SCDTools

I have hinted at my SCDTools before in previous posts and even released a few scripts individually. The SCDTools is a combination of PERL scripts along with some shell scripts. Some of the most useful are creating a Sega CD data track, converting images to Sega VDP formats, converting Sega VDP formats to images, converting wave to PCM, and decoding/encoding Sega CD Cinepak. All the scripts I have made for Sega CD development are located at:

http://sourceforge.net/p/scdtools/

If you run each script you will get a full description of the script, but here is a (very) quick description of each script:

Code (Text):

1. scd68kdcleanup
2.   Kind of cleans up output from 68kd (68k disassembler)
3. scdasm
4.   Wrapper for your favorite assembler and favorite options
5. scdasmall
6.   Run asmx, asm68k, and SNASM68K and verify they have the same output
7. scdchecksum
8.   A specific tool to make a 16 bit checksum for all but first two bytes
9.   and put the 16 bit checksum at the first two bytes of the file.
10.   Used for a specific homebrew game.
11. scdcinepakencode
12.   Encode a cinepak file
13. scdcinepakencodeframe
14.   Encode the image data for a cinepak frame
15. scdget
16.   Retreive the iso for the Sega CD in your CD-ROM
17.   Uses dd program
18. scdhex
19.   Does a search and replace using hex strings (I used for Sonic CD hacking)
20. scdimg2tile
21.   Converts an image to Sega VDP data
22.   Uses Perl's Image::Magick library
23. scdimgvdppalette
24.   TODO work in progress
25. scdisofilefromoffset
26.   Determines the filename from which an ISO byte index corresponds to
27.   Uses isoinfo program
28. scdlittle2bigword
29.   I used this to convert cram part of savestate file the more convient endian
30. scdmake
31.   Used to make a Sega CD ISO
32. scdmoviedecode
33.   Used to decode a Cinepak for Sega file
34. scdtile2img
35.   Converts Sega VDP data to a PNG
36. scdupdatebinfile
37.   Takes a binary file and replaces it at a specified byte index in a file.
38.   Useful for overwriting data in an ISO file.
39. scdwav2pcm
40.   Converts a wav file to Sega CD PCM data
41. scdwrite
42.   Writes Sega CD files out to a CD-R

 

In the SCDMAKE.CF you can add "$ipassemble = 0;" and "$spassemble = 0;" to have scdmake not assemble the IP and SP. When you do this, you need to make sure your IP.BIN and SP.BIN are updated appropriately.

You mentioned in a PM that you wanted to use scdmake for Sonic CD. Here are the things needed to append to the SCDMAKE.CFG to be able to rebuild the Sonic CD.

Code (Text):

1. $ipassemble = 0;
2. $spassemble = 0;
3.  
4. # soniccd.isoinfo is the output of "isoinfo -l -I soniccd.iso"
5. $isoMatch = 'soniccd.isoinfo';
6. $isoMatchFileExtent = 0x17;
7.  
8. # SEGA CD DEV manual says fill unused file bytes with 0xFF
9. # but the Sega developed Sonic CD uses 0x00...
10. $fillUnusedFileWithZero = 1;

Here is the copy of the IP.BIN, SP.BIN, soniccd.isoinfo, and SCDMAKE.CFG I used to quickly rebuild Sonic CD. You also need to copy all of the files from the Sonic CD to the same directory. It will make an iso where the only differences are "useless" fields (such as file dates).
https://dl.dropbox.com/u/26821164/SONICCDSTUFF.ZIP

Note: Sonic CD requires some files to be in a specific file locations in the ISO which is why we need the $isoMatch support.

 

You need to update to the latest scdmake for $isoMatch to work with a file with a .isoinfo suffix. Sorry that I forgot to mention that.

IP is the initial program (used by the MAIN-CPU on the Genesis) and the SP is the system program (used by the SUB-CPU on the Sega CD). These are different for every game. To extract these for different CDs, you can now use the new scdextractipsp tool I just added to SCDTools!

Sample usage:

Code (Text):

1. > scdextractipsp Z80ACCESS.ISO
2. Making IP.BIN from ISO offset $00000784 with size $0000087C
3. Making SP.BIN from ISO offset $00001000 with size $00000800