Wang 300 Calc

Tony Duell ard at p850ug1.demon.co.uk
Sat Sep 15 17:00:30 CDT 2007


[Mini-DIN plugs]
> Why, other than excessive stinginess did they switch to that, instead of
> the REAL 5 pin DIN that even I can solder?

Those mini-DINs are the worst (common) connectors to solder, but the 6 
pin ones are easier than the 9 pin. The Acorn Archimedes uses the latter 
for its mouse interface (it's a quatrature mouse with 3 buttons, the 9 
pins being +5V, ground, the 4 quatradure signals and the 3 button 
signals). 

Anyway the first Arc I obtained came without a mouse. Obtaining a 
3-button quadrature mouse was easy in those days (about 10 years ago), 
they were commonly sold as add-ons for the ST and Amiga. And getting a 9 
pin mini-DIN plug wasn't hard either.

But wiring it was,. Worse than that, as we all know, if you get the 2 
quadrature signals for a given axis the wrong way round, the cursor moves 
the wrong way relative to the mouse motion. So while I could connect up 
the power lines and the buttons with some certainty, I had to 'edit' the 
quadrature signals to get things going the right way. And that was 
downright painful

Acutally, I can see very little that's good about the mini-DIN connecotr. 
It's painful to wire, it doesn't have a good contact area, it's difficult 
to insuer (particularly 'blind', it's not that robust. I can see no 
reason qhy they should be used at all.

-tpny



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