Problems with Attack of the PETSCII Robots

[prorok]

This past weekend at VCFMW, I picked up a copy of Attack of the PETSCII Robots from David Murray, The 8-Bit Guy. I fired it up today, ran in to problems, contacted David and he's pointed me to y'all.

 

I get the initial color Atari logo and get to the next screen of detecting human presence, but when it segues to the title screen and kick off the POKEY music, it crashes. Usually it plays some tone with a solid color screen, then sometimes after a few second changes to another color screen and another tone. Sometimes I just get a black screen and no tone.

I don’t have this problem with any of the other several dozen 7800 carts and countless 2600 carts I have, though this is my first ever cart with a POKEY soundtrack.

My 7800 is lightly modded (nothing too exotic): UAV for composite video mod, blue power LED, and a standard barrel connector for the power adapter. I guess it’s possible the UAV is causing me trouble, but I suspect the Venn diagram of UAV modded 7800’s and PETSCII Robots has some decent overlap.

I *did* read the friendly manual and the insert, but found no hints.

Obviously tried reseating the cart a few times, but no love.

Any thoughts for next steps?

Thanks for your help!

 

Dan in Austin

[Albert]

Oh, interesting, I didn't know David was selling copies of the 7800 PETSCII Robots at VCFMW. 

 

Sorry to hear you're having problems with the game, I do test all of them before I even put labels on the game, and I make sure to start a new game after the game has booted.  The only thing I could suggest is to try cleaning the contacts using isopropyl alcohol, as I've definitely had failures of the game (and games in general) if the contacts are dirty.   Outside of that, I'm not sure why it would fail, the game has been pretty reliable and there are a lot of copies out there now.  If cleaning the contacts doesn't work, I'll be glad to replace the cartridge, of course.

 

 ..Al

[Mayhem]

Next step really, try it on another 7800.

[Albert]

12 minutes ago, Mayhem said:

Next step really, try it on another 7800.

I don't think that's an option for most people.

 

 ..Al

[GranitePenguin]

Prorok and I were discussing options for troubleshooting before landing here, and "try another 7800" was, indeed, thought of.  We also thought "try a cart with a POKEY chip" to see if a real POKEY works in the one 7800 he has.  Neither option is easy to do when someone does not have a collection in the basement.  It's not like we didn't think to try it, but buying more hardware just to see if a cart is bad isn't a good financial plan.  It seemed to make more sense to first ask "has anyone seen this?" before throwing $$$ at it.

Edited September 14, 2023 by GranitePenguin
clarification of using a real POKEY

[prorok]

42 minutes ago, Albert said:

I don't think that's an option for most people.

 

 ..Al

...but, given that I live in the Hill Country, it might be for me if you're willing to meet up for some debugging.

[prorok]

I broke out my 1Up card and some IPA to clean the game contacts (that looked pretty darned clean to begin with) and no change in behavior. I ordered some Dioxit from the almighty Amazon I can try spraying in the cart slot when the order arrives this weekend. At least the failure mode is consistent.

[Albert]

Just now, prorok said:

I broke out my 1Up card and some IPA to clean the game contacts (that looked pretty darned clean to begin with) and no change in behavior. I ordered some Dioxit from the almighty Amazon I can try spraying in the cart slot when the order arrives this weekend. At least the failure mode is consistent.

Great, thanks for trying that out.  It is nice when that fixes the problem, but obviously you can't expect that to fix it. 

 

..Al

[GranitePenguin]

2 minutes ago, Albert said:

Great, thanks for trying that out.  It is nice when that fixes the problem, but obviously you can't expect that to fix it. 

 

..Al

Do you know if there are specific contacts in the card slot that are dedicated to the POKEY? I'm assuming there are, and they would be mostly unused/untouched leading to contacts that don't get normal wear.  If that's crusty, that could explain why normal carts work and PETSCII isn't.  The cart *does* start normally and doesn't die until it presumably tries to access the HOKEY.

[Albert]

For POKEY support, there's an audio line going from the cartridge to the system, but that wouldn't prevent the cartridge from working.  The music doesn't begin until you get to the title screen, but there is audio on the very first screen as the text is being drawn.  Not sure if that's TIA or POKEY audio off the top of my head.

