X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?p=fceu.git;a=blobdiff_plain;f=out_gp2x%2Freadme_cheat.txt;fp=out_gp2x%2Freadme_cheat.txt;h=9d74a5d475c8971e2565a36e9a4803094448961a;hp=0000000000000000000000000000000000000000;hb=aa2dba92740d5aeab520ed493df9188505a4c3d7;hpb=5a2aa426410ad21d332ff75b58e7f4ed8459d86a diff --git a/out_gp2x/readme_cheat.txt b/out_gp2x/readme_cheat.txt new file mode 100644 index 0000000..9d74a5d --- /dev/null +++ b/out_gp2x/readme_cheat.txt @@ -0,0 +1,283 @@ + + + FCE Ultra Cheat Guide + +***** This file was obtained from ***** +http://mednafen.com/documentation/cheat.html + + +/Last updated November 12, 2003 +Valid as of FCE Ultra 0.97.4/ + +*Table of Contents:* + + * Introduction <#intro> + o Cheat Files <#cheatfiles> + * The Windows Interface <#windows> + o Cheat Search Interface <#windows-search> + * The Text Interface(TODO) + * Examples <#examples> + o "Mega Man 3" Windows Example <#examples-mm3> + o "Over Horizon" Text Interface Example <#examples-oh> + * Tips <#tips> + +------------------------------------------------------------------------ + + + Introduction + +FCE Ultra allows cheating by the periodic "patching" of arbitrary +addresses in the 6502's memory space with arbitrary values, as well as +read substitution. "Read substitution" is the method that would be used +on a real NES/Famicom, such as done by the Game Genie and Pro Action +Replay. It is required to support GG and PAR codes, but since it is +relatively slow when done in emulation, it is not the preferred method +when a RAM patch will suffice. Also, in FCE Ultra, read substitution +will not work properly with zero-page addressing modes(instructions that +operate on RAM at $0000 through $00FF). + +The RAM patches are all applied a short time before the emulated +vertical blanking period. This detail shouldn't concern most people, +though. However, this does mean that cheating with games that use +bank-switched RAM may be problematic. Fortunately, such games are not +very common(in relation to the total number of NES and Famicom games). + + + Cheat Files + +Cheats are stored in the "cheats" subdirectory under the base FCE Ultra +directory. The files are in a simple plain-text format. Each line +represents a one-byte memory patch. The format is as follows(text in +brackets [] represents optional parameters): + + [S][C][:]Address(hex):Value(hex):[Compare value:]Description + +Example: + + 040e:05:Infinite super power. + +A colon(:) near the beginning of the line is used to disable the cheat. +"S" denotes a cheat that is a read-substitute-style cheat(such as with +Game Genie cheats), and a "C" denotes that the cheat has a compare value. + +------------------------------------------------------------------------ + + + The Windows Interface + +All addresses listed in the cheats window are in unsigned 16-bit +hexadecimal format and all values in these windows are in an unsigned +8-bit decimal format(the range for values is 0 through 255). + +The cheats window contains the list of cheats for the currently loaded +game on the right side. Existing cheats can be selected, edited, and +updated using the "Update" button. + + + Cheat Search Interface + +The cheat search interface consists of several components: a list of +addresses and associated data for a search, several command buttons, and +the search parameters. + +Each entry in the list is in the format of: + + Address:Original Value:Current Value + +The address is the location in the 6502's address space, the original +value is the value that was stored at this address when the search was +reset, and the current value is the value that is currently stored at +that address. Selecting an item in this list will automatically cause +the "Address" field in the cheat information box on the right side of +the window to be updated with the selected address. + +The "Reset Search" button resets the search process; all valid addresses +are displayed in the cheat list and the data values at those addresses +noted. + +The "Do Search" buttons performs a search based on the search parameters +and removes any non-matching addresses from the address list. + +The "Set Original to Current" button sets the remembered original values +to the current values. It is like the "Reset Search" button, but it does +not affect which addresses are shown in the address list. This command +is especially useful when used in conjunction with the "O!=C" search +filter. + +The "Unhide Excluded" button shows all addresses that are excluded as a +result of any previous searches. It is like the "Reset Search" button +except that it does not affect the remembered original values. + +The numbers assigned the names "V1" and "V2" have different meanings +based on which filter is selected. A list of the names of the filters +and detailed information on what they do follows("original value" +corresponds to the value remembered for a given addres and "current +value" is the value currently at that address. Also, if a value is not +explicitly said to be shown under a certain condition, then it is +obviously excluded.): + +"O==V1 && C==V2": + + Show the address if the original value is equal to "V1" AND the + current value is equal to "V2". + +"O==V1 && |O-C|==V2": + + Show the address if the original value is equal to "V1" AND the + difference between the current value and the original value is equal + to "V2". + +"|O-C|==V2": + + Show the address if the difference between the current value and the + original value is equal to "V2". + +"O!