On Mon, 26 Aug 2013, Mark Tapley wrote:
At 12:00 -0500 8/24/13, <cctalk-request at
classiccmp.org> wrote:
One crude wood abacus
8 column 5/2. BUT, the center bar is BADLY placed. It needs to be moved,
or remove one bead per column or you can't use it.
Has "Intel Inside" stickers
Nomination for "post of the year". Good thing I didn't already have
my morning coffee, it'd have been in the keyboard for sure.
I always figgered that "one of these days", I'd get around to fixing that
abacus, even though it is pretty crude (the wood isn't even sanded!)
I'm comfortable with a 4/1 - you count 4, and on the next count, you zero
the ones, and increment the 5s. It therefore counts to 9. When you
increment the count again, you zero the ones and the 5sm and
increment the ones of the next column.
But, some beginners have difficulty with the idea of clearing one field
while incrementing the next, for which 5/2 is handy - you count 5, and
then you "trade" the 5 ones for a 5. When you have two 5s, you
"trade"
them for an increment of the 1s of the next column.
But, this one has the crossbar placed such that there is insufficient
movement in the 1s field - there SHOULD be room to move a bead at least
the dimension of the bead.
Yes, a really experienced user only needs a millimeter or two of movement
for each bead. Such a user doesn't need one this crude.
Moving the crossbar (and sanding the wood) could make this a nice
beginner's abacus. OR, just remove one bead from each column, making it a
4/2, then there would be enough range of motion.
Oh, the stickers?
Well, when there was a roll of Intel stickers kicking around, they showed
up on space heaters, a clear vacuum bell jar, the toilet, Apples (both
computers and fruit), etc.
The "In case of emergency, break glass" box with the slide rule and abacus
got claimed, even though the actual "In case of emergency, break glass"
sign was missing.
But, so far, nobody has requested this one.
--
Grumpy Ol' Fred cisin at
xenosoft.com