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doctorclu

Member Since 28 Jan 2004
OFFLINE Last Active Yesterday, 12:06 AM

Topics I've Started

Understand Missile Objects

Fri Apr 13, 2018 9:40 AM

So I'm currently testing games on a Atari 2600 emulator on the Atari Jaguar and I believe I have narrowed one of the problems it currently has is the display of the missile objects which I believe is M0 and M1?   There are quite a games where the missiles are not displaying like on Space Chase, Beat em and Eat em, Astro Swarm, Space Raid, and so forth. 

 

However, the missiles can be seen on Gorf and Astroblast.

 

 So I was curious how the missiles in these two categories of games differed.  Why does one work and other does not?

 

Also trying to figure out the disassembly screen in Stella.  I see where you can have images displayed on frames that you can step through.  How do you pinpoint the missile object and trace it's actions back to what defines it, such as color of the missile object?

 

 

 

 

 


Atari 2600 roms that were all text?

Sun Apr 8, 2018 8:11 AM

I'm wondering if there were any Atari 2600 roms that were nothing but pages of text?

 

Why would a person want this?   To tell an intro story, or maybe to have an instruction manual in a rom library.

 

Just text, which a person "turns the page" by hitting the fire button or something similar.

 


Does Pitfall contain a VCS emulator?

Fri Mar 30, 2018 2:55 AM

Does Pitfall: The Mayan Adventure contain a VCS/2600 Emulator to run the Atari 2600 version of Pitfall?

 

I don't think so.   I would like to be wrong.

 

Over the years Activision has managed to port Pitfall fairly faithfully from the Atari 2600, Atari computers, Intellivision, all while looking about the same.  They took a slight divergence with the ColecoVision, but all this to say Activision has had the ability to port their games and keep the same look and feel.  So to me it was not surprising that they could do it yet again with the Atari Jaguar.

 

And that's all fine and good, but what I am bringing to this age old debate/mystery?   Since this is practically hexediting/emulation month for me (sprite hacking in past months) I thought I would look for the hex values of the original 2600 Pitfall.

 

Attached File  Screen Shot 2018-03-30 at 3.30.49 AM.png   21.61KB   11 downloads

 

Now previously I had said on the VirtualVCS thread that I looked for these values in the Jaguar Pitfall image and did not find them.  Then I realized that the Jaguar cartridge image was in a compressed format. 

 

At one time I was guided to use a program called Multi Ripper or "mrip260.zip" as it can be found on the internet for unpacking a compression format that Imagitec tends to use from the Rob Nothern Computing or RNC for short.   The multiripper can look for these files and it spits out... a bunch a files with the .RNC extension.   This worked really well in breaking down Bubsy: Fractured Furry Tales into graphics, map, music, and other files, though I had to pull (with help) the file directory to rename most of those files.  Still have some to identify or file, but found like 90% that way.

 

So I did the same to Pitfall tonight and looked for the opening "78D8 A200" characters of 2600 Pitfall throughout all the RNC files that Jag Pitfall spit out annnnddd... no match.

 

Attached File  Screen Shot 2018-03-30 at 3.30.05 AM.png   36.9KB   9 downloads

 

But this might not be the end.  As you can see in the picture above there is the RNC in the text portion, leading me to wonder if this needs to be further unpacked?

 

But tonight I took it through at least one level of compression and found nothing so far.

 

(File contains the unpacked files I looked through if others want to do more digging and comparison.)


All in one stop for 2600 game images?

Thu Mar 29, 2018 12:29 AM

Is there a definitive download link of all Atari 2600 roms that are available, official releases and home brews?


Need help hacking Return of Heracles

Mon Mar 26, 2018 9:53 AM

So the Return of Heracles is a game that is mostly joystick driven except for one part of the game where you are stopped by the Sphinx for the "riddle of the ages" which is:

 

"What walks on four legs in the morning, two in the afternoon, and three legs in the evening?"

 

To which you type on the keyboard "man".

 

Currently trying to get this game working on a system without a keyboard so typing that would be a stopping point in the game.  Is there any way to hack a way past that?

 

Return of Heracles attached below if someone would like to take a crack at it.

 

 

Why?

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Been playing with prototype emulators, one if the Atari 2600 emulator for the Atari Jaguar, and using what I learned there, I am thinking of trying the same trick on the Atari 800 emulator for the Nuon.