Dr. Van Thorp

The 800 was the only one with 4 joystick ports (aside from the 400, which has a lousy keyboard). There is something to be said for that. Why was so much software written that required more memory than the 800 had? Seems like a developer would have been giving up a big chunk of the market.

3-D Star Field is pretty easy. It is just an array of x,y coordinates for each star. Each star is assigned a random screen position and random brightness (withing limits of the display device's ability to show brightness), and each moves at a random speed across the screen, all in the same direction. With each cycle of the game loop, each star erased and redrawn in a new position based on its speed, and it's coordinates are updated. When stars get to the edge of the screen, they get wrapped around back to the other side, and the speed and brightness (possibly vertical position) might get assigned new random values.

I remember a very early comparison of game consoles in an old Consumer Reports, that ranked the Bally machine above Atari, Intelevision, and others as the best of the early consoles. There was a users group for people that programmed the console through the BASIC cartridge. The machine had a calculator keypad, and paddle knobs built in to the tops of the joystics. You could move a character on the screen and aim it's weapon with the knob; a sophisticated controle feature for the time. I remember playing with it in a Wards store. I allready had a Commodore 64, but this console looked like it would be cool to own.

Compute magazine also had an article about the Armitron. The Compute article gave instructions for dismantling and replacing part of the gear mechanism so that different parts of the arm could run off differtent moters which could be seperately controlled by the computer. You might want to look for this article.

Well, I remember reading somewhere that the Sega Master System had most of the same internal hardware as the Colecovision, so if the graphics really were better than the NES, it is because the people designing the game graphics were better at it than the guys designing NES graphics. Was it possible to build an adapter to play Colecovision games on te SMS?

Well, back to the original topic, I suggest buying the XGameStation Micro or Pico edition, using it to learn the hardare, then building something similar. You could use the basic XGameStation design as the graphics proccessor for your machine. There is a guy on the XGameStation message boards that is working on a project like this. I think that a new old-school machine shoudl probably use a 16-bit 6502-series CPU, which is still being manufacutred. You should read up on the Amiga's specs to get ideas for what kind of graphics and other hardware capabilities you want. Amiga was a sort of successor to Atari's 8-bit machines, and designed by the same guy, so if you like Atari 800, you should love Amiga. A flash-card reader would be a nice addition.

For the record, the C-64's multi-color hight-res mode uses 4x8 cells. It looks like the graphics in this game were very carefully designed to that, even though there are more that four colors in the background (I see purple, yellow, two brownish tones, and black) there are only four colors per 4x8 cell. You could also get around this limitation by using multiplexed sprites for parts of the front scrolling layer or primary plane. In your sample picture, the back plane, with the rock shapes, looks simple enough that you might be able to do it with sprites. If you can manage to create one of the scrolling planes entirely from sprites, this will same a lot of code and a lot of run-time proccessing time. And if you are using a "00" pattern in memory to represent holes in the primary plane, then you don't need need a hole map. The 00's are a build in hole map.

Well, the Atari and C-64 had very similar graphics capabilities. The Atari had more colors; the Commodore had (I think) a better system for mapping colors on the screen. I think that Commodore's sprite system was better, but I'm sure someone will disagree. Both machines have better graphics than the Apple II. Has anyone made a web page comparing old eight-bit machines, with descriptions of how the graphics modes work?

I don't ever remember seeing Jelly monsters. I remember that Cosmic Cruncher was a fairly close Pac Man clone with one bug: sometimes when you tried to turn a corner in the maze, the edge of the pac-man (shaped like a commodore logo) would get catch on the wall, and you would have to move sideways a little bit to get unstuck. A fast-moving game like that shouldn't require single-pixel precision. I had the VIC-20 for less than two years before I got my C-64. Looking back, I beleive that the VIC, like so many other old machines, was rarely used to its full potential.

There was an off-brand clone of Pac-Man for the VIC-20 that was pretty popular. Snack-Man was sold primarily through a little black-and-white ad in the back of computer magazines, and many pirate cassettes circulated as well. It wasn't even an official Pac-Man game, but I liked it better than the official versions I played. The game used the VIC-20's character tile graphics, which jumped across the screen by eight-pixel steps, but is was so fast you couldn't tell; when I played the Atari-8-bit version later, the official game seemed sluggish.

Yes. In the beginning, every platform was open to development without fees. It was only later that game console manufacturers got greedy and started using proprietory encription, cartridges, etc, to force software companies to pay licensing fees.