 

 ..Al

[GranitePenguin]

8 minutes ago, Albert said:

For POKEY support, there's an audio line going from the cartridge to the system, but that wouldn't prevent the cartridge from working.  The music doesn't begin until you get to the title screen, but there is audio on the very first screen as the text is being drawn.  Not sure if that's TIA or POKEY audio off the top of my head.

 

 ..Al

So you mean at this point there should be sound of some kind (just not any music)?  Prorok sent me a video clip and it's silent during this part before it either goes black, or locks up on some garbled tone   

[Albert]

Yes, while that text being drawn, there's a sound that repeats.  You also have garbage in the AtariAge graphic at the bottom, and that obviously should not be happening.  I just need to get a new carts out to Prorok. 

 

 ..Al

[prorok]

You may not hear it on the video but the ping-like sounds are produced as the text is printed.

[+-^CrossBow^-]

2 minutes ago, GranitePenguin said:

So you mean at this point there should be sound of some kind (just not any music)?  Prorok sent me a video clip and it's silent during this part before it either goes black, or locks up on some garbled tone   

Yes...it plays a sound as the text comes onto the screen during this part. I think that part is TIA. Also, as @Albert correctly stated, most games that use POKEY are only using it for music/sound. And so they will come up and still work minus the audio even if the Pokey is removed. I've a few Ballblazer carts that prove this.

 

[GranitePenguin]

2 minutes ago, -^CrossBow^- said:

Yes...it plays a sound as the text comes onto the screen during this part. I think that part is TIA. Also, as @Albert correctly stated, most games that use POKEY are only using it for music/sound. And so they will come up and still work minus the audio even if the Pokey is removed. I've a few Ballblazer carts that prove this.

 

Interesting.  I wonder if a removed Pokey would behave differently than a damaged one?  I don't really know anything about the Pokey architecture.  I guess it would probably produce garbled tones instead of being silent.

[GranitePenguin]

6 minutes ago, Albert said:

Yes, while that text being drawn, there's a sound that repeats.  You also have garbage in the AtariAge graphic at the bottom, and that obviously should not be happening.  I just need to get a new carts out to Prorok. 

 

 ..Al

I didn't pick up on the garbage in the logo.  I guess a picture really is worth 1000 words. :-)

[+-^CrossBow^-]

4 minutes ago, GranitePenguin said:

Interesting.  I wonder if a removed Pokey would behave differently than a damaged one?  I don't really know anything about the Pokey architecture.  I guess it would probably produce garbled tones instead of being silent.

Maybe... I actually have a pokey I pulled from a 5200 that is bad in that controller functions no longer work off that chip. However, the audio and random number generator are fine on it, so I put it into a ballblazer and it works and sounds fine? So I'm pretty sure in the case of the 7800 games, that really only the audio stuff in the Pokey is being used. So if the pokey weren't working at all, it would likely be silent or possibly messed up sounds. But it could also be messed up enough to actually cause issues with the game loading too I suppose. Then again...I thought all of the 7800 Petscii cartridges have HOKEYs in them? Pretty sure mine has a HOKEY installed in it and I bought mine at Portland Expo last year.

 

[Albert]

Removing a POKEY chip from a 7800 game just makes the game run in silence (outside of any TIA audio).  I've done this many times with various games that have POKEY audio. 

 

 ..Al

[GranitePenguin]

4 minutes ago, -^CrossBow^- said:

Maybe... I actually have a pokey I pulled from a 5200 that is bad in that controller functions no longer work off that chip. However, the audio and random number generator are fine on it, so I put it into a ballblazer and it works and sounds fine? So I'm pretty sure in the case of the 7800 games, that really only the audio stuff in the Pokey is being used. So if the pokey weren't working at all, it would likely be silent or possibly messed up sounds. But it could also be messed up enough to actually cause issues with the game loading too I suppose. Then again...I thought all of the 7800 Petscii cartridges have HOKEYs in them? Pretty sure mine has a HOKEY installed in it and I bought mine at Portland Expo last year.

 

My understanding is it's using a HOKEY, yes.  I was asking more in the context of what a real POKEY is actually designed to do under normal circumstances (eg, what a broken one in Ballblazer would do).  Since the HOKEY is meant to replace a POKEY, I assume it's using the same connection to the 7800 that a POKEY would have used.