=C": + + Show the address if the original value does not equal the current + value. + +The following cheat methods/filters automatically perform the function +of the "Set Original to Current" button after "Do Search" is pressed. + +"Value decreased." + + Show the address if the value has decreased. + +"Value increased." + + Show the address if the value has increased. + +------------------------------------------------------------------------ + + + Examples + + + "Mega Man 3" Windows Example + +This example will give Mega Man unlimited energy. Immediately after +entering the Top Man stage, make your way to the "Add Cheat" window. +Push "Reset Search". Go back to playing and move right until the first +enemy appears. Allow yourself to be hit twice. Each hit does "2" damage, +so you've lost 4 energy bars. Go to the "Add Cheat" window again and +select the third filter ("|O-C|==V2") and enter the value 4 next to +"V2". Then push "Do Search". + +Several addresses will appear in the address list. You can try to find +the address you want through trial and error, or you can narrow the +results down further. We will do the latter. + +Go back to playing MM3 and get hit one more time and make your way back +to the "Add Cheat" window. Your damage is now "6". You can probably see +which address that contains your life(it is 00A2). If not, change V2 to +6 and push "Do Search" again. This should leave only 00A2. + +Select that entry in the address list. Shift your attention to the "Add +Cheat" box to the right. Type in a meaningful name and the desired +value(156; it was the value when you had no damage, so it's safe to +assume it's the maximum value you can use). Push the "Add" button and a +new entry will appear in the cheats list. The cheat has been added. + + + "Over Horizon" Text Interface Example + +This example will give you infinite lives in the NTSC(Japanese) version +of "Over Horizon". + +Start a new game. Notice that when you press "Start" during gameplay, +the number of lives you have left is indicated. With no cheating, you +start with 3 lives(2 lives left). + +Activate the cheat interface immediately after starting a new game. +Select the "New Cheats" menu and "Reset Search". + +I'll assume that the number of lives left shown in the game is the same +number that's stored in RAM. Now, "Do Search". You're going to use the +first search filter. For V1, enter the value 2. For V2, enter the same +value. This, coupled with the fact that you just reset the search, will +allow you to search for a value "absolutely"(as opposed to changes in +the value). + +Now, "Show Results". When I did it, I received 11 results: + + 1) $0000:002:002 + 2) $001c:002:002 + 3) $001e:002:002 + 4) $009d:002:002 + 5) $00b9:002:002 + 6) $00e3:002:002 + 7) $0405:002:002 + 8) $0406:002:002 + 9) $0695:002:002 + 10) $07d5:002:002 + 11) $07f8:002:002 + +You really can't do much yet(unless you want to spend time doing trial +and error cheat additions). Return to the game. + +After losing a life, go back to the cheat interface, to the "New Cheats" +menu, and "Show Results". Here are my results: + + 1) $0000:002:002 + 2) $001c:002:002 + 3) $001e:002:002 + 4) $009d:002:002 + 5) $00b9:002:041 + 6) $00e3:002:002 + 7) $0405:002:001 + 8) $0406:002:002 + 9) $0695:002:002 + 10) $07d5:002:001 + 11) $07f8:002:002 + +Notice that two addresses seem to hold the number of lives($0405 and +$07d5). You can lose another life and go "Show Results" again, and you +should see that $07d5 is the address that holds the number of lives. + +Now that you know the address that holds the number of lives, you can +add a cheat. You can either type in the number from the cheat results +list corresponding to the address you want to add a cheat for, or you +can remember the address and select "Add Cheat" from the "New Cheats" +menu. Do the former. + +Now you will need to enter a name for the cheat. I suggest something +short, but descriptive. "Infinite lives" will work fine. Next, a prompt +for the address will show up. Since you selected an item from the list, +you can press enter to use the associated address($07d5). Next, you will +need to enter a value. It doesn't need to be large(in fact, it probably +shouldn't be; abnormally high numbers can cause some games to +misbehave). I suggest a value of 2. After this, you should get a prompt +that looks like this: + + Add cheat "Infinite lives" for address $07d5 with value 002?(Y/N)[N]: + +Answer "Y". You now have infinite lives. + +------------------------------------------------------------------------ + + + Tips + +Games store player information in many different ways. For example, if +you have "3" lives in Super Wacky Dodgeball 1989, the game might store +it in memory as 2, 3, or 4, or perhaps a different number all together. +Also, say that you have 69 life points out of 200 in Mole Mashers. The +game might store how many life points you have, or how much damage you +have taken. Relative value searches are very valuable because you +probably don't know the way that the game stores its player data. + +Some games, especially RPGs, deal with individual numbers greater than +8-bits in size. Most that I've seen seem to store the multiple-byte data +least significant byte(lower byte of number) first in memory, though +conceivably, it could be stored most significant byte first, or the +component bytes of the number could be non-contiguous, though the latter +is very unlikely. For example, say I have 5304 experience points in +Boring Quest for the Overused Plot Device. To split the number into two +eight bit decimal numbers, take 5304 %(modulus) 256. This will give a +number that is the lower 8 bits. Next, take 5304 / 256. The integral +component of your answer will be the upper 8 bits(or the next 8 bits, if +the number is or can be larger than 16 bits) of 5304. Now you will need +to search for these numbers. Fortunately, most(all?) RPGs seem to store +large numbers exactly as they are shown in the game. +