Eckhard Stolberg
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Posts posted by Eckhard Stolberg
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Your Karateka prototype looks as if the EPROMs are socketed. This game is 48K big, so one of the chips should be 32K and the other one 16K. I think the one labeled HI is the 32K chip and is also mapped in at the correct address range. You could try to carefully lever this chip out with a flat screwdriver, making sure that you don't bend any of the pins. Then you could put in your new EPROMs into the socket. (The notch must point into the same direction as it is on the chip currently in the socket.) This would allow you to try out the EPROMs on a real 7800 console.
Ciao, Eckhard Stolberg
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Christian,
Randy Criehfield from Hozervideo also does 8K and 16K games, so he must know how to do the modifications. But I think he uses newly made boards from Chris Wilkson, because putting all the extra chips on a normal Atari cart was too difficult. You probably can ask either of them for more information. They are really nice people who are willing to help others with their information.
And yes, I did see your message. I was just hoping that you would send me your new SECAM information in a detailed email.
BTW, if you or anyone else could help me find a cheap SECAM VCS, so that I can do some tests myself, I would really appreciate that.
Ciao, Eckhard Stolberg
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No, the unroller controller is nothing more than a normal joystick that has a bowl for the control instead of a stick. They might be alright for some of the 8-bit applications that supported joystick input to move a 'mouse pointer', but for games they are pretty uncomfortable.
And as a serious word of warning, whatever you do never try to use the unroller controllers for a competetive game of Decathlon. I think the pair that a friend of mine won from a magazine still has the bloodstains on them from the one time when he thought that it would be a good idea not to use his good joysticks for this game anymore.
Ciao, Eckhard Stolberg
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quote:
Originally posted by khryssun:I've questions about the backswitching support for games above 4k.I read somewhere that 8k carts and above need an extra chip for bankswitching.But a guy tells me there isn't extra chip in the asteroids cartridge (8k)... it's an obscur point for me.How it works ?
The VCS can only address 4K of game ROM. For anything above that you'd need some special circuit that toggles the highest address line when a certain memory address is accessed for example. Since the ROM chips in the VCS games are specifically made for a certain game, it's no problem to add these logic functions to the chip as well. But if you want to create a bankswitching game from a standard EPROM chip, you need to recreate the bankswitching logic with some standard logic chips too.
As for finding a cheap EPROM burner, have you tried some auction sites like ebay? Sometimes older EPROM burners that can only do smaller EPROM types can be found at a reasonable price there. And since VCS games are very small anyway, these EPROM burners might be ideal for your purpose.
Ciao, Eckhard Stolberg
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Is this on a PAL or a SECAM system? On a PAL system this is normal behaviour for this cart. Due to the way how colours are encoded in the PAL VCS a game will not display any colours, if it does an odd number of scanlines per frame. Unfortunately most non-Atari games on the 32-in-1 cart seem to be NTSC versions that were badly hacked to meet the PAL specifications in the VCS programmers guide without actually having been tested on a real PAL VCS. Other NTSC games like Combat also don't show colours when played on a PAL VCS. The boxing game in the 32-in-1 cartridge even switches between colour and no colour depending on the boxer's positions. Z26 simulates this behaviour with the -o command line switch.
If you have the 32-in-1 ROM image split up into individual 2K files, you can try it out yourself. Do we need to add this effect to the SECAM emulation too now?
Ciao, Eckhard Stolberg
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Originally posted by liquid_sky:while we are on the topic of z26 is it just me or does it also make strange sounds like when you use a digital phone on pulse dialing mode?
Normally it shouldn't do that. It sounds more like a problem with the soundcard configuration or the Soundblaster DOS mode driver. I think John occasionally gets complains from people who use soundcards that are not Soundblaster compatible through hardware but through an SB emulator, like the SB live. How do other DOS based programs work for you? PCAE for DOS also mentions problems with the SB live card in it's documentation for example.
Ciao, Eckhard Stolberg
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I'm from Germany too, and I got my 2600 jr. for Christmas of 1984. It came with two proline joysticks and Centipede as the pack-in game. It's manual has a copyright date of 1983. A friend of mine who got his VCS a couple of month before me still got a woodgrain model with Pac Man, though.
