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A Non-Interactive Title Screen is a Safe Screen


Trebor

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Are you wondering if it will fit?  Do you think you are crossing a line that should not be crossed?  Fear not.  Now there's Screen Safe.  Screen Safe provides the boundaries you need to know, when you are pushing things beyond safe places. 

 

image.thumb.png.4ed6506e805bba7d0c86860dbe48da28.png

 

As Shown On TV, it comes completed with zoned scanline measurements!

 

Availability:
- Right here - Screen Safe (20210312).a78
- Latest 7800basic release 'samples' folder
- Coming Soon to Trebors 7800 ROM PROPack

 

As an additional bonus, to be set as the default ROM of the magnificent MiSTer 7800 core, you can obtain your very own standalone copy of a verified screen safe compliant, 7800 Non-Interactive Title Screen...

 

  

Grab your copy today...  7800 Non-Interactive Title Screen (20210320).a78

 

Thanks to @RevEng for both provisions! 

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My usual retrogaming TV. Not bad for a basic consumer set from the early 00’s. A minor geometry issue at the top right but not bad and generally not an issue for a real game. Considering I got this set 5 years ago for the low, low price of “Please, just get this dinosaur out of my house!”, I really can’t complain. :) 

 

548593D1-02F7-4E14-A0D3-7CE7EA83B575.jpeg

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55 minutes ago, RevEng said:

That's a good idea. I've been planning a re-write of the utility cart for a while now, and this would fit in well. :thumbsup:

I know you have and once you are done with it... I need it on a physical cart?! LOL!!!

 

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On 3/21/2021 at 10:57 AM, Trebor said:

Are you wondering if it will fit?  Do you think you are crossing a line that should not be crossed?  Fear not.  Now there's Screen Safe.  Screen Safe provides the boundaries you need to know, when you are pushing things beyond safe places. 

 

image.thumb.png.4ed6506e805bba7d0c86860dbe48da28.png

 

As Shown On TV, it comes completed with zoned scanline measurements!

 

Availability:
- Right here - Screen Safe (20210312).a78
- Latest 7800basic release 'samples' folder
- Coming Soon to Trebors 7800 ROM PROPack

 

As an additional bonus, to be set as the default ROM of the magnificent MiSTer 7800 core, you can obtain your very own standalone copy of a verified screen safe compliant, 7800 Non-Interactive Title Screen...

 

  

Grab your copy today...   7800 Non-Interactive Title Screen (20210320).a78 32.13 kB · 8 downloads

 

Thanks to @RevEng for both provisions! 

I would love to have that title screen in the BIOS, instead of:

PacManPlus

 

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11 hours ago, PacManPlus said:

I would love to have that title screen in the BIOS, instead of:

PacManPlus

 

Dammit Bob you beat me to this one! I've been meaning to say the same thing for the past few days. But agreed, we need a modified NTSC Bios that uses the non interactive screen during the encryption check.

 

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27 minutes ago, PacManPlus said:

Is the source code available for the BIOS?  If it is, and whomever did that non-interactive screen is willing to share their source code, I'd take a crack a trying to do that.

There's this:

https://atarihq.com/danb/files/7800bios.asm

 

Not perfect, but may have the relevant bits.

 

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1 hour ago, PacManPlus said:

Is the source code available for the BIOS?  If it is, and whomever did that non-interactive screen is willing to share their source code, I'd take a crack a trying to do that.

The main issue is it's written in 7800basic. While it compiles to assembly, it's machine-generated assembly which isn't as nice to work with. On top of that, it uses all of the flexible utility functions to draw the screen for convenience, but they make the assembly a bit more complicated than it needs to be for a bios. i.e. plotbanner commands that can move the fuji or text around. 

 

I'll have a look at unwinding it into a simpler assembly program.

 

So are we talking full encryption signature checking? Seems like a lot of stuff to port, and honestly the reason for the goofy NTSC Atari display is the check. It would be easier to just do a quick PAL style check for the cart type, display the screen a few seconds, and then launch the game. That way you could entirely avoid using Atari's signature check routines, and keep this thing open.

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Well we run into the issue where some of the people that use modified PAL bios now is so they can play PAL versions of the more expensive NTSC version games but also want that instant ON to play a game. So they might not be as interested in this. 

 

I only play NTSC stuff anyway on my 7800 in regards to 7800 games so for me the check is a non issue and I'm fine with that in place. I have my DevOS modded 7800 to check 7800 PAL stuff if needed.

 

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1 hour ago, sramirez2008 said:

That Non Interactive Title Screen is badass! 

I full agree! Can you imagine if that had existed back in the day! Hell I thought the one we had now was pretty cool in the mid/late 80s. But this just seems I don't know...it is just really cool. Might have been too modern a look for back then though?

 

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3 hours ago, RevEng said:

The main issue is it's written in 7800basic. While it compiles to assembly, it's machine-generated assembly which isn't as nice to work with. On top of that, it uses all of the flexible utility functions to draw the screen for convenience, but they make the assembly a bit more complicated than it needs to be for a bios. i.e. plotbanner commands that can move the fuji or text around. 

