Atari 2600 wont play working games?

[Anthony John Morley]

I couldn't tell hardward or software from any hole so I'll sit back and hope someone else comes along and gives a thumbs up for RIOT chip. From my knowledge of other computers I would assume it is to do with the memory (RIOT) but could be wrong.

 

Interesting that a lot of the games on my not working list have the same characteristics in the code. A common enemy amongst games for me to battle with.

 

Thank you for your help so far. Getting closer to a fix

[SlowCoder]

I couldn't tell hardward or software from any hole so I'll sit back and hope someone else comes along and gives a thumbs up for RIOT chip. From my knowledge of other computers I would assume it is to do with the memory (RIOT) but could be wrong.

I give a thumbs up to trying new chips as a possible solution. I give it a 50% chance.

 

Interesting that a lot of the games on my not working list have the same characteristics in the code. A common enemy amongst games for me to battle with.

Can you explain?

 

Just to add a little more to think about ... you may simply have one of *those* machines. *Those* machines being the ones that, for no particular reason, just won't play certain games. Seems to happen in every type of console. Sort of the anti-Herby to your Volkswagen 2600. If you don't know what I'm talking about, look up Herby the Love Bug movie. They explain this special car as the one-in-a-million of a model car that is very special, with a life of its own.

Edited April 21, 2012 by SlowCoder

[Nukey Shay]

Read the bottom of the previous page.

 

Looking at the software programming of the games he listed as non-working shows that they share the same issue with their code - the last 2 bytes (IRQ vector) point to an invalid address instead of an extra copy of the previous 2 bytes (reset vector). The theory I came up with is that the reset vector is not being used properly by that specific console...so it inadvertantly tries to use IRQ instead whenever a BRK is encountered. Because the IRQ vector is invalid, the machine locks up (i.e. executing an endless loop).

 

The games he listed as working are all using the last 2 bytes as intended (either pointing to reset, or to valid IRQ code).

 

I don't know if this is really the cause, but all the disassemblies I looked at so far - roughly half of both lists - revealed this similarity.

[Pioneer4x4]

Based on my minimal amount of understanding on Nukey Shay's comments, I would look for a short/solder bridge (dead spider) on the board, if it is not a failed chip.

[Anthony John Morley]

Based on my minimal amount of understanding on Nukey Shay's comments, I would look for a short/solder bridge (dead spider) on the board, if it is not a failed chip.

 

I have done this. From what I can see there is no solder bridge or anything. I gave the board a good brush down with a paintbrush. Some dust came off it but nothing else. I have another CX2600U on it way to me purchased from eBay. Same make, model for spares or repair. Worked last time used kind of thing. I will see what I can do from the two. If the board works on that I'll most probably just swap it over into this machine. If I can't get one working out of this, I'll go down the new chip/board route from Best Electronics.

 

I'll keep you posted on a fix when I finally find one

[Anthony John Morley]

Right then. I got my 2nd CX2600U for spare parts today. I tested the board in it first off and it all worked, every game I put in it. I replaced the chips in the other board one by one starting with the RIOT chip. That didn't work. Would still play some games but not the others. Then I replaced the TIA chip. That didn't work either.

 

*As I replaced the chips and put the others in the new board that came today and tested them and all games still worked fine.

 

Finally I replaced the CPU chip and low and behold, all games worked.

 

Now here's the really funny part. I put the old CPU chip into the new board that came today and that board worked fine with all games? Strange.

 

So I'm assuming it was some kind of conflict with that particular chip and the board. Now I have 2 perfectly good, working boards, which is a bonus I guess should one go bad in the future.

 

So there we have it. Fixed. If someone could amend the title of the thread to PROBLEM SOLVED, hopefully this will help someone else in the future.

 

Thank you for all the help over this little problem. Here are some photos of the working games

 

 

 

 

 

 

Edited April 26, 2012 by Anthony John Morley

[Pioneer4x4]

Seriously, I would put them all back, and test again. I bet it was corrosion on a leg of one of the chips, and removal and insertion a couple times fixed it. But hey, 2 2600s when you were hoping to fix one is a good deal.

