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Concerto and 7800 no Bueno


Goochman

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In order to not clog up any Concerto threads I wanted to see if there was obvious on my 7800 which renders it not compatible with the Concerto.  I have about a 20% success rate on any of the BIOS that have been loaded.  Game sometimes work and most times not.  I try Ballblazer to see if my Pokey chip is working - nothing.  PacMan homebrews, sound tests, nothing.  The Diagnostic cart seems to work most of the time I run it.

 

Ive tried a variety of 7800 and 2600 carts.  2600 carts generally work but a few fail to load.

 

Im lookinng to see if there is something I can run/try that might help pinpoint why I have such little success.

 

Im attaching pictures of the inside of my unit (The RF Shield is not fun..............)

 

 

 

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What version of the firmware does it show at the top of the screen:  "Concerto firmware ?????"

 

*EDIT:  It appears, from when you post previously to the Concerto firmware thread.. 

Quote

I have a stock NTSC 7800 that most likely  will never work 100%, however with the new firmware it seemed to be more "consistent".  A number of 7800 games worked first try like Commando and Centipede.  Baby Pac Man and Beef Drop did not - however the issue was the screen lock was the same each time - no variance like on the previous firmware.

..you are running the latest firmware from May 27th, "0.95test_dmaoff".

 

From another post, prior to the above, in that thread:

Quote

Commando and Beef Drop (RIP Ken) also worked - but my cart connector is flaky.  I was 3 levels into Beef Drop when it locked up on me

:( - any reasonable fix for this?  If the cart isnt just right in the slot then it wont load or may lock up while playing.  A slight jiggle and best guess straightening of cart usually fixes it.

Commando working, as mentioned in the above quotes, but Ballblazer not working, as stated in the O.P. of this thread, there is something definitely odd about those results.  If the console's cart connector is the same flaky one, it sounds like it could very well be the culprit, or at the very least, a significant factor.

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Thanks Trebor - I did an Isopropyl alcohol cleaning of the cart connector awhile back and it seemed to make things worse.  Ill perform the diagnostic test again and let sit for 20 mins and try running a few 7800 carts again.

 

I am running the last firmware that Fred posted.

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5 hours ago, Trebor said:

What version of the firmware does it show at the top of the screen:  "Concerto firmware ?????"

 

*EDIT:  It appears, from when you post previously to the Concerto firmware thread.. 

..you are running the latest firmware from May 27th, "0.95test_dmaoff".

 

From another post, prior to the above, in that thread:

Commando working, as mentioned in the above quotes, but Ballblazer not working, as stated in the O.P. of this thread, there is something definitely odd about those results.  If the console's cart connector is the same flaky one, it sounds like it could very well be the culprit, or at the very least, a significant factor.

I agree that Commando working (which is a 128k game) and Ballblazer (32k) not working is a strange outcome. It does not sound like the loading problems that were improved with the latest firmware, because the problem was worse with larger games. It sounds to me like a possible hardware issue with your Concerto.

 

@Goochman, to rule that out, PM me so I can replace your Concerto with a new one.

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Thanks Fred - I sent you a PM.  Another reason for me posting this msg is Ive seen where certian 6502 or other chips are known offenders working with the Concerto so I wanted to see if any of my chips fall into that category.

 

Also - if it turns out the cart port is loose/not making contact are there any solutions which might help that dont involve soldering?

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1 hour ago, Goochman said:

Thanks Fred - I sent you a PM.  Another reason for me posting this msg is Ive seen where certian 6502 or other chips are known offenders working with the Concerto so I wanted to see if any of my chips fall into that category.

 

Also - if it turns out the cart port is loose/not making contact are there any solutions which might help that dont involve soldering?

Yes you have a Rockwell CPU and it is at least known to have some issues. However, I've been told that an AA member having issues, attached a heatsink and a fan to the 6502 and were then able to play stuff much more stable. So if you at least have some canned air and can do a freezing on the CPU to see if that helps, it would at least narrow down the cause as possibly due to heat buildup. Not saying that is the same issue here with the Concerto as I haven't one of my own but just some information I've been told in the background.

