Atari 800XL keyboard question
John Marks
I am new to this newsgroup. I just bought an Atari 800 XL computer
with a 1050 disc drive at a thrift shop. When I hooked it up to a TV, I
noticed that the numerical keys 7, 8, 9, and 0 do not work! Has this
happened to anyone else? Does it have anything to do with the cartridge
slot door? I say this because the doors position kinda coorelates with
the position of the numerical keys that don't work. Any help would be
appeciated. I don't want to open up the box if there is another
solution besides cleaning the contacts.
Thanks!
--
John Marks
Jupiter, FL
e-mail: mar...@flinet.com
homepage: http://www.flinet.com/~marks7
Aaron
>Hello,
> I am new to this newsgroup. I just bought an Atari 800 XL computer
>with a 1050 disc drive at a thrift shop. When I hooked it up to a TV, I
>noticed that the numerical keys 7, 8, 9, and 0 do not work! Has this
>happened to anyone else? Does it have anything to do with the cartridge
>slot door? I say this because the doors position kinda coorelates with
>the position of the numerical keys that don't work. Any help would be
>appeciated. I don't want to open up the box if there is another
>solution besides cleaning the contacts.
>Thanks!
The cartridge slot is in no way responsible for a keyboard problem on
the Atari 800XL.
Here's a few suggestions for keyboard repair. All require the need to
unscrew and disassemble the outer case. Once that's done check the
following:
NOTE: not all Atari keyboards are created equal. Suggestion number (1)
should work with all. But suggestion (2) and later will only work with
the "membrane" style of keyboards.
1) There's a flimsy "ribbon" cable connecting the keyboard to the
computer's motherboard. Very gently, pull this cable out of the
motherboard and clean the exposed contacts (spit and toilet paper
should do). Reseat the cable into the motherboard and see if the
offending keys work properly.
If the above doesn't work then proceed below.
2) The keyboard is screwed onto a metal plate which applies pressure
to a hidden plastic membrane containing the actual circuit traces.
Sometimes these traces and the bottoms of the individual keys need to
be cleaned (with spit and toilet paper?). Find yourself a small
screwdriver and proceed to unscrew the two dozen tiny screws located
on the metal plate. BE CAREFUL NOT TO LOSE THEM. Once everything is
exposed, proceed to clean the entire plastic membrane and the
offending key bottoms. Find yourself a piece of tinfoil and roll it up
into a ball. It will be used to test the individual contacts on the
membrane. Turn on the computer and press the tinfoil over the area of
the membrain were the nonworking keys would align to. If the letters
or numbers appear on the screen then you've probably fixed it and you
can proceed to screw everything together.
If the above didn't work then a trace on the plastic membrane may have
degraded. Check the traces for areas that don't appear fully formed
(this'll take a while). If found, you'll have to purchase a special
"conductive" paint to reform the traces. It can be found at most
automotive stores as part of a window defroster kit. It costs between
$8 and $15.
Let me know what happens. My Email addres is aar...@localnet.com
mst...@geocities.com
John, something I have found that tends to fix keyboard problems on the
600XL/800XL systems is to reseat the cable that runs from the keyboard to the
motherboard. That cable can "wiggle" itself loose over time, and cause
problems that are similar to the one you mentioned.
You have to be careful when you disassemble the 800XL. If I remember
correctly, the keyboard cable is VERY fragile, and tears if pulled too hard.
You will also need to contend with an RF shield, but that shouldn't be a
problem as long as you have a pair of needle-nose pliers to deal with the
metal tabs.
I hope you enjoy your XL as much as I have enjoyed mine!
Mike Stulir
Back In Time -- Updated news and complete coverage of ALL things Atari.
http://www.emuclassics.com/backintime
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Jason Hedrick
With the replies about removing the ribbon connector from the
motherboard, I want to give you this additional word of caution, if it's not
too late. When you look at the motherboard where the ribbon cable from the
keyboard attaches, you'll see a connector attached directly to the
motherboard. Way back in my early years, when I got my first Atari, a 600XL,
I thought that the connector was a permanent part of the ribbon, and that
the CONNECTOR slid off the motherboard. IT DOESN'T. The cable is gently
pulled out of the connector. When you pull it out, you'll have JUST a ribbon
cable with bare contacts on the end. That's it!
