Re: I have a prob with a 130XE

From: Michael Current (aa700@cleveland.Freenet.Edu)
Date: 05/22/93-09:29:11 PM Z

From: aa700@cleveland.Freenet.Edu (Michael Current)
Subject: Re: I have a prob with a 130XE
Date: Sat May 22 21:29:11 1993

In a previous article, ck418@cleveland.Freenet.Edu (Karen Ann Hauserman) says:

>I have a 130XE and all the things I need for it, but I realized when I set it
>up that certain keys that were in a diagonal line did not work!  Is there any
>way I can fix this without spending too much cash?  If so, HOW?  Thanks

I just pulled this off of comp.sys.atari.8bit:

 From: (Jim Johnson)

In a message dated Sat 22 May 93  1:03, (david Bry

 DB> I just bought a 600XL yesterday for $10 and the thing works fine
 DB> except for the keyboard. Some of the keys don't work at all and
 DB> there is a definite pattern to which ones work and which
 DB> ones don't, i.e. the keys 3,E,D,C don't work, and they all fall
 DB> on a line on the keyboard. Pulling the keyboard apart revealed
 DB> that the keys that don't work are all connected by one of four
 DB> strips of that white material on one of the plastic strips that
 DB> lie beneath the keys. I looked everything over and couldn't see
 DB> any cracks or breaks in the lines, and cleaning everything off
 DB> didn't seem to help. Can anyone advise me here on what I could do?

There are two possibilities here:
1- There is a break in the circuit
2- You have a bad keyboard decoder chip

1- Pick up a bottle of conductive paint from your local automotive supply
shop. This stuff is used to repair the rear window electric defrosting
grid. Scrape the grid lightly at each key, and paint in the grid.

If this doesn't work, check the circuit from the keyboard, through the
keyboard to motherboard connector, and to the keyboard decoding chip (there
are two chips on the motherboard). You may have to repair the circuit by
running a new wire.

2- You can test the keyboard decoder chip by jumpering between pins on the
chips. The keyboard is a matrix with a key at the intersection of two
wires. By jumpering two pins from the keyboard decoder chips, you are
bypassing the keyboard. It will take some time, but trace the lines from
the keyboard to the chips and try jumpering the pins for the non-working

BTW, with a little arithmetic, you will notice that the keyboard decoder
chips can support more keys than appear on the keyboard. Atari's XL/XE OS
supports the four 1200XL function keys on the entire XL/XE line. I
installed four button switches in a diamond pattern on my 130XE for the
1200XL F1-F4 buttons. In non-shifted mode, these buttons will give you one
key cursor control within most applications. The function keys provide a
variety of other uses when used in combination with Shift and Control keys.

-- Via DLG Pro v0.995
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         Michael Current, Cleveland Free-Net 8-bit Atari SIGOp
Carleton College, Northfield, MN, USA / UUCP: ...!umn-cs!ccnfld!currentm
      Internet: / Cleveland Free-Net: aa700

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