[comp.sys.apple] //e hardware modification request

jetzer@studsys.mu.edu (jetzer) (03/07/89)

I would like to modify an Apple //e for use with a handicapped child.  She
is able to type letters on the keyboard, but is too "slow," and holds the
keys down long enough for the auto-repeat to kick in, and many letters then
are registered.  As you might expect, the learning games do not like this.

I attempted to make a modification.  Page 164 of the Reference Manual (For
//e Only), says, in reference to the keyboard "The scanning rate is set by
the external resistor-capacitor network made up of C70 and R32."  I increased
the value of the resistor, but in doing so not all keypresses registered, and
the repeat rate was not reduced.

What I need, then, is a method of greatly increasing the amount of time before
the auto-repeat kicks in (about 10 seconds would be sufficient), or totally
eliminating the repeat.  It would better if a modification were easily
reversed (i.e., if a different capacitor were needed, being able to run it
through a double-throw switch so that either the normal or regular repeat
rate were selectable).  I am comfortable with soldering, removing/adding
components, etc., on the motherboard, so this is no problem.

I seem to recall that it is possible to change the repeat rate on a ][+ by
changing the value of a capacitor.  Is there a similar modification for
the //e?

(I tried posting this some time back, but got no responses.  I think we were
having problems posting news at that time.  Sorry if anyone has seen this 
before.)

-- 
Mike Jetzer
"Hack first, ask questions later."