"Han" wrote in message
...
"Martin H. Eastburn" wrote in
news:ZjW6l.88147
:

Talking about abacus ? I bet the third from the bottom on this page :
http://www.vintagecalculators.com/ht...lculators.html

Kingson Four-Rule

Martin

My Dad had one like that, but it got lost

I had one like that when I was a kid. I think it was the Exactus model shown
on the web site... the instruction manual looks familiar to me! I still have
a circular slide rule with the case and instructions... I got the slide rule
just as the TI pocket calculators were starting to drop from the $400-500
range to about $100 in the early to mid-70s. I figured the slide rule would
be a neat relic. Wish I'd realized that about the Additor type calculator.
;~)

http://www.vintagecalculators.com/html/exactus.html

I can recall how carefully you had to stick the stylus in the little notches
and move them... To get accurate results you really had to pay attention and
have a feel for the tool, much like using my hand tools vs. running things
over my jointer or through my planer. ;~)

John