Re: More info A curious small circuit baord from a "]["?

[Delfs <delfs@NOSPAMapple2.com>]

The chip 74xx153 is a demultiplexor that looks for a specific input signals and
then outputs a signal based on the inputs.
http://www.ee.scu.edu/classes/1999winter/elen021/labs/specs/ds74153.htm

It sounds like and old Apple II hardware device to use the Apple key like a shift
key to get Upper/lower case letters on the II/II+.  Heard of one, never actually
used on on my II+ though.  The mod also required a new character ROM or 80 column
board as the original II/II+ character ROM did not have lower case character set.

It shouldn't be in a IIe though.  Maybe it's something else.  For fun, try using
it as a shift key when you have your CAPS lock on and see what you get.

Thankx,
Ed

Bart wrote:

>  Today I found this inside a //e (well the lid says //e, the RAM is in the right
> place for a //e, but it
> >boots to "Apple ][" : It is a circuit board about 3.5 by 1 inch in size. It
> >has 1 ribbon wire going to a IC pin set (male, 16 pins), a female on 1 side,
> >male on other ribbon wire sockets for 28 pins and is marked "QUARK" on one
> >side and "ALF" on the other.  It has 1 IC  on the board that is the size of a
> >64k chip and is marked DM74S153N.
> Well I figured out WHERE this board goes, but I still have not a clue WHAT it
> is for: the male to female 16 pin connectors are suposed to fit on the ribbon
> wire for
> the keyboard, and the IC looking dongle on the other ribbon wire connects tot
> he game port.  I hooked it up so and it still boots ok, but as I said, what it
> is for?  Have not a clue.