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DanBoris

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Posts posted by DanBoris

  1. Posted

    You can run some 2K and 4K rom images on an un-modified Supercharger. There is a program by Bob Colbert called Makewav that converts the .bin files to .wav files that Supercharger can load.

     

    The reason the modification is needed for some games is that the Supercharges uses a series of memory locations to control it's bankswitching and RAM etc. So if a game tries to use these addresses it will crash.

     

    You can get more info here: http://members.home.com/rcolbert1/super.htm

     

    Dan

  2. Posted

    This gets a lot more complicated then the 2K and 4K carts. The 2600 can only directly address 4K of cartridge ROM, so to access the bigger ROMS you have to do bankswitching.

     

    To make a copy of a 8K or larger cart you will first have to determine the bank swithcing scheme it uses (there is a document floating around by Kevin Horton which explains all the schemes). Next you will have to build a logic circuit that simulates that bankswitching and controlls the upper address lines that don't come directly from the system.

     

    As to the problem of the ROMS having more pins, one way to work around this is to solder a socket of the size of the EPROM into the spot on the cart PCB and let it hang over to the pin 1 side of the EPROM. Most of the pins that match up will have the same function so you will only have to rewire the overhanging pins.

     

    Hope this helps

     

    Dan

  3. Posted

    The 20 year figure is also just an estimate. I have seen engineering documents say that EPROMS could last up to 100 years. Also, we are gauging bit rot based on old EPROMS, it's quite possible that newer EPROMS will take even longer to suffer bit-rot.

     

    Dan

  5. Posted

    quote:
    Originally posted by Jet Boot Jack:

    Bill - the Shamus sprites move at 1 pixel increments not 4! The data is rotated thru the characters - that's the way I've done it in the past - with either 10 characters each at different data offsets or copying the data into a block of 6 characters or so you can get 100% smooth motion!!

     

    sTeVE

     

    It appears that in Shamus a sprite has to be fully within a character cell before it can change direction. With this restriction in place it will only take a max of 2 character cells to hold a 4x8 sprite. Without this restriction a 4x8 sprite could potentially appear in 4 characters cells at once.

     

    Dan

  7. Posted

    <BLOCKQUOTE><font size="1" face="Verdana, Arial, Helvetica">quote:</font><HR>Originally posted by Cafeman:

    <STRONG>Dan, I am using VSS .80. Do I need to download a different 'version' of VSS for the debug feature? I will check it out.

    </STRONG><HR></BLOCKQUOTE>

     

    Moderator Edit: The 'debug' version of VSS .80 is located here: http://atarihq.com/danb/

     

    <BLOCKQUOTE><font size="1" face="Verdana, Arial, Helvetica">quote:</font><HR>[QB]

    Also, Popeye doesn't run in VSs .80 for me - the screen is black but I hear the music. Popeye doesn't run in Atari800win for me either -- it crashes.

     

    QB]<HR></BLOCKQUOTE>

     

    Maybe you have a bad ROM image for Popeye. I do recal at one time there were some bad images floating around.

     

    Dan

  9. Posted

    If you look at the display list of Joust you will find one DLI at the start, then 2 towards the end. I assume from this that after that first DLI the game simply stays in the DLI for the entire height of the screen, making the sprite position moves as needed. Doing this will each up a lot of processing time, but this wouldn't be a problem with a game like Joust since it has fairly simple game logic and doesn't need the time to do other stuff.

     

    If you didn't want to do it this way, you could dynamically alter the display list for each frame and insert DLI's only in the places where you needed them.

     

    You can easily determine where different players and missiles are used by using my VSS emulator (www.atarihq.com/danb). The debug version has the ability to turn each player and missile off by pressing keys on the keyboard.

     

    Dan

  11. Posted

    Yes, in theory they should work with any system that has a ROM. I have used it with the 7800 and the Odyssey 2, work great on both. The only trick can be building a socketed cartridge to plug the emulator into. For example the eprom emulator I use has a 28 pin connector on it, but O2 carts only take 24 pin EPROMS, so I had to so a little re-wiring to get it to work.

     

    Dan

  14. Posted

    quote:
    Originally posted by Cafeman:

    Second thing -- An Eprom Emulator. Hmmm, so it would plug into my 5200 cart that I plug the eprom into? And I'd have to have the PC running side-by-side with the 5200 on a tv set? And there is no slowdown of access via RAM, as opposed to right off an Eprom?

     

    Not quite, you plug the EPROM emulator into the 5200 cart and into the PC. No actual EPROM is needed. The emulator hooks to your PC parallel port so you can put an extension cable on it so your PC doesn't have to be right next to your 5200. There is no slow down, the 5200 see it as if it was an EPROM. The beauty of this is that you don't have to burn a real EPROM until your game is complete. If it works with the emualtor it will work exactly the same when you finally burn it to an EPROM.

