Mark's Projects

Here are some of the projects that I have been working on. This page covers projects dating back to 1996. Note that this is a very small percentage, just showcaseing the neater ones that people would actually care about.(Questions? Mail Me!)

Orion Intelliscope computer locator

I recently go my Orion XT10 intelliscope with the computerized object locator.   I love it, but realized that many others out there were interested in trying to connect the object locator system to other telescopes.   Further, Orion says this is not possible.   So, taking this challenge, I have completly analysed the system, it's encoders and the controller so that others may use this data to install the locator on a different scope.   My efforts can be found here: The Intelliscope System.

How to Create Vectrex Overlays

When I created VeCaves, I also created an overlay for it. I included the overlay when I sold the VeCaves/Spike's Spree cartridges. Many people have asked how I created the overlays. Because of this, and the fact that I would appreciate other homebrewers to make overlays, I wrote up the method I used into a web page. Go to it here: How to create an overlay.

Vectrex games: VeCaves and Spike's Spree

I've created my first two games for the Vectrex. VeCaves is a very addicting twitch kind of game. It is similar to the caves game for the palm. Spike's Spree is a combination of fastfood for the 2600 and Spike. Like fastfood, objects come from the left side of the screen. You move Spike around to catch them. The trick is that almost half of the objects will kill you if you catch them, and the others should be caught in the correct order. This makes for a frantically fast paced game. Here are short movies of each:

VeCaves.mov 2354776 bytes

SpikesSpree.mov 1261120 bytes

Although I sold out the several runs of VeCaves and Spike's Spree as a double cart, I am taking names for those interested if I make more. If you would like to add yourself to the list, please Mail Me.

Atari 2600 TIA schematics

This is not really a project in the true sense of the word as I'm not really making anything, but I list it here because it is something I am spending my time on, and I know there are others interested. I finally got ahold of the schematics for the Atari TIA, which is the graphics chip inside the 2600. It is an ASIC that was designed back in 1976. Anyway, I scanned them in for others to look at.(Yes, I used a 3ft wide scanner) These are 5 sheets of hand drawn schematics, which measure 2ft by 3ft. I've included 2 scans of different resolutions. The first is 100dpi B/W(1 bit color). If this seems like a low res picture, yes, but realise that they are 1MByte uncompressed per page. I've saved them as LZW compressed tif's, and bundled them in a zip. The result is readable, but is a little blurry if you plan on actually looking at the logic in detail. The second is a 400dpi B/W. This is a good resolution to read the schematics. These are also LZW compressed, making them 2-5MBytes each.(pretty good considering this is a 14400 x 9820 pixal image; yes that is 141 mega-pixals)

I've removed these from my site to save space. Thankfully AtariAge has volunteered to host them. Find them here.

If you need a viewer to read compressed tif documents, check out IrFanView, which can be found at here.
I also have a set of 400dpi 256 shade greyscale scans. They are to large to put in my web space(or generally on the web), but they will fit on a cd if compressed. If you want a cd with these scans, let me know.

Vectrex 3-D goggles

I realised that I really wanted to have a set of 3-D goggles for my vectrex so I could play the 3-D games. But, I didn't want to pay $300 for one, and decided to make my own.

I don't have close up pictures yet, but the jist is that I used a portable CD player as a frame and motor mount. Then I used a clear CD(from the bottom of a CD-R spindle), and printed the appropriate colors on it to match the original wheels. I rebuilt the original circuit which powered the cd motor, and took in a signal from my opto-isolator to provide a sync signal back to the vectrex. The cd player has 2 eye holes cut into it, and I mounted the whole thing on the front of a pair of safty goggles to hold it on my face.

Overall, it turned out very nice. I've compared it to an original, and decided that they work identicle. The only downside to my creation is that it looks stupid wearing a cd player on your face...

This is not me, but a friend of mine.

Vectrex light Pen

I also rebuilt a Vectrex light pen. I simply used the methods described on Brett's Vectrex Presearve.

Portable Atari

I had decided that I wanted a portable to try out games at swap meets etc. I've checked out the VCSp, and did a self check, to realise that I was not deticated spend enough time on it to go crasy in making it small. Thus my design goals simplicity in construction, longer battery life, and big screen. I ended up putting a 4in TFT LCD, and I'm glad I went that big. I find it kinda difficult to see many games on it, so a 2in screen would be just impossible. Luck had it that the "mobile monitor" sold for the PS1 is a perfect fit, as it is reasonably priced, doesn't need a tuner and is widely available. I built the 2600 main board into a speak and spell, which is a very convenient carrying handle, and enough room to add the main board of a 2600 6 switch without cutting into the circuit board(remember the part about not wanting to spend much time?). I hope to have pictures soon.

Atari 2600 Anygame cart

I designed and created a battery backed SRAM cart for the 2600 cart. It works off the parallel port and is designed so that a simple dos copy to lpt1 will program the cart. I also did a dos program to send games. No, I don't have schematics, or anything like that, I kinda just made it up as I went.



Video Simon

I've been working on Atari 2600 hardware for a while now, and realised that I had never actually made an Atari program. So, I had some free time, and 1 week later, I had Video Simon. It's kinda silly to play Simon on the Atari, but I made it as a programming excersize, so it's alright. Unfortunitely I do not have an actual Simon to imitate, so I had to go off of my memory of seeing one a decade or so ago. But I think it is pretty close. So, here, take a look at the game, take a look at the code, let me know what you think.

