Re: Apple 2C Question

[dempson@actrix.gen.nz (David Empson)]

frank malinowski <Xyakers@earthlink.net> wrote:

> This looks like the right newsgroup to get some help with the 2C which has
> gone disfunctional in my wife's classroom. When I try to boot up it does
> start and with the system disk It gets as far as the initial menu and then
> the screen goes crazy-into a mostly linear patters.

I'm not sure what this menu might be (it depends on how the system disk
has been set up), but I have one theory: the display might be going nuts
when the computer tries to display 80-column text.

To confirm this, start up the IIc with no disk in the drive.  When you
see "Check Disk Drive", press Control-Reset.  This will leave you in
Applesoft BASIC, with a ] prompt character and blinking cursor.

Assuming the IIc's "80/40" switch is in its default position (not
pressed), you will be in 40-column mode at this point.  Press the Escape
key, then the "8" key, and the machine will switch to 80-column mode.

If this is working properly, you should just see a narrower prompt and
cursor.  If there is a problem, then you should get a similar "linear
pattern" display (it might look different depending on what text is
actually on the screen).


Assuming this is the problem, then there are two possible explanations:

1. A motherboard fault which is causing the video output signal to go
crazy when 80-column mode is active.

2. The monitor is slightly out of sync.  You might be able to fix it if
you are able to adjust horizontal or vertical hold controls.  Horizontal
is more likely to be the problem.

I'd also suggest trying another monitor.

Let me know what the results are with this experiment.  (By E-Mail, if
you prefer.)

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand