Eckhard Stolberg

The important part in this code is when the STA HMOVE gets executed. At certain cycles it will not cause the usual 8 pixel black stripe on the left border of the screen. This bar actually is supposed to delay the object counters by 8 pixels and therefore allow shifting objects in both directions. (HMOVE can only shift to the left.) So without the black bar the objects don't get adjusted to the right which is why they seem to be shifting to the left. Ciao, Eckhard Stolberg

Actually you won't need a RCA-RF plug. The connector for the RF cable on the VCS is the same on all models, so you could use the RF cable from a PAL VCS. If your US VCS is a non-JR model, you'll have to open the console to unplug the cable though. Then you could try out if any of your TVs can handle NTSC colour and sound encoding. If you get proper colours but no sound, you can adjust the sound encoding inside the VCS. There is a variable inductor on the board that handles this. It looks like a little metal cube with a screw in the middle. You'll need one of those six sided screw driver things. (I don't know what they are called in English.) Ciao, Eckhard Stolberg

For the read registers the TIA only drives the topmost two bits. The lower six bits stay at whatever value the data bus currently is. Usually the last thing transferred over the data bus before the read of a zeropage register is the address of that register. So that's what the lower six bits of the collision register will usually be like on a real VCS. Ciao, Eckhard Stolberg

What's wrong with it? It used to run smoothly using the control stick or mouse, but now it can't use the mouse, and the stick just makes it jump around. That's all I know. I guess that's what you get for letting a German update an English manual. The paddle emulation through the PC joystick now takes the value from an analog axis and uses it directly as the paddle value. This is mainly to allow using Atari paddles with the Stelladaptor, but it should work with other PC joysticks as well. In the older versions paddle emulation through the PC joystick worked just like though the keyboard: pushing the joystick left or right will increase or decrease the paddle value. Due to the way reading the joysticks now works, the joystick will always override the paddle value when it is connected. So to be able to use the mouse or the keyboard to emulate the paddle, you either need to disconnect your PC joystick before you start z26, or you need to disable the input from the PC joystick with the -iJ command line switch. If you use a digital PC gamepad, playing paddle games with it currently doesn't work too well. I think I'll have to something about it in one of the next versions of z26. Ciao, Eckhard Stolberg

I'm sure Paul can come up with a much better text display himself, but if he wants to use the scrolling text demo, that one only uses about 1K for the code and the font data together. And since the displayed message is so short, it might be possible to fit everything into the 4K version of Donkey Kong if the second level gets removed. Ciao. Eckhard Stolberg

Sure, I have no problem with you (or anyone else) using these programs for personal messages. But you should really check out the original source code, because it automatically takes care of setting the proper text length information for the wrapping. Otherwise you'll either have to change the code by hand or your're stuck with using the same text length as in the demo. Ciao, Eckhard Stolberg

We considered using NASM when we chose the environment for the Windows version of z26. But we decided against it, because it required so many changes that it would have almost been a complete rewrite. Now that computers have gotten so fast (and more importantly now that I have finally gotten a faster computer myself ) it's more likely that we will rewrite routines in C code whenever something needs a bigger change. I have already done this in the newest version with the controller handling code. But since we are making bigger changes only very seldomly, it might take a really long time before this leads to a fully portable source code for z26. Ciao, Eckhard Stolberg

The text really is made of ASCII characters, so your assembler should be able to do the encoding for you. When I posted these demos to the Stella mailing list some years ago,, I included the source code too. If you really want to use it for your modification, you might want to check the list's archive for the code. That might make things like changing the text or disabling the annoying colour cycling effect a little easier. Ciao, Eckhard Stolberg

Does the PPjoy driver read the two buttons on the proline joystick independently? If so, it's normal that only one of the buttons works as the Atari fire button. I changed that from version 2.11, where all PC joystick buttons worked as the Atari joystick button. Now only PC button one does this. Buttons two and three now work as the booster grip buttons, so that you can play Omega Race with a PC joystick too. Ciao, Eckhard Stolberg

Acid Drop is programmed badly. It displays 342 scanlines per frame in the game screen. A normal PAL game is supposed to have 312 scanlines per frame. This means that Acid Drop is only displaying at about 46 Hz instead of the normal 50 Hz for PAL television. It might be possible that your TV can't sync to such a low rate anymore. BTW, which emulator did you use for testing? On some of them you need to specifically select the PAL palette to get correct colours for PAL games. Acid Drop's title screen is supposed to be blue. Your post indicates that you saw the title screen in green instead. Ciao, Eckhard Stolberg