Ciao, Eckhard Stolberg
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Originally posted by -^Cro§Bow^-:z26 does hose up the screenshots...no doubt...but there is a way to do it.
The screenshot feature in z26 was created before the support for the tall video modes was added and hasn't been updated since. Therefore the screenshot feature will only work properly in the smaller video modes like modes 0-3, I think. Since the tall video modes are used by default, you have to switch to one of the smaller modes with ALT-0 for example, if you would like to do screnshots. You might also have to center the screen again with the PAGE UP and PAGE DOWN keys.
As for doing encoded screenshots in z26, I don't think it would work. The source code is openly available, so everyone could disable the security checks and still use every possible cheat to play the game.
Ciao, Eckhard Stolberg
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Originally posted by -^Cro§Bow^-:2. Since I have Eckhard's DevOS installed and have modified my 7800 to use Joystick port 2 for interfacing to the PC. Can I still use the keyboard on this 7800? The modded 7800 does still have joystick port 2 for a second player works just fine.
There is no modification done to the joystick ports. They should just work as normal. I must admit that in DevOS 0.1 I didn't reset the direction on joystick port 2 after a transfer. So if you want to use a game on the RAM cart that uses both joystick ports but doesn't reset them at startup, the second joystick wouldn't work properly. But playing games from carts without doing any transfer first shouldn't cause any problems.
Ciao, Eckhard Stolberg
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My PAL version of Ballblazer for the 7800 has a red end label too. FWIW, I traded it from a guy in Australia.
Ciao, Eckhard Stolberg
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Your board is just like the normal Ballblazer board. It will only play normal production ROMs. To be able to use EPROMs with your board you still have to add the inverter chip. If you look at the picture of the board, you can see a big chip with a "proto 88" sticker on it. This is the POKEY chip. To the right of this chip you can see two rows of solder spots going down. This is where the inverter chip has to be soldered in. Under those two rows, right before the edge of the board, there are two other solder spots connected with a little piece of wire. It's a bit hard to make out on the picture. You have to remove this wire to enable the inverter chip. Now your board should work with EPROMs but not with normal production ROMs anymore.
Ciao, Eckhard Stolberg
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To Tempest:
All the EPROMs on the picture have 28 pins, which means that they can contain 8K, 16K or 32K of data. There is no need to make any changes to the board because of this. The EPROMs probably all are 32K anyway.
There is no difference between the two boards itself. The other one only already has installed a second ZIF socket and a switch. You can do that to your board to (or to any other Ballblazer board, if you don't want to mess around with your expensive purchase). The difference between a 32K EPROM and a 32K Atari game ROM is only that the chip enable line has to be inverted. Where the second board has the smaller ZIF socket you can install a 74LS04 inverter chip. Where this board has the switch there is a wire jumper on your board. If this jumper is closed, the chip enable line will be fed directly into the (EP)ROM chip, and if the jumper is open, the chip enable line will be taken through the inverter chip first. The other board uses the switch so that it can play EPROMs as well as normal ROMs.
You are right about the POKEY chip. It shouldn't be a problem for any games up to 32K.
To Alex:
If you want to know if two binaries are the same, you can just use the DOS file compare command. At the DOS prompt type "fc /b file1.bin file2.bin" and it should tell you where the differences are.
Ciao, Eckhard Stolberg
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quote:
Originally posted by Tempest:I'll let everyone know what I find out. Do you think they'll work without modification?
The board you won should only work with the original Ballblazer ROM, not with any of the EPROMs. (OK, other 32K ROMs like Ms. Pac Man should work too.) The second board should support 32K EPROMs, if you'd put an inverter chip into the second ZIF socket and flipped the switch. Atari apparently designed the Ballblazer POKEY board to work as a prototype or loaner board too. They specifically left a space for the inverter chip on the board and added some wire jumpers that let you chose between a game on a ROM, an EPROM or an EEPROM (all with 32K).
These board probably are real, but you could get the same thing done with a normal Ballblazer cart, that Oshea still sells for $2. So I hope that you'll get a hundred dollar's worth out of the included EPROMs.