[Anthony John Morley]

Seriously, I would put them all back, and test again. I bet it was corrosion on a leg of one of the chips, and removal and insertion a couple times fixed it. But hey, 2 2600s when you were hoping to fix one is a good deal.

 

I did try that, and it stopped working again. But it seemed to be only the CPU that made any difference. I tried bending the legs out a bit the first time and then in a bit and it made no difference. Soon as I put the other chip in, working fine.

 

Very strange.

 

Apologies, I forgot to mention that in the above post. It's really baffling

[atari2atari]

 

Finally I replaced the CPU chip and low and behold, all games worked.

 

 

Thank you for all the help over this little problem. Here are some photos of the working games

 

 

 

That's great! Congratulations!

 

That's what I learned a few years ago - - the ICs go bad, and often the problems a 2600 exhibits can all be traced back to a bad chip.

 

 

Does my heart good to see another console flayed open, exposed to the light, and revealing its secrets.

 

Now you need to pick up a soldering iron and get to modding on that puppy - - maybe composite/S-Video/stereo sound output?

 

-a2a

[Anthony John Morley]

Now you need to pick up a soldering iron and get to modding on that puppy - - maybe composite/S-Video/stereo sound output?

 

Maybe one day. For now, it's working as it should and I'm happy with it, apart from the power adapter is a little tempermental, more mental than temper though. I'll have a brand new NOS coming in a day or two so that's fine.

 

This is to show the grandchildren and show them where it all started.....for me anyway

[atari2atari]

Now you need to pick up a soldering iron and get to modding on that puppy - - maybe composite/S-Video/stereo sound output?

 

Maybe one day. For now, it's working as it should and I'm happy with it, apart from the power adapter is a little tempermental, more mental than temper though. I'll have a brand new NOS coming in a day or two so that's fine.

 

This is to show the grandchildren and show them where it all started.....for me anyway

 

Sometimes the power adapter socket on the motherboard where the power input goes in can become worn and/or loose, and so you get inconsistent power.

 

You know you have that situation if you jiggle the power cord in the socket lightly, and the machine resets, or if you twist the power adapter plug, and the machine resets, or doesn't boot in certain rotated positions.

 

Alternately, the metal on the power adapter plug can get worn down, too, and so a NOS adapter could also fix that problem, as well as "tighten" the connection if it is indeed the socket instead.

 

The alternative is to replace the power input socket, which is relatively fast, just a few solder points.

 

 

-a2a

[Anthony John Morley]

Yeah. I know it's not a socket problem as I have another official Atari power supply from the Vader which works fine with this machine. The one that came with it is the original Ingersoll (UK Supply) It has a bit of a rattle to it although the cable seems fine. It kind of gets power surges through it and make the screen go funny, strange vertical lines and loud crackles of sound. If I wiggle it it's fine but for the sake of £10 I've ordered a new.

 

I have a spare socket/board for future now so it's not a problem.

 

[Anthony John Morley]

From what I've read, the original Ingersoll power supplies with the Atari in the late 70's/ealy 80's UK were notoriously.....Shite!

 

One that says Atari on will do me fine

[atari2atari]

AWESOME! Prepare to get your retro game ON!

 

Have fun with that Sixer - - it's my favorite board revision, for sure, although the compact nature of the Junior is nice, too.

 

Welcome to the "family" and to AtariAge!

 

-a2a

[Anthony John Morley]

Thank you.

 

I will have fun. Got a load of games already and looking forward to starting a big collection. I've even got the wife in on it. She never had an Atari while growing up, and now she's loving all the games I keep bringing in. Me and my brothers had a Jnr to share when we kids but I always liked the look of the older style, woodgrain models. Only took me 26 odd year to get one.

 

Just to be able to play River Raid, Q-Bert, and Frostbite again is great enough but I'm slowly discovering more great games I missed while young.

[Anthony John Morley]

*UPDATE*

 

Atari is still working great. Me and the wife have "Atari Night" regular. I got a new NOS power supply and have now bumped the game collection up to 34 with the latest additions of Solar Fox, Breakout, Super Breakout, Asteroids, Smurf and Keystone Kapers.

 

My childhood is being relived and the wife is experiencing something she never had as a child.