DanBoris

You can probably get the XEGS schematics here: Best Electronics For the differences between the 5200 and the computers check out this article on my web site from Analog magazine, it does a pretty good job describing the differences. Analog 5200 article Dan

There is a USENET posting from 1998 that talks a little about who Glenn was. Don't know if it's true, but don't see any reason it wouldn't be: Google Groups Dan

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

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

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

<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.

<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

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

... and MESS contains the only Entex Adventurevision emualtor! Dan

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

Both buttons can be read from INPT4 ($0C) and INPT5 ($0D) on the TIA. You can read the buttons individually via the paddle inputs on the TIA $08-$0B, two ports for each stick, one for each button. Dan

Good news, the bug that broke a lot of the games has been found so we won't have this problem in the next release. Dan

No a color clock does not necessarily equal 2 pixels. You need one full color clock per pixel to have a pixel that can have a full range of colors. In Antic 2 and Antic F there are 2 pixels per color clock, but they loose ability to represent a full range of colors. Dan

You can get them from Best Electronics: http://www.best-electronics-ca.com/ The 7800 adapter is tricky to get most places because of the unusual connector. Dan

Yes, MESS can be a pain to get working (this coming from one of the developers!) But once you get it going it's not to bad to use. If you want to try the 7800 emulation be sure to use the previous version of MESS, a bunch of games that used to work don't work in the new version. Dan

I have frequented #rgvc for over 4 years now, used to spend A LOT of time there, but I don't much anymore. It's a good channel with some good people, but it's not quite a busy now as it used to be. I do recommend people check it out if they get a chance. Dan

Players at normal resolution are 8 pixels and 8 color clocks wide. To get 16 controllable pixels you will have to use to PM's as far as I know. Mode E is 1 color clock per pixel. The screen has 176 visible color clock, 8 on each side for a border leaves the mode E resolution of 160. Move F achieves 320 pixel resolution by making each pixel 1/2 a color clock, that's why you get color artifacting in that mode. Dan

quote: Originally posted by Albert: Thanks for the tip, Mitch! Now I need to fire it up and take some screenshots for those games (finally!) I was beginning to wonder if they'd ever release a new version. I looked at the release notes and they didn't even mention any Atari 7800 changes! So what other 7800 games aren't properly emulated? All the Absolute titles? Any others? ..Al The bug fix that enabled those games to work was very minor and submitted months ago, so that's why it probably didn't make the list of changes. Yeah, the Absolutes still don't work not sure why. Also Double Dragon and I belive Rampage don't work because of thier strange bankswitching that I still need to implement. Last time I check Tower Toppler ran, but the graphics where incorrect. Dan

The build it TIA sound chip gives 2 voices, and a POKEY chip could be added to carts which gave an additional 4 voices. quote: Originally posted by -^Cro§Bow^-: Don't forget that while the 7800 could handle lots of sprites...it is also still a scanline renderer like the 2600. It is a scanline renderer, BUT unlike the 2600 the graphics hardware does all the work, not the processor. There is no solid answer to how many sprites the 7800 can handle. Put simply, for each scanline on the screen that graphics chip reads a list of "objects" that appear on that line and copies thier graphics data from memory to a scanline buffer, which will be displayed on the next scanline. So the graphics chip has the duration of one scanline to copy data from memory to the buffer, that's the only real limitation on how many objects (sprites) can appear on each line. Dan

Since Atari's problem was never really with the technology, but with marketing, mis-management, etc., they probably would have killed the NES. I doubt the NES would have become as succesful as it did if Atari had, had it's hands in it. Dan

Unlike the 5200, the 7800 does NOT have a vertical blank interrupt. A way around this is to put a single line region at the very end of your display list and set a Display List Interrupt on that line. This way you will get an NMI to the processor at the end of the display list. Dan

If you haven't already, be sure to check out the Programming message board here at Atari Age. There are a couple people there working on 5200 games and we have some pretty active discussions on the topic. Dan

This may have just been a typo, since you seem to have the idea: cmp joy_down should have beeb cmp #joy_down Dan

quote: Originally posted by AtariDude: Assuming that someone could get a program to work with an emulator, would that program work on a real Atari 2600 / 7800 machine, assuming that the bin file could be converted to a real game cartridge? Star Fire obviously works because it's been tested, but in general the answer to this question is not necessarily. Just because a game runs on an emulator doesn't mean it will run properly on the real hardware. Dan

Since we are talking about Synapse games how about Protector (I and II), Fort Apocalypse, Shaums and Zepplin, all great games! Dan