Lets learn how to hack! A beginners guide.

[Pac Munchkin]

I have been thinking there are a lot of people that like our hacks but would like to get into hacking them selves.

Many good ideas never see the light of day simply because of a belief in limitation, remove that belief in limitation and you have a new found sense of adventure that you can learn and you can be as good as any one else if you are willing to learn to be.

 

I will give you essential tools I use most in hacking that you can too.

 

These are all easy tools nothing hard to understand.

 

The tools I use are

Stella

Bit Hacker (some prefer Hack-O-Matic II)

Showgfx

File Compare

and a ROM called Colour Test

Also good to have is a Decimal to Binary converter (this can really speed things up for hacking)

 

All of these are my tools I use.

 

Ok if you have all these tools you are ready to start hacking!

First is there a hack of the ROM you what to hack already preferably with color changes?

This hack can not be a radically different hack like extra levels or different game play that is getting into advanced hacking. It should be the same except for graphics and colors.

If you find one this will help you out a lot, I did this when I found out Tom Boy is really a hack of Pit Fall now I had two very different appearing and sounding even playing games to compare with each other.

 

If you have found the one you want to hack and another that has been hacked or as in the case of Tom Boy the original it came from you now can move on to the next step.

 

Copy both ROMs into the folder for Showgfx this should be in a main root not in a bunch of sub folders.

After you copied both go to the [start] button then go to Programs Accessories and Command Prompt.

This will put you in DOS the system Windows is operating from, type cd .. and press enter keep doing this until you see only this C:\ once you see this stop. Is your showgfx in the C:\ directory or maybe on another drive maybe D:\?

I'll show you how to get to another drive lets say D:\ for example just type D:\ and press enter this puts you into the D:\ drive (if it is in C:\ there is no need to switch) now type CD 2600showgfx and press enter. Doing this now puts you into the showgfx folder if that is the location of the folder you put it at in windows.

Type dir press enter you will now see a list of the programs including the ROMs you just copied. (it is good to rename these in windows to something like old.bin and new.bin (the one you don't want to change and the one you do want to change) so in this list you will see old.bin and new.bin next to these you will see a number that is the amount of bytes these have. It is important to find these, 4K ROMS would be 4096 so next we type showgfx old.bin 0 4096 > old.txt

Press enter this will convert the old ROM to a text file. Do the same thing for the New.bin as well.

Now type Exit

Go back to the folder in windows click on Old.txt and open with the File Compare, it will ask you for the next file click browse and load the new.txt. Now it list both side by side you are now looking at both ROMs both the one you want to change and the one you want to compare it to, these as I said should have color differences maybe sound differences as well don't worry so much for graphics as those are pretty clear to see without comparing.

Click on highlight differences, it will now one at a time find every difference between these two ROMs.

When you find a difference Open Bit Hacker load the ROM you want to change save the ROM as something like 1Test Now scroll down locate the same number you found the difference at change that (note try to only change one line at a time otherwise you will not know which line had what effect of change) after you have changed that load up Stella and load the new 1test ROM you just made, play the game and look for what was changed, does it sound different, are the colors changed some place? If you just found a change you just found your first thing you can change to what ever you chose. Lets say it is color and you want a certain color, close that ROM and load up Colour Test in Stella, use the joy stick to find the color you want to change that to once you have found it write down the number.

Go back to Bit Hacker now here is where it gets a little hard but stay with me I'll talk you though this.

those little black boxes and white boxes represent one number each line. It is called Binary numbers this is what the computer understands, it is based in increases of 2 our number system we are use to is based in increases of 10.

Starting from the right most box this can be 0 or 1 (simple on off, no box or black box)

Next to it we have the on off bit for 2 (so if I wanted to make a 2 the second box would be checked, now don't get ahead of me and think if I wanted three the third box would be checked on!)

So 2 would be nothing in the first box, black box in the second box.

3 would be 2 + 1 or The first box black and the second box black.

So now we come to 4 which would be the third box black the first and second box clear.

this adding continues on like this 1 2 4 8 16 32 64 128 (that is what 8 bits looks like or also called one byte)

By the way when you get to color 255 you do not need go higher they repeat over and over again on that, also the colors go in twos as well so color 0 and color 1 is black (this holds true for all colors up to 255 which really means 128 colors) another good tool to have is a decimal to binary converter or use your math like this, what is the highest number not going over the number you want click that bit what is the next highest number you can add to that, click that bit the next highest until you get to the number of the color you wanted.

Now after you get your color all punched in save the game again, go back to the 1test and look at your results, do you like what you see? If you want it a little darker you can remove the lower bits, it you want brighter you can add lower bits. So say you want it darker remove the first row to the left if it is a color that does not have any bits from 1 to 4 checked this will not work and you need to go back to the colour test to find a more suitable color.

