Looking for AT&T 3B1/UNIXPC/PC7300 software

[Tony Duell]

> I had it all apart (it is difficult to take this thing apart !)
> 
> There was a small 'sliver' of plastic cracked away at the front in front
> of the keyboard... I glued that.  The larger crack in the back doesn't
> want to close well (even with a clamp), so I doubt superglue would
> work very well... so since it is not very apparant, I'll probably fill the

I haev never had much success with isocyano acryllic hydro copolymerising 
adhesives...

If you can find a solvent for the plastic (and for quite a few 
thermoplastics dichloromethane (methylene choride) -- sold by good model 
shops unde the name 'Plastic Weld' -- works well), you can weld the 
plastic by pushing the edges together and then running a brush dipped in 
the solvent along the cracks. To make the joint even stronger, cut a 
piece of cotton fabric to fit over the back of the damaged area, put it 
in place, and 'paint' it with the solvent. Then push the fibres into the 
softenend plastic.

If I have a plastic that I can't weld like this, or that needs to be as 
stong as possible, I cut a piece of metal or fibreglass (PCB material 
with the copper etched or sanded off) to fint over the breaks and then 
fix it in plasce with small nuts and bolts. It may not look neat, but 
it'll keep the case together.

> crack with epoxy to strengthen it and that should do.  The metal
> that was bent was straightened... but a metal tab where the back
> metal screws onto the side metal was a casualty... it broke off while
> trying to straighten it.... but not a big deal, as it is held on by 3

Can you make an angle pracket to replace the damaged part here?

> other screws....  assembled you'd never even know.
> 
> I must say this thing is really difficult to take apart and put
> together.... it has pretty good build quality though.  The toughest
> part is that the rear case binds on the floppy drive power
> connector....  if I had followed the 3B1 FAQ recommended
> disassembly procedure I probably would have broken the floppy
> drive PCB.  I took the monitor off the top, that allowed me to
> see what I was doing... there was just enough room to use long
> needle nose pliers to disconnect the floppy drive power connector.
> reassembly will be fun....

On at least one amchine I've worked on, one of the drives has the power 
connector desoldered from the PCB and replaced by a cable-mounted 
connector (think of the male end of a PC drive power extension lead) with 
wires soldered to the original holes in the PCB. This meant the power 
connector didn't get in the way of another bit of the machine. If you try 
to make this modification, make sure, and check again, that you've not 
swapped the +5V and +12V wires round!

-tony