Jason Hedrick
John Marks wrote in message <36A6F2...@flinet.com>...
>Hello,
> I am new to this newsgroup. I just bought an Atari 800 XL computer
>with a 1050 disc drive at a thrift shop. When I hooked it up to a TV, I
>noticed that the numerical keys 7, 8, 9, and 0 do not work! Has this
>happened to anyone else? Does it have anything to do with the cartridge
>slot door? I say this because the doors position kinda coorelates with
>the position of the numerical keys that don't work. Any help would be
>appeciated. I don't want to open up the box if there is another
>solution besides cleaning the contacts.
>Thanks!
Chris Gill
>happened to anyone else? Does it have anything to do with the cartridge
Clean the contacts before they corrode unfortunatly... if they are corroded,
you can buy a pen from an electronics store (wiseman's here, i don't know
what the equivalent is where you are) that can be used where the carbon
tracking is damaged
Aaron
<Terrance....@DaytonOH.NCR.COM> wrote:
>John,
> With the replies about removing the ribbon connector from the
>motherboard, I want to give you this additional word of caution, if it's not
>too late. When you look at the motherboard where the ribbon cable from the
>keyboard attaches, you'll see a connector attached directly to the
>motherboard. Way back in my early years, when I got my first Atari, a 600XL,
>I thought that the connector was a permanent part of the ribbon, and that
>the CONNECTOR slid off the motherboard. IT DOESN'T. The cable is gently
>pulled out of the connector. When you pull it out, you'll have JUST a ribbon
>cable with bare contacts on the end. That's it!
>
That's a good tip. Also, try to use both hands (and not two left feet
:-) when pulling out the cable from the motherboard.
Paul Nurminen
I've had many Atari 8-bits over the years (my first being an 800XL back in
1983/1984). Anyway, I still have most of my collection, and I recently picked
up another 800XL and 1050 (and several cables) at a Goodwill for $10.
Well, the keyboard in the Goodwill 800XL had a stuck letter "I", so I opened
it up, and replaced the bad keyboard with my original (the one I've had since
the beginning) 800XL keyboard - since my original 800XL only shows a bright
green screen when powered up [any ideas what's wrong?]
Anyway, the point is, my original 800XL keyboard was simply connected with the
ribbon cable to the mother board. That's it.
The Goodwill 800XL was also connected with the ribbon cable, but had 2 wires
soldered to the screws that hold the cartridge port "doors" on, and they were
also soldered together, and then 1 wire went to a screw on the keyboard
assembly itself, and the other to the mother board. What are these for
anyway!?
BTW: The keyboard swap worked fine.
-Paul
--
Paul Nurminen (aka Nurmix)
_/ Red Light 6 Studio - El Segundo, California
* SPAM ALERT!
* (If it's there) remove "NO_SPAM_ME" before e-mailing!
Aaron
>ribbon cable to the mother board. That's it.
>
>The Goodwill 800XL was also connected with the ribbon cable, but had 2 wires
>soldered to the screws that hold the cartridge port "doors" on, and they were
>also soldered together, and then 1 wire went to a screw on the keyboard
>assembly itself, and the other to the mother board. What are these for
>anyway!?
Simple grounding. Removing those connections would more than likely
not affect the computer (except for, possibly, introducing more
interference on the TV display).
There were at least three slightly different models of the 800XL, each
of which, I believe, was manufactured by a different plant.
Jon Melbo
Nurminen) wrote:
>The Goodwill 800XL was also connected with the ribbon cable, but had 2 wires
>soldered to the screws that hold the cartridge port "doors" on, and they were
>also soldered together, and then 1 wire went to a screw on the keyboard
>assembly itself, and the other to the mother board. What are these for
>anyway!?
Sounds like a grounding set up.
Richard Cortese
>
> I was just wondering...
>
> I've had many Atari 8-bits over the years (my first being an 800XL back in
> 1983/1984). Anyway, I still have most of my collection, and I recently picked
> up another 800XL and 1050 (and several cables) at a Goodwill for $10.
>
> Well, the keyboard in the Goodwill 800XL had a stuck letter "I", so I opened
> it up, and replaced the bad keyboard with my original (the one I've had since
> the beginning) 800XL keyboard - since my original 800XL only shows a bright
> green screen when powered up [any ideas what's wrong?]
