Here is all the files needed for a genuine DSTT with YSMenu as your primary firmware and TTMenu as your secondary firmware.
Make sure you can view ALL file extensions on your PC. To do so in Windows, open 'My Computer', click 'Tools', 'Folder Options', 'View'. Make sure 'Hide extensions for known file types' is UNTICKED. Click 'OK'.
Step by step :
1. Download Unofficial DSTT 1.17a12 Firmware (fake-killer disabled) HERE. Extract DSTT firmware to the root of your SD card.
2. Open your SD card on your PC. Rename TTMenu.dat TO TTMenu.nds. It will become the secondary firmware.
3. Download YSMenu (Google yasu ysmenu (2nd link). Search (Ctrl+F) T_T to find the file) and download 2009/03/27 00:00?EZ3in1+ NOR. Extract YSMenu to a folder on your PC and open that folder.
4. Extract just TTMenu.dat from the DSTT firmware to your YSMenu folder on your PC.
5. Open YSMenu folder on your PC. Run ttextract.exe. It will create 2 files : ttdldi.dat and ttpatch.dat
6. Edit YSMenu.ini in the YSMenu folder on your PC. Place ; in front of the line LITERALS=LITERALS_JPN. Remove ; from LITERALS=LITERALS_ENG. Save file.
7. Copy YSMenu.nds from your YSMenu folder on your PC to the root of your SD card.
8. Open your SD card on your PC. Rename YSMenu.nds TO TTMenu.dat. It will become the primary firmware.
9. In your YSMenu folder on your PC, copy ttdldi.dat, ttpatch.dat and YSMenu.ini to the TTMenu folder on your SD card.
10. Download the latest extinfo.dat, infolib.dat, savlib.dat and usrcheat.dat here. Copy them to the TTMenu folder on your SD card.
11. OPTIONAL : If you would like to skin YSMenu, add YSMenu1.bmp and YSMenu2.bmp (both must be 256x192) to the TTMenu folder on your SD card.
When finished, this is the final file result :
If you want the opposite and TTMenu as your primary and YSMenu as your secondary :
1. Rename TTMenu.dat TO YSMenu.nds
2. Rename TTMenu.nds TO TTMenu.dat
Hope this comes in useful. I have kept it very basic.
Make sure you can view ALL file extensions on your PC. To do so in Windows, open 'My Computer', click 'Tools', 'Folder Options', 'View'. Make sure 'Hide extensions for known file types' is UNTICKED. Click 'OK'.
Step by step :
1. Download Unofficial DSTT 1.17a12 Firmware (fake-killer disabled) HERE. Extract DSTT firmware to the root of your SD card.
2. Open your SD card on your PC. Rename TTMenu.dat TO TTMenu.nds. It will become the secondary firmware.
3. Download YSMenu (Google yasu ysmenu (2nd link). Search (Ctrl+F) T_T to find the file) and download 2009/03/27 00:00?EZ3in1+ NOR. Extract YSMenu to a folder on your PC and open that folder.
4. Extract just TTMenu.dat from the DSTT firmware to your YSMenu folder on your PC.
5. Open YSMenu folder on your PC. Run ttextract.exe. It will create 2 files : ttdldi.dat and ttpatch.dat
6. Edit YSMenu.ini in the YSMenu folder on your PC. Place ; in front of the line LITERALS=LITERALS_JPN. Remove ; from LITERALS=LITERALS_ENG. Save file.
7. Copy YSMenu.nds from your YSMenu folder on your PC to the root of your SD card.
8. Open your SD card on your PC. Rename YSMenu.nds TO TTMenu.dat. It will become the primary firmware.
9. In your YSMenu folder on your PC, copy ttdldi.dat, ttpatch.dat and YSMenu.ini to the TTMenu folder on your SD card.
10. Download the latest extinfo.dat, infolib.dat, savlib.dat and usrcheat.dat here. Copy them to the TTMenu folder on your SD card.
11. OPTIONAL : If you would like to skin YSMenu, add YSMenu1.bmp and YSMenu2.bmp (both must be 256x192) to the TTMenu folder on your SD card.
When finished, this is the final file result :
If you want the opposite and TTMenu as your primary and YSMenu as your secondary :
1. Rename TTMenu.dat TO YSMenu.nds
2. Rename TTMenu.nds TO TTMenu.dat
Hope this comes in useful. I have kept it very basic.