At one time, Atari developed an upgrade called the "Graduate" that turned the 2600 into a full-fledged computer with keyboard, programability, external storage, etc. The add-on was the creation of a team of engineers that defected from Commodore to start their own consulting/engineering firm. The add-on was to have contained its own CPU, and the 2600 would have acted much like the graphics card on a PC. Shifts in the market, including a surge in the popularity of the C-64, caused Atari to re-thing the project and cancel production. It would still be an interesting hobby project.

Yes, there was terminal software that would make 40-column machines like C=64 and Atari 8-bit display eighty columns of text. My experience was only with the C=64 software. This software displayed eightly columns on the hi-res screen by displaying 4x8 pixel characters. On a TV set, the little half-size characters looked like blurry mush, but on a good monochrome monitor, it was completely readable. Funny thing about 4x80 pixel fonts. This is enough room to make some letters readable. E's, F's, R's, etc, could be made recognizable, but the designer of the font would have to cheat a little on letters like M and W. Sometimes a single letter by itself would be unrecognizable, but when you saw it in a word with other letters, you had no problem reading it. The terminal software seemed to be able to display 80-column text as fast as my 1200 baud modem could download it. The only delays occured when the cursor reached the bottom of the screen, and the text needed to scroll. It would take maybe a half second or a second for all the graphics to be moved up eight pixels.

I see posts discussing an project to build a dual-graphic chip computer to create more colorful graphics displays. How about three sets of graphics chips, hooked up to an RGB monitor?

Somewhere on the web, I once found very detailed documentation of the Odyssey 2's inner workings. It is actually more advanced than the 2600, but seems to have been designed with very specific game ideas in mind, which makes it limited in some ways. But I think that it is a very capable machine, and its potential was never fully tapped.

Yep. I remember computer and console games costing 20 to thrity dollars, and the link to the old ad confirms this. But I have also found boxes for old Atari 2600 games with fifty dollar price tags. I think that Atari was screwing their customers hard on the early releases of games like Space Invaders, then lowered the prices when they had saturated the "early adopter" market.

Thanks. I'm surprised to learn that Apple was willing to sell ROMs without proof of ownership of the computer.

Something I wondered about years ago, and a web page I recently found reminded me of it. There used to be an ST cartridge called "Magic Sac" that made the ST run Macintish software: Magic Sac When it was released, magazine articles explained that you needed authentic ROMs, "ROMs pulled from a Mac 128 or 512". I'm guessing that this phrase appeared in the product literature, because it appeared in every old article mentioning the device. My question: where the hell were the ROMs coming from? Did people really canabalize expansive Apple machines to make a cheaper machine emulate the MAC? Was there an underground market for Apple ROMs from discarded computers? Or was "ROMs pulled from a Mac 128 or 512" code words for "pirate ROMS" as I've allways suspected?

No. I am only an observer.

How about the Intelevison? It has fairly small and simple 1970's era innner workings, but doesn't have anything weird like the 2600's video kernal system to emulate. Unless there is something about Intelevison that I don't know, you would basically be writting a sprite and tile system and an interpreter for 16-bit opcodes.

Colecovision programming is a very small subculture. Also, maybe they are on a different message board.

A custom chip would be a dream. I do not think it will happen. 860177[/snapback] Well there might be another, simpler approach to the problem. I have read about chips celled BASIC Stamps. These chips contain a microproccessor with a BASIC ROM, and are mostly used for embedded applications like controlling machinery. I'm guessintg that they are quite a bit faster than the 25-year-old 6502 chips in Atari 8-bit computers. A hobbyist might be able to build a similar device that would run atari compatable basic on a much faster CPU. I imagine such a device being plugged directly in to the Atari motherboard, possibly as a replacement for the actual 6502 chip. The Atari BASIC stamp (as I would call it) would have Atari basic on ROM inside of it, which would be a newly rewritten fully compatable Atari BASIC that runs native on whichever high speed proccessor is used in the Stamp. The Basic Stamp would also be able to fully emulate a real 6502 to run all of your existing non-BASIC software, Atari DOS, BIOS ROMS, etc, so you would almost never have to remove the device. You could run the BASIC Stamp with the actual Atari BASIC cartridge plugged in, in case a peice of software needs to read something from the BASIC ROM. Does this sound feasable?

Do you intend to impliment Atari BASIC in FPGA?

Space Fury might be the first that I remember. It had a voice that said "A creature for my amusement; prepare for battle" in sync with an alien face on the screen:

Would it ba possible to add hardware to a colecovision to make it into an MSX machine? Has anyone done this?