     

    Dan

  15. Posted

    First I would try cleaning the cartridges and the cartridge slot. These can be cleaned with alcohol and qtips. To get into the cartridge slot I usually wrap a tissue around a small flat blade screw driver and wet that with alchohol.

     

    If this doesn't work, the next thing to try is to disassemble the 2600 until you get down to the circuit board. On the 6-switch you want to get all the way down to the circuit board under the metal can, the one the cart plugs into. Once you get to the board put it on a flat surface and push down on each chip on the board to make sure they are firmly seated in thier sockets. If you are up to it you may want to remove and re-insert each chip, but you have to be careful doing this.

     

    The final step if none of this works is to touch up the solder joints. You will need a soldering iron and solder to do this. Pay particular attention to the solder joints on the power connector, and switches.

     

    I find that 95% of the time these steps will get the system working again.

     

    Dan

  16. Posted

    First I would try cleaning the cartridges and the cartridge slot. These can be cleaned with alcohol and qtips. To get into the cartridge slot I usually wrap a tissue around a small flat blade screw driver and wet that with alchohol.

     

    If this doesn't work, the next thing to try is to disassemble the 2600 until you get down to the circuit board. On the 6-switch you want to get all the way down to the circuit board under the metal can, the one the cart plugs into. Once you get to the board put it on a flat surface and push down on each chip on the board to make sure they are firmly seated in thier sockets. If you are up to it you may want to remove and re-insert each chip, but you have to be careful doing this.

     

    The final step if none of this works is to touch up the solder joints. You will need a soldering iron and solder to do this. Pay particular attention to the solder joints on the power connector, and switches.

     

    I find that 95% of the time these steps will get the system working again.

     

    Dan

  17. Posted

    <BLOCKQUOTE><font size="1" face="Verdana, Arial, Helvetica">quote:</font><HR>Originally posted by Cafeman:

    <STRONG>So I will need to adjust the colors, and it will be difficult and I'll need to right and re-write Eproms because I just can't tell from the PC what the end result is going to look like.

    </STRONG><HR></BLOCKQUOTE>

     

    You might want to invest in an EPROM emulator. This is device that plugs into your PC, and into the socket where you would put the EPROM and simulates the EPROM via RAM. You run a program on your PC to download the code to the emulator and the system sees it just like an EPROM.

     

    I have one from a company called Souther Cross, you can see it here:

     

    Moderator Edit: Search for it on http://www.wiltronics.com.au

     

    I used it quite extensivly when I was reverse engineering the Odyssey 2. It works great and is reasonably priced.

  18. Posted

    <BLOCKQUOTE><font size="1" face="Verdana, Arial, Helvetica">quote:</font><HR>Originally posted by Cafeman:

    <STRONG> I tried using the trak-ball but it wouldn't move koffi at all. I thought the machine reads the trak-ball signal just like the analog sticks but there is obviously more to it than that.

    </STRONG><HR></BLOCKQUOTE>

     

    The 5200 does read the track ball just like an analog stick. The speed you rotate the ball is equivelant to how far you push the stick in a specific direction. So rolling the ball slowly to the left is like pushing the stick slightly to the left. Rlling the ball quickly to the left is like pushing the stick hard to the left.

     

    The reason is probably doesn't work with Koffi is that I assume you are checking for the stick value to go above or below a certain value to read each direction. The track ball may never get over these limits, or it might have to be rolled very fast to reach them.

     

    A game like Koffi that simulates a digital stick from the analog stick won't work with the trackball. But a game that actually reads the stick as analog (Centipede for example) will work with the trackball.

     

    For anyone who is interested the schematic for the trackball is on my web page.

     

    Moderator Edit: Dans Page is located here: http://atarihq.com/danb

  19. Posted

    quote:
    Originally posted by Greg @ TAT:

    Now that I've tried it, I'm sorry to say that I'm not all that impressed. About the only thing it has going for it is 7800 emulation. Other system specific emulators do a better job... And I'm surprised 2600 emulation is not 100%.

     

    The MESS engine is not really well suited to emulating the 2600 hardware so it is taking a lot of work to get it emulated in MESS.

     

    quote:

    It will take several more releases before this one can compete with the more established emulators.

     

    Well, we aren't actually trying to compete.

     

    Dan

  21. Posted

    There have been several attempts to come up with a "correct" color pallete for the 5200/8-bit but it seems that no one has actually succedded. One of the problems is that color is quite subjective, some people are more sensitive to differences in color then others. Also when a color is found to be wrong, how do you explain what it should look like. And Finally, different combinations of systems and displays (TVs) will give different colors again making it hard to get the colors just right.

     

    Porting a game like this to the 8-bit should be quite easy especially since the author has the original source code. It would just be a matter of changing some memory addresses and altering how the sticks are read. There was actually someone "back in the day" that hacked a number of 5200 ROM images to be playable on the computer and managed to do it without original source code.

     

    Dan

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