Kaypro 2X starts up with silly display

From: Christopher Cureau <chrisc_at_addpower.com>
Date: Fri Oct 31 15:48:46 2003

For what it's worth, when this sort of thing happened with a Commodore, it
usually meant one of the ROMs had a problem. I never did own a Kaypro,

                    Otto-Adamczak To: "General Discussion: On-Topic Posts Only" <cctech_at_classiccmp.org>
                    <toa7d3_at_arcor.de> cc:
                    Sent by: Subject: Re: Kaypro 2X starts up with silly display
                    10/31/2003 02:58 PM
                    Please respond to
                    On-Topic Posts

Here are a few more details regarding the problem:

I didn't start my Kaypro 2X for several years. Some weeks ago I gave it
a short try and everything seemed to be okay except for the keyboard.
Due to corrosion many keys didn't react. So I gave it to a friend, who
first tested all the keys to see which were in need to be cleaned. The
display was still okay at that time. Then he opened the keyboard and
cleaned the contacts inside the keyswitches (he had to solder them out
in order to do that). When he had finished the cleaning he assembled and
reconnected the keyboard and started the computer. From that time the
display went silly:

- The powerup message shows up at random coordinates, however some of
the coordinates are okay (see
http://home.arcor.de/toa/tmp/kaypro-defekt.jpg). There are a lot of
additional characters, most of them are '?' (n with ~ above). A few of
the characters are blinking or show up with low intensity. Effect is the
same with or without keyboard connected. Everytime I hit the reset
button I see another random distribution.

- When you type something on the keyboard (at the CP/M prompt) the
characters show up at random coordinates but the blinking cursor moves
in the way one would expect (one step to the right for each character,
3rd position of new line when you hit return). W/o any keyboard input
the display is stable except for the blinking chars.

- When you type in CP/M commands (I still have all the disks) they get
executed but the output characters show up at random coordinates (see
http://home.arcor.de/toa/tmp/kaypro-dir.jpg for an output of "dir").

Has anyone schematics for the Kaypro 2X?
Any hints what to do next?

Received on Fri Oct 31 2003 - 15:48:46 GMT

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