Hello Danno, what are the specifications of the system you are running z26 on? Which command line switches do you use to start z26, and do you have a file called Z26.CLI in your ROMs directory or your z26 working directory? The smaller display is actually a feature of the SDL. If your video card doesn't support the selected video mode, the SDL will request the next higher resolution and display the picture there. This results in the smaller picture. The default video mode for z26 is 400x300 pixels in 256 colours. If your video card has problems with this, you can use the -v command line switch with z26 to select a different one. Please see the README.TXT file for a list of available video modes. The higher speed might happen, if you use the -r command line switch to sync to the refresh rate of the video mode. Since the SDL selects a different video mode for you, which usually has a higher refresh rate, the emulator will play the game at a faster speed too. If you want to use the -r switch, you should force the refresh rate for this video mode to 60 Hz. I think there is a special tool in Direct-X to do that. I have tried some of my proline joysticks, and they all work nicely with both buttons (being read as the same button by the Stelladaptor) for me. However, the 7800 joysticks use the paddle lines for the buttons too. The Stelladaptor does some autodetection for the connected controller, so it might be possible that your joystick gets detected as a paddle, when you press the buttons. Do both buttons work in z26 version 2.11 for you? Ciao, Eckhard Stolberg

Releasing Shooting Arcade in cartridge form would be difficult, because the game uses the Superchip extra RAM. Currently there is no publically available board design with a simple replacement for the Superchip. IIRC the CGExpo guys created a special board for the release of Elevator Action, but even they had to buy several hundred copies of Dig Dig and get the Superchips from there. Ciao, Eckhard Stolberg

Those of you who bought a Stelladaptor at Phillyclassic are probably eager to try out the driving controller and paddle mode with their VCS games. You now can, because I have just uploaded version 2.12 of z26 to http://www.whimsey.com/z26/z26.html. As Thomas has already mentioned, I have also added Trakball emulation through the PC mouse to this version, so that people without a Stelladapter have something new to play with as well. Note that I've also simplified the command line switches for controller selection. So please check out the README.TXT file first before complaining about something not working as it used to. Ciao, Eckhard Stolberg

USB cable: Whethere or not a USB cable will be included with the Stelladaptor is left for AtariAge to decide, but I don't expect there to be one. The Stelladaptor has a standard square B-type USB port though. So you should be able to get a suitable cable much cheaper locally anyway, if you don't have an unused one laying around already. Xbox support: If the Xbox can handle any kind of PC USB joystick, you should be able to use the Stelladaptor too by soldering a B-type USB connector to a Xbox joystick extension cable. The emulators will have to specifically support the driving controller and paddle support in the Stelladaptor though. So z26 for the Xbox will have to be updated when the Windows version of z26 with Stelladaptor support has been released. Footpedal support: IIRC the footpedal only allows you to substitute the joystick button and directional controls with one of it's three pedals. So for the Stelladaptor it's nothing more than a standard Atari one-button joystick, which is supported. If your controller hack connects anything but the paddles to the paddle input lines, it's most likely not going to work with the Stelladaptor. Stella for MacOS: Darrell, I think it might be better, if you tried to port the SDL version of the upcomming version 1.4 of the Stella emulator instead. You wouldn't have to know that much about Mac programming, since the SDL takes care of most of the hardware accesses for you. Also it might make future updates more easy, because the SDL version of stella seems to be the best supported port at the moment. Trakballs: The Stelladaptor will support the Atari Trakballs in joystick mode. It currently won't support them in Trakball mode. As far a HID controllers are concerned, mice and joystick are a different class of controller, that need a different driver in the OS. The Stelladaptor pretends to be a HID joystick, so it couldn't start sending mouse data when a Trakball is connected. It's also not very usefull to send the Trakball data as joystick data to the PC, because the Stelladaptor doesn't update it's state often enough to keep up with the speed of the signal changes in the Trakball. But even if the Stalladaptor was sending it's data fast enough to the PC, the emulator would still have to feed all that data at the right time into the emulated game. This would create a synchronisation nightmare, which would probably slow down the emulator dramatically. I don't think that would be worth the effort. But if there really is a lot of demand for a Stelladaptor with support for other controller types, and if the first version of the Stelladaptor sells really well, I'm sure Joe can be convinced to come with a clever solution for supporting them in a future revision of the Stelladaptor. Emulating Trakballs in z26 with PC mice: I have to generalize the controller handling in z26 a bit to allow support for the Stelladaptor. I guess I could add Trakball simulation during this process as well. I'm not sure if I can finish it for the next release already though. But I'll gladly get back to your offer for help, should I need it, Thomas. Ciao, Eckhard Stolberg

It's probably the the graphics chip in the console you are using. Some games position the onscreen objects in a way that the programmers manual warns about not to use, because the results might be unpredictable. The vast majority of VCSs still positions the objects in these games in a predictable way anyway, but some consoles have problems with them. I've seen incorrect positioned objects in Kool Aid Man and the Red vs. Blue prototype on one of my 2600 Jrs, but it's the first time I hear about problems with Bumper Bash. Which other games do you have that you could try out on your console to find out if it has problems with anything besides Bumper Bash as well? I don't think there is anything you can do to fix the problem, so to be able to play Bumper Bash you'll probably have to buy another VCS. Ciao, Eckhard Stolberg

