would colour-match against a piece of the Amiga case (the memory slot cover).  They said they would, and supplied me with a 1L tin of Matt-finish Kolorbond, along with WindowPrep which is used to clean the plastic before spraying.

Kolorbond WindowPrep

I stripped the Amiga cases down then started to spray them, first with dust coat of Kolorbond and then two “proper” coats which was enough to cover all the discolouration and the light sanding marks from where I’d cleaned up the scratches with wet & dry.  These are the pictures I took along the way.

Keyboard before:

A1000 respray keyboard base before A1000 respray keyboard top before

RAM Cover and Front Panel before (notice the original colour behind the RAM cover)

A1000 respray RAM cover before A1000 respray front panel before

Top cover and rear panel before (again, notice the colour staining – very bad on the rear panel)

A1000 respray top cover rear panel before A1000 respray rear panel before

One coat applied, getting better

A1000 respray RAM cover during A1000 respray front panel during

and the completed parts

A1000 respray keyboard side after A1000 respray keyboard top after

A1000 respray front after A1000 respray rear after

A1000 respray one case and keyboard after

I have to admin to being a little apprehensive about spraying these A1000 cases and possibly ruining them, but actually I’m really pleased with the results.  The only problem I had is that there was some “Commodore” text on the front panel which I had to spray over, but I think I prefer the look without this anyway. The colour match is almost perfect and the original texture of the plastic has been kept.  The paint doesn’t chip or peel off and also doesn’t wipe away with IPA.  They just look like new again.

Now on to building them back up into working machines again.