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Ballblaɀer

Quest for Quintana Roo owners: garbled intro screen?

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If you own Quest for Quintana Roo for the 5200, is the first screen garbled when you first turn on the game? Does it go away consistently when you warm-reset (i.e. using the controller, not powering off and on the console)?

 

I'm planning to purchase a copy from Best Electronics, but apparently their entire stock (hundreds?) of new QFQR cartridges has developed the glitch that I've described above. I inquired further, and was told that this started to happen to some of their stock 3 to 5 years ago, but that now all of them suffer from this minor glitch. It does not affect gameplay -- only the initial introductory screen -- and it's resolved by simply resetting the game.

 

The cartridges in question are original stock, using mask ROMs (i.e. this isn't EPROM bit-rot), purchased direct from the Sunnyvale company that manufactured them for Sunrise. According to Best there was only one production run of QFQR and all the game MROMs have the same date code (and are therefore subject to the same ROM problem) so... this should happen to all copies of the game eventually, if it hasn't already.

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Oh man. That blows. I hope there's a solid rom image already available, for future use when the old carts are all datarotted out.

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My QFQR doesn't do this. I just pulled it out of storage and plugged it into my 5200 4-port. Title screen fired up nice and clear on the first try.

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My QFQR doesn't do this. I just pulled it out of storage and plugged it into my 5200 4-port. Title screen fired up nice and clear on the first try.

Mine either and I have the 4 port.

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Very interesting, thanks! This same behavior was reported back in 2010 in Altirra 1.7 as well.

 

I have two different ROMs for QFQR (purely for testing purposes, of course).

 

File #1: 32KB .bin file, dated 10/9/98

Altirra (x64) 2.50 (recommended 32K mapper) - loads correctly

Altirra (x64) 2.70 (recommended 32K mapper) - garbled intro screen

Altirra (x64) 2.80 test 25 (recommended 32K mapper, DRAM1 on power-up) - loads correctly

Altirra (x64) 2.80 test 25 (recommended 16K mapper, DRAM2 on power-up) - garbled intro screen

Altirra (x64) 2.80 test 25 (recommended 16K mapper, DRAM3 on power-up) - garbled intro screen

Altirra (x64) 2.80 test 25 (recommended 32K mapper, random SRAM on power-up) - garbled intro screen

Altirra (x64) 2.80 test 25 (recommended 32K mapper, Cleared memory on power-up) - loads correctly

 

File #2: 16KB .a52 file, dated 10/16/01

Altirra (x64) 2.X0 (16K two chip mapper) - black screen, nothing appears to load (all versions of Altirra)

Altirra (x64) 2.50 (16K one chip mapper) - loads correctly

Altirra (x64) 2.70 (16K one chip mapper) - garbled intro screen

Altirra (x64) 2.80 test 25 (recommended 16K one chip mapper, DRAM1 on power-up) - loads correctly

Altirra (x64) 2.80 test 25 (recommended 16K one chip mapper, DRAM2 on power-up) - garbled intro screen

Altirra (x64) 2.80 test 25 (recommended 16K one chip mapper, DRAM3 on power-up) - garbled intro screen

Altirra (x64) 2.80 test 25 (recommended 16K one chip mapper, random SRAM on power-up) - garbled intro screen

Altirra (x64) 2.80 test 25 (recommended 16K one chip mapper, Cleared memory on power-up) - loads correctly

 

Much of the technical side of this goes above my head, so it's entirely possible I have no idea what I'm talking about, but... given that QFQR is doing something with uninitialized memory that plays a factor in how Altirra handles the title screen display... is it possible that the GTIA and/or DRAM in the 5200(s) Best has been testing the carts with is actually the problem? Or, perhaps it's something specific to certain revisions of the 5200 hardware and how they handle QFQR?

 

Possibly relevant sections of the Altirra Hardware Reference Manual:

3.3 Memory system; Initial memory contents

6.6 GTIA special modes

6.7 Cycle timing; GTIA mode changes

8.1 Cartridge port; Power-on and reset behavior

8.1 Cartridge port; Late hardware reset

Edited by Ballblaɀer

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I actually purchased a copy from best a couple months back. They actually discovered the issue with my personal copy when they tested it before shipment. The reset doesn't always work for me but the good news is that there are absolutely no issues with the rest of the game. It's definitely the cheapest route to go through best and the game is still totally playable.

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I actually purchased a copy from best a couple months back. They actually discovered the issue with my personal copy when they tested it before shipment. The reset doesn't always work for me but the good news is that there are absolutely no issues with the rest of the game. It's definitely the cheapest route to go through best and the game is still totally playable.

 

Thanks so much for chiming in -- can you let me know if you play on a 4-port 5200, or a 2-port? Or both? If you only use a 4-port, can you post your 5200's serial number?

 

At this point I'm mainly curious to figure out what's going on here -- whether this issue is purely cart-based (i.e. something specific in the QFQR cartridge load programming has changed and doesn't want to play nice with hardware), or console-based (I don't know, some kind of DRAM degeneration/problem? some other minor hardware revision playing a factor?). I suspect it's a combination of the two.

 

Given that the ROMs I'm using are 15-20 years old, I'd hope that one or both of them are good dumps from a plays-as-intended cart. So, for both of them to be exhibiting the intro screen garbling issues in various revisions of Altirra... does that perhaps suggest that the QFQR mask ROMs are unchanged, and instead it's the 5200 hardware -- and its initialization of DRAM, in particular -- behaving differently than it did 20-30 years ago? Again, I'm admittedly a total novice when it comes to most of the inner workings, but from what I'm reading in the Altirra thread and in the Altirra reference manual, it seems like unexpected/nonzero DRAM values getting copied into memory are what's throwing off the clock and forcing GTIA mode 11 (producing the unreadable two color "text"). And considering that values in DRAM can be affected by things like how long the console is off... I don't know. Just thinking out loud here.

