Video Game Hardware Mods and ROM downloads.

Development Cartridges for the Atari 7800 Development System:--->  devcarts.pdf  (Revision 14, 2003)

What's new in Devcarts.pdf?

Rev 14:-

-    Corrections made to instructions for linear dev cart using built-in RAM. (Thanks Happy_Dude!)
-    Linear 32K FlashROM dev cart added. (Replaces EEPROM cart).
-    Document reformatted with better page margins.

-    Atari 2600 Ramona dev carts added. Support for 2K, 4K, 8K/F8 and 16K/F6.
-    Summary of differences between using a DevOS console and using Ramona dev carts
-    Suggested bankswitching schemes for Atari 2600 games larger than 32K
 

You will need Adobe Acrobat Reader to view the above document. Free from http://www.adobe.com.

Christmas 2000 I converted one of my 7800 PAL consoles to a development system as designed by John Saeger and Eckhard Stolberg. This is a ripper which lets you dump 2600 and 7800 games straight to your IBM compatible PC. (Must be DOS operating system. ie. DOS, Windows 3.x or Windows 95).  John Saeger had also designed a development cartridge using Static Random Access Memory (SRAM) that allows you to upload many 2600 and 7800 games from the PC to the 7800 console where they can be played as long as the console is kept switched on! Great I thought! After some initial trepidation I managed to build the original 32K dev cart by John Saeger. This worked surprisingly well! Impressed by all this I embarked on a "dev cart crusade" together with one very helpful Eckhard Stolberg, the results of which are presented in the portable document above. All carts should work equally well on PAL or NTSC systems. In most cases I have built two or three working examples of the dev carts described. The original OpenOffice.org document used to generate the PDF is available in devcarts.zip  and original QCad logic drawings used in the PDF are available in logic.zip.

I wish to extend a huge thankyou to Eckhard Stolberg who's thorough understanding of Atari programming often made the difference between a working dev cart and a lame duck. Eckhard has recently written a number of enhancements into his development system control programme 7800ctrl.exe, including full support for the new bankswitching dev carts.  The stand alone dev cart with built in BIOS routines is also a brainchild of Eckhard's for which he has written the "Ramona" BIOS.  This cartridge allows uploading of games to an unmodified 7800 console! You will need the latest version of  7800ctrl.exe to upload to any of the bankswitching devcarts and you will need the Ramona BIOS copied to an EPROM if you intend making one of the stand alone dev carts. (Refer to http://home.arcor.de/estolberg/index.html).

If you plan on building a 32K/F4 dev cart then download Eckhard Stolberg's test program  f4_test.bin.

Thank you also to the University of Oklahoma who taught me all about digital design.  Take a look at  http://coecs.ou.edu/  .

If you are confident with a soldering iron then the best "bang for buck" comes from building the 144K bankswitching devcart plus the combined 8K/F8 & 16K/F6 devcart with Super Chip RAM. If, on the other hand you are inexperienced with a soldering iron then it is still worth trying the 48K linear dev cart which supports a good many games for it's size. Bear in mind that only the Ramona dev carts will work on an unmodified 7800 console. All other dev carts require a 7800 dev system (ie. an Atari 7800 console with DevOS BIOS installed) to work.

The logic diagrams supplied in devcarts.pdf are for information only and are not required to build any of the dev carts.

Atari 7800 PAL ROMS

These are all the PAL roms for the Atari 7800 that I know of. If you find or make another please tell me!

Convert 8-bit NES control pad to Atari 2600/7800:-

I always play my 2600 and 7800 systems using an 8-bit NES control pad. (I'm certainly no purist).

List of games on the Atari 2600 Jnr with 128 built-in games:-

Note on converting Sega Master system light gun to Atari 2600/7800:-

Examples of Basic programmes for Spectravideo CompuMate:-

Original Drawing of link cable for two-player "Zero Tolerance" (Megadrive):-

"Zero Tolerance" is a rather good first person shooter for the Sega Megadrive (Genesis), a la Wolfenstein. Technopop, the developers of the game took the unusual step of including a two player cooperative game which relies on the use of two complete Megadrive setups linked together through the second joystick port. Each player must have their own TV and copy of the game. (The link cable is not compatible with the Sega Nomad unit).  Also, there is no reason you can't deathmatch too! I patched a cable together from two old joystick leads (each had all 9 wires) which is about 12 ft long and this works fine!

If you like "ZT" then give it a try

There is an excellent review of ZT including screen shots at http://www.shinforce.com/genesis/reviews/ZeroTolerance.htm  and a complete set of level maps at http://www.gamesdomain.com/solution/zero_tolerance_map.txt

And here is some trivia:-

In 2-player mode, the other player can be seen to rest on one knee when he ducks down. (A + down), and he will do a "stiff" jump when he jumps (A + up), or slide from side to side (strafe = A + left or right). A normal walk is animated.

From an uncleared level you can walk back up into any of the previously cleared levels (but not back into "boss" levels). There will be no powerups there but all the dead enemies are present.

Convert Sega Megadrive (Genesis) control pad to Vectrex:-

I once purchased a Vectrex video arcade unit which lacked a controller. This is how I got to see it working! Worth the effort too!

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Copyright 2003
Graham.J.Percy

contact:- gjp57@yahoo.com

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