Ciao, Eckhard Stolberg
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About the emulator speed on the PSX:
There are two major differences between arcade emulation and VCS emulation. The first is that arcade games have a more advanced graphics hardware than the VCS. If the game only sets up a couple of sprite and background pointers once per frame and then lets the graphics hardware do the rest of the work, you can write an optimized routine to handle this. And since this routine would only have to be called once per frame, you don't need too much processing power for the emulator. But the VCS only has enough video memory for one scanline. So the game has to change the graphics data in every line to get to display anything. Most games even change the graphics data in the middle of a scanline to get better looking displays. This means that the handling routine for the graphics processor has to be called a lot more for a VCS emulator. Also you have to check if any access to the TIA would cause some of the special graphics tricks to happen that are beyond the original TIA specifications. Examples for that would be the Cosmic Ark starfield effect or the extra tanks display in Robot Tank.
The second difference is that arcade emulators only need to work with one game, while a VCS emulator has to work with many games. If you know the game you want to emulate, you can customize your emulator to it for better results. For example in Kaboom the biggest part of the screen is only filled with the bombs and the paddles. The bombs are one sprite that gets repositioned during the screen and the paddles are another sprite. If you only wanted to emulate Kaboom, you could write the emulator in such a way that it wouldn't render any other objects besides these two sprites and wouldn't have to check for collisions with any other objects either. Then this emulator could probably run at full speed on the PSX.
But if you wanted to release an emulator package with 30-50 games, it might not be worth spending so much development time with essentially rewriting your emulator for each game.
The PS2 on the other hand is running at about 300MHz, right? I think this should be enough to handle an universal VCS emulator at the full frame rate.
Ciao, Eckhard Stolberg
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It seems that Tempest has won this auction. And judgeing from how much he seems to like posting in this forum, we might find out if the EPROMs contain any prototype games in a couple of days.
Ciao, Eckhard Stolberg
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I don't know what you guys have against a PC version. If it included all the Activision, Imagic and Absolute games plus some prototypes, that aren't available on the net yet, plus some multimedia stuff, I for one would like to see such a package come out on the PC.
As for the PSX, this console is just not fast enough to do a proper universal VCS emulator. You'd have to use hand optimized assembles code and still would need to do some customizing (i.e. disabling unnessessary calculations on a gamescreen by gamescreen basis) to get get the games to play faithfully on the PSX. Even the old emulator wasn't THAT bad. It could do full frame rate and collision detection in every scanline on a fast enough machine. On the first PC versions you could even adjust this in the INI files. The documentation didn't mention that though, and the sound really was pretty unacurate.
And for Ken:
You might want ot contact Glenn Saunders from the Cyberpunks. Their address can be found on the links page of this site. Glenn has done a very nice video documentation on the VCS and still has plenty of interview footage left over. Also he tried to get Hasbro into releasing a VCS emulator package. This never happened, but for this project he had Bradford Mott brush up his Stella emulator to a fancyer product. So you probably could get everything you need easily from the Cyberpunks. And Brad's emulator is written entirely in C++, so porting it to one of the faster consoles might not be much of a problem either. You can already check out the quality of this emulator by downloading one of the older version from the emulation page of this site.
Ciao, Eckhard Stolberg
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This is just a normal Ballblazer board with a chip socket installed. The chip under the "proto 88" sticker is the POKEY. And while the numbers are a bit hard to make out, I think that the ROM in the top right corner is the normal Ballblazer ROM. It should work in this board.
About the EPROMs: nowhere in the auction description does it say that the EPROMs would work in this board or that they even do contain any data. You could make the board work with EPROMs by installing an inverter chip and a capacitor into the free spot to right of the POKEY and opening the wire jumper below this spot, though. You could even make it work with EEPROMs by changing the two wire jumpers below the two resistors.
It still might be a genuine Atari loaner cart that was send out to magazines for reviewing the final version of the game while the carts still were in production, though. But before you bid on the EPROMs you might want to ask the seller about their content first.
Ciao, Eckhard Stolberg
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quote:
Originally posted by Robert:What about playing NTSC games on on PAL 7800. Is that possible?
That depends on a game to game basis. The main differences between the NTSC and the PAL 7800 are that the the PAL 7800 does more scanlines per frame, which results in a lower framerate, and that the colour palette is shifted a bit. So even if you can get a game to work, it would still run slower than intended and the colours might be off a little. Also depending on your TV the topmost part of the game display might be in the invisible part of the TV screen.