Ok that is only changing one line lets say now you are changing the color of one line in a sprite (one screen graphic like a man or space ship) now you can try changing the line above it or below it if you see a pattern there like a bunch of lines that look the same straight down you can be pretty safe changing them all and find you just changed the colors of the ship or person or what ever it is you wanted to change.

For sound like I did for Tom Boy to Tarzan I found the lower the number the higher the sound went the higher the number the lower the sound went.

Don't be afraid to experiment my whole hacking method comes from I wonder what would happen if I changed this.

If it has no effect change it back, if it crashed change it back always keep track of what you changed and what it was like before you changed it, this can be done using two Bit Hackers side by side same ROM One is the one you are working on the other is only for reference of what it looked like before you changed it so you can change it back if you need to.

Look for patterns of sameness in the bits those may be color or sound but not always there are games that use only one line to define the color of a whole sprite so it is only one color, these are harder to find but can be found.

Now for graphics that is simple scroll until you see the players or space ships or what ever you want to change, then change the bits all around to look like what you want. (if it is upside down switch the order in view to assend) The only rule is to try to keep it the same size no bigger than the original but again sometimes you can go bigger and be safe. See if you go beyond what the ROM is suppose to see you may be making your sprite part of another sprite or worse part of data of the game.

Anyway again if you mess up you can always go back and change it back.

 

That is how I hacked Tom Boy into Tarzan

 

I found other things as well like how to make the gators deadly which in Tom Boy they were not as they were only rocks, also tree placement and pit placement all from finding differences and testing what those differences did.

 

By the way for sound at lest in Tom Boy and Pit Fall if you click the high bit 128 that turns the sound off or ends that sound it is playing. Like saying start sound stop sound.

 

Enjoy your adventures into hacking!

Wade

 

 

If you want to hack something that has not been changed before remember look for patterns in the bits of sameness then add or subtract lines and see what happens, do any colors change did the sound change see it is all simply change this and see what happens.

 

If you want to get into disassembly I am not the guy to ask about that.

Edited August 14, 2006 by Pac Munchkin

[Pac Munchkin]

It has been brought to my attention to give links for everything I talk of along with the ColourTest.bin So I am providing all of this here and now. Everything is 100% FREE!!!!!

 

 

 

http://www.bjars.com/tools.html

 

Here you will find most of the tools

 

 

 

http://www.download.com/Files-Compare-Tool...tml?tag=lst-0-1

 

Here you can get the file compare tool I use

 

 

 

http://www.mistupid.com/computers/binaryconv.htm

 

Here is a Binary / Decimal Converter Calculator save this page it works off line too.

 

 

 

Ok enjoy getting started hacking

 

Happy Hacking

Wade

ColourTest.bin

[+Random Terrain]

In case you'd like to know, I have a Hexadecimal / Decimal / Binary / Octal / Quintal / Ternary Converter on this page:

 

http://www.randomterrain.com/atari-2600-me...tools-toys.html

[jwierer]

Here is a Binary / Decimal Converter Calculator save this page it works off line too.

 

The Calculator in Windows (Start->Programs->Accessories->Caclculator) does HEX, DEC, OCT, and BIN conversions. You just need to change the view to scientific.

 

-Jeff

[Pac Munchkin]

In case you'd like to know, I have a Hexadecimal / Decimal / Binary / Octal / Quintal / Ternary Converter on this page:

 

http://www.randomterrain.com/atari-2600-me...tools-toys.html

 

 

WOW excellent I love it, I also love the other tools you have as well!

 

Excellent site!!!!

 

Thanks so much!!

 

Wade

[Pac Munchkin]

Here is a Binary / Decimal Converter Calculator save this page it works off line too.

 

The Calculator in Windows (Start->Programs->Accessories->Calculator) does HEX, DEC, OCT, and BIN conversions. You just need to change the view to scientific.

 

-Jeff

 

I didn't know that, really all this time I had been using my old book Compute's book on machine language, they have a conversion list, I just am too lazy to figure each number out the way I explained I do some times. lol

Some times I will if it is something easy like 37, 32+4+1 easy but most of the time I get my book! lol

 

So I thought there must be a conversion tool to do it automatically out there so I found that web site just a few moments ago.

 

Thanks

Wade

[Pac Munchkin]

In case you'd like to know, I have a Hexadecimal / Decimal / Binary / Octal / Quintal / Ternary Converter on this page:

 

http://www.randomterrain.com/atari-2600-me...tools-toys.html

 

I was just looking at the great job you did on your color chart! Wow at a glance I can see all the colors in decimal value without loading up ColourTest.bin and cycling through the colors to find what I am looking for.

 

http://www.randomterrain.com/atari-2600-me...html#colorchart

 

 

Great Job!!!!!!

 

Wade