You can force z26 to save the screenshots in BMP format with the -B command line option, if this is any help. In this mode it will also save the screenshots with the colour depth of the video mode you chose instead of the fixed 8bpp in PCX mode. That way you can also make screenshots of things like Andrew's picture demos with z26's phosphor effect to combine all frames that make up the picture. Ciao, Eckhard Stolberg

Activision used this sticker on some of their PAL games that were sold in France to indicate that the game would work on the SECAM VCSs too. You can sometimes find games like this on ebay.fr . The games themselves are the regular PAL version though. I think Activision didn't even bother to check the B/W switch so that they could adapt the colours to SECAM, like Atari did with most of their games in the early 1980s. I think Activision used a similar sticker with a 'N' instead of the 'S' on the games that they sold in Canada with the "International Edition" label. Ciao, Eckhard Stolberg

The binary for Pitfall II contains 8K of code, 2K of graphics data and 255 bytes from the pseudo random number generator. Therefore the 10495 bytes binary is the correct one. I don't know where the extra byte in the longer binnary comes from. But since emulators are recognizing games by file size and checksum, the binary can't be detected properly and therefore would be playing with the wrong bankswitching format. Ciao, Eckhard Stolberg

I'm not saying anything about the quality of the 7800 progamming documentation, but you probably have a complete copy. There is no hardware collision detection in MARIA mode. You have to take care of that in software. Ciao, Eckhard Stolberg

Without having a closer look at the Schematics: Aren't the CX-80 Trak-Balls like this? There are some CX-80s that are still compatible with the CX-22, some have some modification done to them that make them compatible with the ST mouse, and some are compatible with the ST mouse without any modification. So, could it be that the design for the 7800 Trak-Ball later was used for the ST mouse? That would explain why Atari build a second 2600-compatible Trak-Ball without having any games making use of either design. Ciao, Eckhard Stolberg

PCAE, Stella and z26 all emulate both joysticks with the PC keyboard. You should have a look in the manual to find out which keys are used in your favourite emulator. IIRC Stella uses either O J K ; or I J K L for the second joystick and the big ENTER key for the second button. Ciao, Eckhard Stolberg

The GBA version of the Activision Anthology hasn't been released over here, so maybe you could describe how the controls for Kaboom work. Does it make use of the analog nature of the buttons (pushing harder makes the paddle move faster), or is it just "push left to move the paddle left"? If it's the later, we already have something like this in z26. We use the cursor keys or the directional control on a PC joystick for this though, so it might not feel quite as nice for you. About the mouse-as-paddle emulation: John and I don't like it too much either. This is why we both use a trak-ball on our PCs instead. OK, you have individual files for each load, which are 8448 bytes big and have an .a26 extension, right? Then you have to open a command line prompt in the directory with these files and type something like this: copy /b LOAD1.A26+LOAD2.A26+LOAD3.A26 GAMENAME.BIN This should result in a file named GAMENAME.BIN which has all the loads for the game in it. You can use this binary with PCAE, Stella or z26 just like any other 2600 game. Ciao, Eckhard Stolberg

Hello Karolj, sorry, but I don't have much time to experiment with your code at the moment. But the A78 header contains some information about the ROM size (the four bytes after the game name), so if you are making the ROM bigger, you have to adjust that value too. I don't know much about 78hdr, but I'd expect it to set this value properly though. Also you need to generate a new signature key with A78SIGN, if you want to use the binary with the NTSC version of the 7800 BIOS. Ciao, Eckhard Stolberg

So you got it working now, right? Some other things you need to keep in mind: The 7800 only has one POKEY, so you can only play songs with a maximum of 4 channels. Most RMT demo songs seem to use 8 channels. The 7800 player routine was converted from the player that came with RMT 1.12 (I think). Since then Raster made some changes in the player routine. So songs that use the new features of RMT 1.14 won't play properly on the 7800 either, unless the 7800 player routine was updated as well. Ciao, Eckhard Stolberg

If you had said, that the commecial emulator packages have a much nicer user interface than z26, I would have wholeheartedly agreed. I have to admit, that we are seriously lacking in this department. But the comment about the emulation quality surprises me. I'd be interested to hear which games you think the Activision Anthology emulates better than z26. Or at least tell me which games play so badly on z26 that you prefer the GBA version over it with all the compromises that had to be made on this system. Having our PC program outperformed by a GBA is such a shame that I probably can't sleep until the problem is fixed. Ciao, Eckhard Stolberg