>
> ribbon cable to the mother board. That's it.
>
> soldered to the screws that hold the cartridge port "doors" on, and they were
> also soldered together, and then 1 wire went to a screw on the keyboard
> assembly itself, and the other to the mother board. What are these for
> anyway!?
>
>
devices, green screen or any screen for that matter, means at least your
clock signals are working so your GTIA & probably Antic are fine.
Blue screen with noise probably means your Pokey is kaput.
The XLs IIRC will boot fine even with a broken PIA, just they won't read
joysticks, etcetera.
I am thinking a green screen may mean a broken 6502C. At least that is
where I would start. It is a special 6502, not an off the shelf part, so
you have to substitute if you can.
I am also the purveyor of a slightly goofy theory. Chemist by trade so I
have a tendancy to look for that as a solution.
I think slightly different compositions in the tinning on chip leads &
the sockets they go into has a tendancy to produce oxides/galvonic
cells, that kind of thing.
Try leaving the computer on overnight, then cycling the power a few
times. That should get rid of any inadvertant 'cells' that could have
formed.
Jon Melbo
<rico...@netmagic.net> wrote:
>I am also the purveyor of a slightly goofy theory. Chemist by trade so I
>have a tendancy to look for that as a solution.
>
>I think slightly different compositions in the tinning on chip leads &
>the sockets they go into has a tendancy to produce oxides/galvonic
>cells, that kind of thing.
>
>Try leaving the computer on overnight, then cycling the power a few
>times. That should get rid of any inadvertant 'cells' that could have
>formed.
You are certainly correct about different metals in contact,
especially with a current flow present causing stuff like that. I
think the best cure for that is to remove chips from their sockets and
put them back in. It helps to spray electrical contact cleaner in and
on before putting the chips back too. The mechanical friction of
removing and reinserting the chips tends to scrub off some of that
crud and also seats chips which may have "crept" loose due to thermal
cycling.
Paul Nurminen
>Just my op. I am not really a hardware guy. But of your 40 pin LSI
>devices, green screen or any screen for that matter, means at least your
>clock signals are working so your GTIA & probably Antic are fine.
>
>Blue screen with noise probably means your Pokey is kaput.
>
>The XLs IIRC will boot fine even with a broken PIA, just they won't read
>joysticks, etcetera.
>
>I am thinking a green screen may mean a broken 6502C. At least that is
>where I would start. It is a special 6502, not an off the shelf part, so
>you have to substitute if you can.
>
>I am also the purveyor of a slightly goofy theory. Chemist by trade so I
>have a tendancy to look for that as a solution.
>
>I think slightly different compositions in the tinning on chip leads &
>the sockets they go into has a tendancy to produce oxides/galvonic
>cells, that kind of thing.
>
>Try leaving the computer on overnight, then cycling the power a few
>times. That should get rid of any inadvertant 'cells' that could have
>formed.
Thanks for the tips. I'll see what happens after leaving the thing on all
night. And if I do decide to swap the CPU (or other chips) does Best or B&C
sell KITS [with several of the 8-bit chips] or do they just sell the
individual chips by themselves?
Richard Cortese
was offering discounts for full chip sets.
Another posibility to get a 5200 game system. The LSI chip sets are
identical with the exception of a missing 6520<?> PIA on the 5200.
Everytime I see a 5200 in a thrift shop or surplus electronics shop I
usually buy them for parts. 90% of the time 5200 system was junked
because of problems with the power supply or joysticks, I used to know
someone in Atari Customer Service<grin>, so the electronics are fine.
Matter of fact, I have 1 or 2 5200 motherboards right now. If you still
have problems with your system and or getting an order in to Best, let
me know.
jacobca...@gmail.com
> Hello,
> I am new to this newsgroup. I just bought an Atari 800 XL computer
> with a 1050 disc drive at a thrift shop. When I hooked it up to a TV, I
> happened to anyone else? Does it have anything to do with the cartridge
> the position of the numerical keys that don't work. Any help would be
> appeciated. I don't want to open up the box if there is another
> solution besides cleaning the contacts.
> Thanks!
> --
> John Marks
> Jupiter, FL
> e-mail: mar...@flinet.com
> homepage: http://www.flinet.com/~marks7