Hiya from El Paso

[nathanallan]

Hiya guys,

I was recommended this forum by people at atariage because I am interested in homebrewing for my Odyssey 2 console.

More of a hardware thing, I want to see what more I can do with a different main processor, maybe different video chip and add the typical of add ons (AV jacks, wire for different controllers, internal power supply). I'm not so good at making games for things, really. I really like the hardware aspect of it , though!

IMHO Magnavox really dropped the ball by not having another machine like the O2 (I dunno the O3 would have been cool), we might have more of a richer gaming scene today.

Anyway, I live in El Paso, TX, and I like to tinker with electronics; I am a computer network tech by trade and really like what I do. Anything electronic I seem to have an affinity for, even if I don't know anything about it. I just like them!

My O2 has really gotten me intrigued, as it's a single chip design, almost! I want to do MORE with it. It's too fun of a machine to NOT want to do more!

Nice to meet all y'all.

Nathan

[Janzl]

Hi Nathan,

Welcome to the forum, always nice to see a programmer show up here. People over here are very hungry for homebrews!

Check the forum's programming links, they should give you a nice place to start!

[Rene_G7400]

Yes, doing hardware experiments with this console is fun, and even more if you have a Videopac G7400 (the european version of the Odyssey3).

Even without opening the console you can add a lot of different circuits, since the cartridge port contains several useful signals (like Read, Write, Chip Enable and a free input of the 8048 microcontroller).
It doesn't have a video input, so adding a videochip might be more difficult.

The Videopac Chess and Basic modules have their own (Z80) processor, so communication between the internal 8048 microcontroller and an external processor can be done through the cartridge port.

[manopac]

welcome ! and am really curious what you would come up with 

[nathanallan]

Thanks for the warm welcome

There definitely will be some coding going on, but I am no programmer. Definitely a hardwar elover, though. Also the Z80 is a favorite processor of mine, too, so knowing that those carts have one in there make this even more exciting for me. The links will prove extremely valuable!

A few of the goals I would like to see come to pass are:

AV out,
internal power supply with only AC cable going in,
external keyboard (keep the original there, the Internal Collector demands it),
faster running processor,
real time clock and maybe built in user "shell,"
some sort of I/O most likely RS-232.

I am going from the inside out, but having a very robust cartridge port helps a lot so that I might stay external for a lot of it.

The whole of the O2 is really fascinating, as there is SO much room inside the case and such a small part of it occupied. It really does seem that Magnavox watered it down tremendously when it went to production; lots of corners seem to have been cut.

Soon I hope to get a second one, I only have the one to experiment with.

Not going to re-engineer the whole board, but try to make it a bit more than is there since it seems like it "could have been."

I am still in the homework stage and it looks like it is slow going since I do have real life to worry about first. This is my new pet project, for the long haul.

Great to be here!

[ozyr]

Nathan, if you can get a good AV out, I'd like to know the secret. I've been trying off/on again for years, and have yet to make it work properly. Video is always muddy, incorrect colors, and poor sound. At this point in time, I don't know what to do (not big on electronics).

[Seob]

Welkom aboard. Keep us informed. Like to see what you come up with.

[Rafael]

Hi, I´m superbee on AA forums. Welcome and let us know about your projects.

[nathanallan]

@ozyr I am thinking that if I remove or bypass the RF out of the machine I can clear some of that up-- I have read and had PM conversations with people that had the same things happen to their mods, it just didn't work right. Also I was advised to put a small amp inline with the video and audio, so I might give that a shot, too.

I'll definitely be keeping a bit of a log here on this forum when I do things concerning my Odyssey. Great that you are here, superbee aka Rafael! I wonder how many users are here from atariage or vintage-computer?

Something I forgot to mention is that I want to have a keypad port mod, to use an Atari style keyboard controller, only because I want it to be that way.

Life threw me a curve ball so things are going slowly, but that's okay, they will proceed. The O2 being the smallest of my projects, it has precedence

[Seob]

well i'm also active on atariage. My name there is also Seob.

[Rafael]

I'll definitely be keeping a bit of a log here on this forum when I do things concerning my Odyssey. Great that you are here, superbee aka Rafael! I wonder how many users are here from atariage or vintage-computer?

Well, where someone is talking about Odyssey I´ll be there

[nathanallan]

Well, I have been doing a lot of homework and lots of emailing to different people that have done things with the O2/Videopac, but it's mainly homebrew games and AV mods. Not that those aren't cool, but it doesn't make it more of a computer, just a better game system.

Does anyone know of any already done projects involving the 8048/8075/8055 and a Z80? I got the crazy idea to embed a Z80 inside the O2 so it can be the serial port controller, but I cannot find where anyone has attempted this, and I have been looking off and on for a few days now.

From all the reading up, the 8048 has to be replaced with something that can hold more code to support a serial port, there is more rom on other chips. Also, custom code must be written to make it see any data coming through it, or to access it in any way. I am thinking some sort of external drive, or at least able to send bits to another serial port (ala null modem to something else with hand typed instructions).

A lot of people are on about graphics and updating the chip, but that's not the main thing for me, the graphics are pretty good as they are (for the era) and not a major thing to me.

Any ideas on how to interface a Z80 to this?

Also, I want it to be inside the console, so there ought to be some kind of instruction to let the machine know that there is a cart in and to refer to that, OR there is no cart in and refer to data from a serial port, I figure this could be done from the Z80 side of things.

The greatest thing about a project like this one (vs. the many other projects I have tried to tackle) are that the parts are out there already, nothing much has to be developed and it's nie to work with things that are well understood (for a change, I got a bad experience working with IPv6).

also posted at vintage-computer forums

[Seob]

Try finding a basic module. Open it and hack it. Our try to search the schematics for the basic module. I'm sure rene has them. This might help you with your project. The schematics are here in this subforum http://videopac.nl/forum/index.php?topic=1067.0
This site has a lot of info about the 8048, and build your own z80 computer. http://www.coprolite.com/
Here is a list with articles on the odyssey2 http://www.coprolite.com/allarts.html

[nathanallan]

Excellent links, more homework (a good thing), thanks!! The 8048 instruction set looks particularly useful.

[Seob]

Here is a how to, to get 2600 joystick working on the odyssey2.
http://www.the-nextlevel.com/odyssey2/articles/2600joysticks/index.php