And since the console tries to display more lines than the game has set up, some other data would be interpreted as display information. If you are lucky, this would just cause some garbage on the lower part of the screen. But on some games this data might for example cause an interrupt, when the game has no proper interrupt routine set up, or something similar. In these cases the game will not work at all on the PAL 7800.
So all in all, trying 7800 games for one TV standard on a 7800 console with a different TV standard is not something to be recomended.
Ciao, Eckhard Stolberg
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I have that game too, but mine is called Time Race. It comes in a Funvision type case and uses the same picture that you can see some posts above. It says Goliath on hte screen though.
Ciao, Eckhard Stolberg
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Speaking of Frogger, I have another strange variation, that isn't on Marco's picture. The game comes in a black Homevision style case, and the label looks like what the offical Parker label would have looked like on a case like this. It even has the 'Weltbekannt duch Monopoly' logo printed on the label, that some German Parker games have as an extra sticker on the normal label. Has anyone else seen this variation, and are there other Parker games in this case?
BTW, the gatefold Parker boxes with the cut off top left corner also have the 'Weltbekannt durch Monopoly' logo on them. Were these made specifically for Parker Germany, or were they available elsewhere in the world too?
Thanks, Eckhard Stolberg
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For Joel:
The problem with the pirated games is that different distributors used the same name or the same picture for different games, as Jahfish has just pointed out. Therefore you'd probably have to describe the gameplay a bit in order to allow us to identify your game.
For Tempest:
I believe that most of the pirated carts were made by Suntek. I opened some of my carts with different cases and labels, and most of them said SUNTEK or SAE on the board. And since a good deal of the carts also has S.S. on the back, I consider that as a sign that these games were made by Suntek too.
Games that have the same kind of case and label as the Zellers carts were sold by other companies around the world, for example by Quelle in Germany. The only reason to keep the Zellers games seperately would be that the Zellers carts are probably NTSC versions, while most of the other games are either PAL versions or NTSC versions patched to work on PAL.
Ciao, Eckhard Stolberg
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Marco,
sentiments like yours were one of the reasons why we chose to use a 7800 console as the basis for our cart reader. The transfer routine can't do anything to your games, that a normal 7800 couldn't do either.
And the communication with the PC happens over the joystick port, pretty much like with the keyboard controllers or the Compumate. So, if you have no problem playing your prototypes on the 7800, then there shouldn't be a reason why you wouldn't want to use this console to read out the ROM data. And if you really are that clumsy, it's probably better to make some backup copies of your valuable carts for playing and store the originals in a safe place, where you can't reach them.
Ciao, Eckhard Stolberg
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It might or might not be a compatibility test, depending on what version of Robot Tank you have. I believe that Activision changed the three games with the problematical bankswitching method (Decathlon, Robot Tank and Space Shuttle) after the release of the incompatible 7800 consoles. For example my PAL picture label version of Space Shuttle uses Activision's FE bankswitching method, while the ROM on the net uses Atari's F8 bankswitching method. And while my PAL picture label version of Decathlon also uses FE bankswitching, I have a HES rerelease version, that uses Atari's 16K F6 bankswitching. So I think the picture label version of these three games might have trouble with the later models of the 7800, while the text label versions and the HES rereleases might work on any 7800 console.
Ciao, Eckhard Stolberg
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Thanks for figuring out the true SECAM colours. I was just guessing the values from the description in the VCS programmers guide. I have changed the code to use your palette now and sent it to John. It might take him a while to release a new version though. BTW, if you have any of the misterious SECAM only games by Activision or CBS and would like z26 to recognize the ROMs automatically, please let me know.
Thanks, Eckhard Stolberg
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Those Funny Ebay Prototypes...
in Atari 2600
Posted
No, the 16K chip contains additional data for Karateka. But if the games on your new EPROMs are only 32K big, they wouldn't expect any data at the address range where the 16K chip is mapped in, and therefore not access it. So there should be no problem if you just leave it in. If the EPROMs contain different versions of Ballblazer, they would try to access the POKEY chip at this address range though. But that shouldn't be a problem either, except that you wouldn't get any sound of course.
Ciao, Eckhard Stolberg