 

[+-^CrossBow^-]

12 minutes ago, GranitePenguin said:

My understanding is it's using a HOKEY, yes.  I was asking more in the context of what a real POKEY is actually designed to do under normal circumstances (eg, what a broken one in Ballblazer would do).  Since the HOKEY is meant to replace a POKEY, I assume it's using the same connection to the 7800 that a POKEY would have used.

 

The hokey is only replicating the audio portions of the Pokey. it doesn't do any of the serial communication stuff as again, that was all specific to POKEYs being used in the Atari computers and the 5200. The Hokey doesn't even have all of the pins on them as a normal POKEY since again, it only needs what is needed for the audio portion to work that it simulates.

 

So even if you had an issue with your HOKEY I don't think it would prevent the game from working and would just be silent when the music would kick in. The crashing you are experiencing with the game, I do NOT believe is related to the HOKEY side of things and is likely just something with your cart. Again, Al can replace it out as he has offered and go from there.

 

[RevEng]

14 hours ago, Albert said:

Not sure if that's TIA or POKEY audio off the top of my head.

The text click is TIA audio.

[+batari]

Yes, that is a bad cart, as the glitchy logo reveals that fact

[prorok]

Update for those following along at home...

Al was kind enough to send me another cart and, unfortunately, it fails in exactly the same way, including the logo corruption.

 

Obviously, my attention is now very focused on my console. I'm now giving a stern look at my power supply. My 7800 is modded to accept a standard 2.1mm x 5.5mm barrel connector and I'm using whatever (supposedly) 9VDC / 1A power supply the modder sent to me when I purchased the console some years ago. While I have never had problems with other carts, I have no other home-brews or stock carts with a lot of additional on-cart hardware (such as a HOKEY or a POKEY). My current theory is that the power supply is not fit for purpose.

 

I've ordered a 9VDC / 2500 mA Triad Magnetics power supply to try out as my next cheapest option as I debug.

 

Thank you, all, for the suggestions.

 

Tune in next week for the next installment to this drama. 🙂

[+-^CrossBow^-]

1 hour ago, prorok said:

Update for those following along at home...

Al was kind enough to send me another cart and, unfortunately, it fails in exactly the same way, including the logo corruption.

 

Obviously, my attention is now very focused on my console. I'm now giving a stern look at my power supply. My 7800 is modded to accept a standard 2.1mm x 5.5mm barrel connector and I'm using whatever (supposedly) 9VDC / 1A power supply the modder sent to me when I purchased the console some years ago. While I have never had problems with other carts, I have no other home-brews or stock carts with a lot of additional on-cart hardware (such as a HOKEY or a POKEY). My current theory is that the power supply is not fit for purpose.

 

I've ordered a 9VDC / 2500 mA Triad Magnetics power supply to try out as my next cheapest option as I debug.

 

Thank you, all, for the suggestions.

 

Tune in next week for the next installment to this drama. 🙂

Another possibility here because I ran into this with Popeye 7800 on at least one console. You might see if your have the extra timing circuit enabled on your 7800. If so, disabling it might improve things. Also, unless the voltage regulator in your 7800 was also replaced with a higher output variant, using a beefier power supply won't do much if the regulator inside is still only rated for 1A output to the console.

 

In any event, I'm happy to look at your console as I've got two versions of Petscii Robots here I could use to test with it and see if I can find out what's going on.

 

[prorok]

24 minutes ago, -^CrossBow^- said:

Another possibility here because I ran into this with Popeye 7800 on at least one console. You might see if your have the extra timing circuit enabled on your 7800. If so, disabling it might improve things. Also, unless the voltage regulator in your 7800 was also replaced with a higher output variant, using a beefier power supply won't do much if the regulator inside is still only rated for 1A output to the console.

 

In any event, I'm happy to look at your console as I've got two versions of Petscii Robots here I could use to test with it and see if I can find out what's going on.

 

Thanks, CrossBow, for suggestions on next steps.

 

My first guess is that my so-called 1A power supply isn't actually putting out up to 1A, or its slew rate is so slow, it's not ramping up fast enough for a rising current draw. If problems continue after I try the overkill power supply, you make a good point that the voltage regulator is the next piece that take a good look at.

 

To some extent, solving this mystery is at least as much fun as playing the games themselves. We'll solve this puzzle eventually.

 

Dan

 

Edited September 24, 2023 by prorok