The final version has been released, and can be purchased from Hozer Video. I'll even tell you a little secret; if you make your own game,then sell it through Hozer Video, you can apply your royalty to other games to get them for free! See my main page for links to sites on how to make your own Atari games.

Atari 2600 Game Server/Development System

I built this to play with. It currently is only a game server, but I have plans to make it a full development system by adding a text editor to it, and a 6502 assembler and disassembler. The system has a 4 line by 40 character backlit LCD display, buttons, a control knob(shaft encoder for the technically inclined) and a cartridge socket built into the front panel. Inside, it runs on an Intel x86 processor(the 80C188EB embedded processor), has 2 512kbyte EPROMS to hold 256 4k games, a 64kbyte EPROM for the game names and instructions, system ROM and RAM, and interface/support logic. This system works with an Atari 2600 with no modifications. It has 2 cords coming out of the back, one that plugs into the Atari's cartridge socket, and one that plugs into the Atari's power socket. Through a menu driven interface, the user can browse through the list of games by name, view instructions and play one of the internal games. The user can load any game into memory, edit the game(for Game Genie/Chetah type cheats), and play it out of memory. The user can insert a cartridge into this system to be loaded into memory, or played directly with the atari(to support bankswitched cartridges, but cannot use cartridges with RAM). Any game played is setup to run on the Atari, and the system automatically resets the Atari to start the game up. Also included in the menu is a setup to change system attributes.

I don't have a picture of the system yet, but here are some of the technical files, that you may be interested in. Note that if you plan on using these for constructing one yourself, or designing your own similar, you should mail me) to find out all the little tricks I learned, and problems the system has(and how to fix them). These are only the most recent versions. The schematics are all in postscript format. Sorry for the inconvienience, but if I were to convert them to a standard picture format, it would have to be an extremely high resolution(and hence large file) to be able to read some of the fine details. With postscript, you can simply zoom in to any detail.(or print it to the resolution of your printer) Note that these files are extremely technical. In order to build this system, you need to have had training in computer engineering, or have extensive knowledge in embedded system design and construction. I would consider selling them, but because of the extensive construction time involved, I would have to ask for more than anyone would be willing to pay(the hardware is worth about $150, but labor would raise it to $500-$1000).
Schematic of main system board
Schematic of game bus board
Schematic of power & periperial board
Schematic of off board wiring
Code to run the system (note that this version of the code is writtian for Borland's turbo assembler to be run on an 80C188EB with a monitor program. To be burned onto an EPROM and run directly, some segments definitions must be modified, and some additional setup added. It still runs with a monitor because I am still developing the system. Let me know if you need a monitor)
Game data

In the future, I plan to add quite a few additional things. I plan on including 8 and possibly 16k games in the internal ROMS, and adding hardware to support the bankswitching. I know how I am going to do this, not too hard, just a pile more chips. Also I will add a serial interface to a PC that will allow any game to be sent to and from the system, including one you are in the process of writing. With this, I will also add battery backed up storage to save a few of these in the system. I'm also going to make a cartridge with EEPROM and the appropriate interface so that I will be able to program any of the games onto this standard cartridge that can be played on any Atari w/o this system. Future intent is also to add a 6502 assembler and disassembler onboard, but that will mainly depend on wether or not I start programming for the Atari.

My MacAquarium

I built this intersting little toy for fun. There are many displayed on the web, generally following two basic types, the original by Andy Ihnatko involves a small whole cut in the top where the hand hole is normally. It's problem is that it is very difficult to get access to. I have seen another type by Jim Lower who makes the entire top panel removeable, but the seam shows. I decided to do better. My design doesn't have any cuts in the case. I modified the Plus case to slide out. This way there are no seams and you have full access to the aquarium. It also allowed for a few other neat things! My goal, not caring about the actual fish, was to have this really neat noval thing. I wanted the aquarium, and the fact that I needed fish to put in it was just a side note. So along these lines, I made it as close to the original plus as possible. I took a screen shot from a working plus, and printed it on a transparency which was placed on the back wall of the aquarium. I also put a diffusion filter and installed lights behind. The effect was that it glowed that all to familiar plus glow. I built a dimmer in so that when you adjusted the brightness knob on the front, it dimmed the light. I also wired the power switch to the light. The power was of course supplied throught the normal power socket. I epoxied the front keyboard jack, and back panel jacks. I left the disk drive in place to add to the realism. The only thing I didn't do that I would have liked to is to make it work as a mac as well. The problem is that there isn't enough room to reinstall the picture tube, and I don't have a LCD screen that size. You can see most of these modifications in these pictures.

My Jacob's Ladder

I built this because it is just plain cool. No matter how long I look at it, it really is darn impressive. The picture doesn't show it all that great, but it's the best I have. A little description first. It stands four and a half foot high, with the poles being two and a half feet long. It is 18 in. wide by 14 in. deep. Which makes it pretty big. I have a 12000 volt neon tube transformer powering it.(That is of course RMS, making a peak voltage of 17000 volts for the non-electricians) This starts the arc at one half inch at the bottom and expands up to 3 inches at the top. The transformer is supplying 30mA(alot for 12000V). This makes for a very good show because it sustains a fairly wide discharge that gets to about one half inch in diameter. You can just see an arc on it's voyage to the top in this picture.


I have also made a bunch of other things that I have not shown. These include, but are not limited to:
*A variable power supply with multiple fixed outputs and digital voltmeter.(Pictures Forthcoming)
*Power control center
*Power switching alarm clock.
*High current(20A, 0-120V) variable AC/DC power supply