 

I'll have a look at unwinding it into a simpler assembly program.

 

So are we talking full encryption signature checking? Seems like a lot of stuff to port, and honestly the reason for the goofy NTSC Atari display is the check. It would be easier to just do a quick PAL style check for the cart type, display the screen a few seconds, and then launch the game. That way you could entirely avoid using Atari's signature check routines, and keep this thing open.

You know what?  That sounds like a great idea!  Start with the PAL BIOS check, display the screen for a few seconds (or maybe add a check for the PAUSE button to skip for people who don't want to wait).  Include a 'default' game when nothing is in the cart port.  I think the max was a 16K game?

 

I LIKE THIS!

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Ok, cool. I'll send the assembly version of the title your way, when I get it converted. Real life is a bit busy and I'm supporting the MiSTer core work (which isn't a lot of work, but it's time-sensitive work since it holds the devs up when I don't reply) so it may be a few days.

 

 

16K looks to be the pal bios size, so the game will have to be smaller if we're aiming for compatibility. Currently the Fuji and Atari 7800 graphic take up most of 2x 4k graphics blocks. I can skip holy DMA and put them consecutive in memory, but I think 8k for the game might be a better.

 

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23 hours ago, PacManPlus said:

[...] or maybe add a check for the PAUSE button to skip for people who don't want to wait [...]

Yeah, I like this. We could also have a compile option that inverts the behaviour - press PAUSE for title screen. My thinking is modders can stick both versions on a 32K eprom, and then use a switch to just hold the eprom A14 line high or low.

 

If someone gets sick of the title screen, flip the switch. Then if you want to occasionally use the screen to troubleshoot if a failing game is being detected at 2600, then just hold pause on power-up. (or flip the switch, but a front-of-console override is handy)

 

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  • 2 weeks later...

I just watched the developer spotlight, for the sole reason of seeing what people wrote in the chat (I couldn't see that or even the game screens during the show).  A couple of people ( @-^CrossBow^-, @sramirez2008 ) picked up on what was going on in the background. :evil: 

 

So for those of you who watched it now know what @RevEng, @Trebor, and I are working on - the Non-Interactive Title Screen as a BIOS with a small non-cart game.  A couple of things:

 

- It hasn't been released yet: although we have figured out why the ARM 2600 games wouldn't originally play, we are still working through issues with the CCII showing up with a corrupt menu about 1/2 the time.

- I will be making a small (8K), exclusive game to this BIOS for when there is no cart inserted.

- I had a third point, but I can't remember what it was....

 

BTW, Yes, that was a 3-D printed case that you saw, I am still working on the top of it (which is why it wasn't there).  I plan on calling it the '7800 Jr.' case, as it will be smaller than the original.  It will also be flat, with the front ports and switches easier to access, which should make the Atarivox fit nicer in the 2nd player port.  There will have to be a small modification to the RF shielding bottom (for people who still have theirs on) in order to make room for the screw posts. :) 

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6 minutes ago, DrVenkman said:

So a technical question for you guys: what kind of EPROM or EEPROM will I need to buy to put this new BIOS in my 7800?

 

You need more than just an EPROM (either 16K (27C128) or 32K (27C256) with a switch and a pullup resistor. But you also need a 7404 to invert the CS line and you need to swap a 0Ohm resistor (sometimes just a jumper wire).  I have a pic laying around of that section, let me dig it up.

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16 minutes ago, CPUWIZ said:

 

You need more than just an EPROM (either 16K (27C128) or 32K (27C256) with a switch and a pullup resistor. But you also need a 7404 to invert the CS line and you need to swap a 0Ohm resistor (sometimes just a jumper wire).  I have a pic laying around of that section, let me dig it up.

Didn't the original modification for the Eckard's DevOS do the same thing just attaching a wire from elsewhere on the system board to invert the signal? I know when I installed that into my original 7800, all I had to do was the jumper, eprom, and ran a wire from elsewhere. Now I want to open it back up to see exactly what I did on it since that was nearly 20 years ago?

 

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3 minutes ago, -^CrossBow^- said:

Didn't the original modification for the Eckard's DevOS do the same thing just attaching a wire from elsewhere on the system board to invert the signal? I know when I installed that into my original 7800, all I had to do was the jumper, eprom, and ran a wire from elsewhere. Now I want to open it back up to see exactly what I did on it since that was nearly 20 years ago?

 

 

Nope, the old method (Bruce Tomlin's) was piggy backing a 7404 coackroach style on top of the 7408, above the MARIA.  Unless you worked off of something else back then.  That is what I used.

 

My own method is a bit different, because I have multi BIOS modules in mine.  Here is my latest module, which will finish my ZIF monster, still need to swap the 0 Ohm and plug it in. :)

 

 

unnamed.jpg

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