 

Another thought since you said Commando works but BB doesn't. What does BB do exactly when you try and run it?

 

 

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Here is the latest testing:

Both Diagnostic programs I tried to run didnt work

Barnyard Blaster and Commando got to the title screen.  When pressing SELECT the screen froze

After the screen froze I could not get to the title screen again.  After some color cycling it stopped on a blue screen and froze (The next step is to run the cart)

Xenophobe and Summer Games stop at blue screen after a period of flashing

Xevious doesnt even color cycle - just black screen after selecting

Ball Blazer and Choplifter didnt get very far in their load process - the screen color changed maybe once or twice and stopped on this maroon color

Crossbow 7800 worked :)

 

On the 2600 side I tried:

Dodge 'Em - first try got freeze screen, second + tries worked

Q*Bert - Worked first try

Centipede - like Dodge 'Em froze first try then worked

 

I seem to get random results when I run the cart - most times stuff not working.  Maybe there is a "heat" issue since once it wont get past the blue screen it never does.

 

Pictures of my results below:

 

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06_Barn1.png

07_Barn_Lock.png

08_Commando_Lock.png

09_2600_Lock.png

10_Crossbow.png

11_blue_Lock.png

12_maroon_Lock.png

Edited by Goochman
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Try the 7800 Utility cart. If that comes up, try the cartridge integrity test and let that run. Basically that test as I understand it is reading data from the cartridge over and over and comparing with what it should be in active RAM. So it is a good test to use for picking up timing issues between the cartridge data to the system and was pretty helpful during the initial batch of troubleshooting the Concerto to get it where it is today.

 

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Unsure how it's related to a possible Concerto or/and console issue, but that Diagnostic Cart result screen does not appear correctly:

 

03_Diag1_Screen.png.08074dbde2300f4e7128ce9415977c2b.png

 

It is definitely flagging, demonstrating a problem is present.

 

It should appear like this:

 

image.png.10b9465fe10d4a6a2956879be76a5544.png

 

From the most extensive write up I have come across concerning the cartridge - thank you John Harvey - we know this much:

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Note that there are also other errors that are not caught with an "error code". For example, on the first screen where it says "7800 PRO SYSTEM DIAGNOSTIC TEST VERSION 1:00", you can also somehow trigger text that says " BAD!!!!!". This is found at $EB87, the third chunk of character map data, to be stored at $191E.

Unfortunately, it's not much to go on here.

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Well now everything works.............there is possibly one interesting thing from the Utility cart memory test showing a few dots - not sure wha that means.

 

What was the fix (possibly) - I wedged a business  card at the top of the cart and everything runs first time 99% of the time.

 

Assume this means a bad cart connector?

 

 

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Those dots at the end of the integrity test are normal. I believe that is reserved RAM segments that can't be written to and are used by the system for operations.

 

And yes, if wedging something in like that makes everything work, then you have worn out contact on your cartridge port connector on the mainboard. I've managed to carefully pull them outward towards the center again using a dental pick like tool but it requires some patience and again, being careful to not bend them too much or break them in the process.

 

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  • 3 weeks later...

To wrap this thread up I took Crossbow's suggestion and bought a dental pick from Amazon for $10:

https://www.amazon.com/gp/product/B078R7ZX1W/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1 

 

It was a PIA with a real dental pick is prob a bit too big to get in there (was not easy for me) - anyhow I pulled a few of the pins out and it appears to have fixed my random freeze issue.  Ive had no problems starting pretty much every game Ive tried.  Only odd thing is it appears 2600 Venture with a pokey chip installed doesnt work.  This happened with the preprod and prod carts.

Edited by Goochman
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1 hour ago, scottz29 said:

I just read this entire post, and I thought the same thing:  bad cart connector.  Bent pins on the inside of the connector, or even cold solder joints on the connector pins on the bottom of the PCB, or both.

 

Don't bend the pins first!! Touch up all solder joints for the cartridge connector on the underside of the circuitboard, if that doesn't resolve the issue, THEN bend the pins.

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