 

As a small tangent, does anyone know why there are two different size ROMs that both work? I presume that the game itself is 16K, but there's some kind of doubling/mirroring going in in the 32K image. What's actually on Sunrise's cartridge PCB? I couldn't find a photo or discussion of it elsewhere.

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I have tested it on both my 2 port and 4 port systems. My SN # for the 4 port is SV3920022368. Admittedly, I am just now getting back into the 5200 after selling my original 20 years ago but I would be happy to assist in any way I can. Unfortunately my switch on for my 4 port just went out so I will need to replace it but I would be more than happy to test using my 2 port in the mean time.

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Easy test:


Would someone with the garbled screen cart be willing to loan it to someone with the non garbled screen cart (or the other way around) for testing?


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I currently have two QfQR carts and both of them are having this issue on my two port 5200. I know my original cart did not have this issue on the four port I usually use, but it's down for repairs right now. Looking forward to testing both carts when the 4 port is working again (hopefully next week after parts arrive.)

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If it doesn't do this on 4-port units, then I wonder if it is hardware differences, or something that can also be fixed through the use of the 4-port bios when installed into a 2-port 5200 type thing?

 

It was about 2 years ago when I last tested this. I did just an actual 5200 redemption in the mail yesterday, and I suppose using that with a genesis controller and my wico keypad is as good a test for it as any?

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If it doesn't do this on 4-port units, then I wonder if it is hardware differences, or something that can also be fixed through the use of the 4-port bios when installed into a 2-port 5200 type thing?

 

It was about 2 years ago when I last tested this. I did just an actual 5200 redemption in the mail yesterday, and I suppose using that with a genesis controller and my wico keypad is as good a test for it as any?

 

Heh, I got the other Redemption that was sold in the mail yesterday too! :-) *fist bump*

 

As for the QfQR issue, doesn't matter if there's a controller plugged in our not, the screen corruption issue comes up either way. I'm also curious if it's a simply a 2-port BIOS issue... since this isn't a common game, it seems possible to me that the cause is just that simple. We just need more people to confirm that it happens on their 2-ports and/or not on their 4-ports.

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I currently have two QfQR carts and both of them are having this issue on my two port 5200. I know my original cart did not have this issue on the four port I usually use, but it's down for repairs right now. Looking forward to testing both carts when the 4 port is working again (hopefully next week after parts arrive.)

Forgot to get back to this promptly, can now confirm that the into screen displays fine on both of my QfQR carts on my 4-port. Really starting to look like this is a 2-port issue, not an individual cart issue.

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Interesting... I've never run this game on a 2-port deck since I've always run 4-ports. I do have a couple 2-ports and a handful of carts at my vacation house, but that isn't one of them.

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From here: http://atariage.com/forums/topic/246939-altirra-270-released/?p=3477587

 

The issue is that the game reads an uninitialized memory location ($0C) and writes it to a graphics chip register (GTIA register PRIOR).

 

That it's OK on the 4-port but not the 2-port is down to the initial power up state of RAM on the two different systems.

 

On the 4-port the initial power up state is a value (perhaps $00) which doesn't cause an issue when written to PRIOR. On the 2-port it is a value which puts the graphics into GTIA mode 11 (80 pixels wide, 16 hues, 1 luminance), hence you can't read the text.

 

Note that it is not related to the BIOS as the cart runs in diagnostics mode and takes control of the system before any initialisation.

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From here: http://atariage.com/forums/topic/246939-altirra-270-released/?p=3477587

 

The issue is that the game reads an uninitialized memory location ($0C) and writes it to a graphics chip register (GTIA register PRIOR).

 

That it's OK on the 4-port but not the 2-port is down to the initial power up state of RAM on the two different systems.

 

On the 4-port the initial power up state is a value (perhaps $00) which doesn't cause an issue when written to PRIOR. On the 2-port it is a value which puts the graphics into GTIA mode 11 (80 pixels wide, 16 hues, 1 luminance), hence you can't read the text.

 

Note that it is not related to the BIOS as the cart runs in diagnostics mode and takes control of the system before any initialisation.

 

So then it is a specific issue with 2 ports vs 4 ports. Like we speculated but at least now we know why. Wonder why this wasn't discovered until now? You would think something like this would have been found YEARS ago...

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So then it is a specific issue with 2 ports vs 4 ports. Like we speculated but at least now we know why. Wonder why this wasn't discovered until now? You would think something like this would have been found YEARS ago...

 

It is a software bug in the game, just that you get away with it on the 4-port but not on the 2-port.

 

You cannot rely on uninitialized RAM having any particular value, so reading this uninitialized location and writing it to the GTIA register is a bug. The programmer was unlucky that the uninitialized value was OK, otherwise it would have been easily found and corrected before the game was released.

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From here: http://atariage.com/forums/topic/246939-altirra-270-released/?p=3477587

 

The issue is that the game reads an uninitialized memory location ($0C) and writes it to a graphics chip register (GTIA register PRIOR).

 

That it's OK on the 4-port but not the 2-port is down to the initial power up state of RAM on the two different systems.

 

On the 4-port the initial power up state is a value (perhaps $00) which doesn't cause an issue when written to PRIOR. On the 2-port it is a value which puts the graphics into GTIA mode 11 (80 pixels wide, 16 hues, 1 luminance), hence you can't read the text.

 

Note that it is not related to the BIOS as the cart runs in diagnostics mode and takes control of the system before any initialisation.

 

Pleased to see confirmed that my kinda-sorta-informed speculation was on the right track. Thanks for pretty much putting this issue to bed!

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