Re: Trying to fix an Apple II...

[Jeronimo Pellegrini <jeronimo@dcc.unicamp.br>]

Thanks for replying!

>      The Speed adjustment, assuming there is one, would most likely
> be to change resistance in some circuit. So; you are looking for a
> mini potentiometer with a slotted screw shaft or slotted opening. 

I think it was a potentiometer taht I adjusted (there's no other
visible adjustable thing inside the drive). I'd like to check
it. In which range it's resistence should be? I can measure
that... Maybe I just need to replace it.

>      Be sure to try cleaning the drive head. (Squirt cleaner on a
> Radio Shack Head Cleaner disk and insert it, open side down, into
> the drive. Leave drive door open, boot the drive, and close the door
> gently. Let spin for about 20 seconds or so.)

Are there reasonable alternatives if I can't find a head cleaner disk?
(I live in Brazil, and I don't know if these are still sold here...)
 
>      The 555 is a "timer IC" which can be used for lots of things
> (like an oscillator, a variable pulse width one-shot, ...).  In
> the Apple II+, a 555 is used to fire off the Reset pulse when
> the computer is turned On. I did not find a 555 in a check of
> the IIe schematic. Maybe what you have is a II+ (or, maybe,
> early IIe's had a 555).  If, when you start up the computer,
> you see "APPLE II" (all upper case letters), then, you have a II+. 

Well, it's a clone, and its ROM is not Apple's. So it says
"COMPUTER" when it boots (how insightful...). I can use upper and
lower case letters (there's a key to lock it in lower case; it's below
the right-side shift), and there's only one cable connected to the
motherboard (it goes into an IC socket). I also saw nothing like that
"VIDEX" thing in the keyboard. And the keyboard has programmable macro
functions which use the numeric keyboard.

Is there another way to tell if it's a II+ or an unenhanced //e?

Btw, it has 2 "NE555" ICs. I tried removing one of them. It didn't
boot. then, tried removing the other. It booted normally, but entered 
sometimes (spontaneously) in GR mode (!)...

> Rubywand

Thanks a lot!

Jeronimo Pellegrini