"devdump" - Browsing Raw Data from CD

<< ISO 9660 Standard for Data CD

<< Herong's Tutorial Notes on CD/DVD

This section describes a tutorial on how to browse raw data from a CD-ROM with devdump.

Another very useful tool in the "cdrtools" package is called "devdump", which allows you to browse raw data on the CD interactively. "devdump" supports 4 commands below:

• b - Display the next 256 bytes on the screen.
• a - Display the previous 256 bytes on the screen.
• g xx - Go to the given section and display the first 256 bytes.
• q - Quit the command.

Here is what I did to display the first 256 bytes of the Primary Volume Descriptor.

1. Start the command "devdump dev=0,0,0". The first 256 bytes of the first sector is displayed on the command window:

0000000000000000 00000000 00000000 00000000 00000000 ................
0000000000000010 00000000 00000000 00000000 00000000 ................
0000000000000020 00000000 00000000 00000000 00000000 ................
0000000000000030 00000000 00000000 00000000 00000000 ................
0000000000000040 00000000 00000000 00000000 00000000 ................
0000000000000050 00000000 00000000 00000000 00000000 ................
0000000000000060 00000000 00000000 00000000 00000000 ................
0000000000000070 00000000 00000000 00000000 00000000 ................
0000000000000080 00000000 00000000 00000000 00000000 ................
0000000000000090 00000000 00000000 00000000 00000000 ................
00000000000000a0 00000000 00000000 00000000 00000000 ................
00000000000000b0 00000000 00000000 00000000 00000000 ................
00000000000000c0 00000000 00000000 00000000 00000000 ................
00000000000000d0 00000000 00000000 00000000 00000000 ................
00000000000000e0 00000000 00000000 00000000 00000000 ................
00000000000000f0 00000000 00000000 00000000 00000000 ................

 Zone, zone offset:              0 000000000000

2. Enter "g 10". The first 256 bytes of the Primary Volume Descriptor sector 16 (or 0x10) is displayed:

0000000000008000 20202020 20202020 00013130 30444301 .CD001..
0000000000008010 20202020 20202020 20202020 20202020
0000000000008020 20202020 5f5f5f5f 20202020 20202020         ____
0000000000008030 20202020 20202020 20202020 20202020
0000000000008040 00000000 00000000 20202020 20202020         ........
0000000000008050 00000000 00000000 0a810000 0000810a ................
0000000000008060 00000000 00000000 00000000 00000000 ................
0000000000008070 01000001 01000001 00000000 00000000 ................
0000000000008080 0000002e 0c010000 0000010c 00080800 ................
0000000000008090 00130022 00000000 2f000000 00000000 ......./...."...
00000000000080a0 036b0008 00000000 08001300 00000000 ..............k.
00000000000080b0 20200001 01000001 00000220 001c110c .... .........
00000000000080c0 20202020 20202020 20202020 20202020
00000000000080d0 20202020 20202020 20202020 20202020
00000000000080e0 20202020 20202020 20202020 20202020
00000000000080f0 20202020 20202020 20202020 20202020

 Zone, zone offset:             10 000000000000

Note that the displayed HEX values should be read from right to left. So the first byte is 0x01 and the second byte is 0x43 in the above display.

Sections in This Chapter

CD Track Types - CD-ROM Modes

ISO 9660 Standard - File System for CD-ROM

cdrtools - ISO 9660 Command Line Tools

isoinfo - ISO 9660 Command Line Tools

"isoinfo -l" - List of Files and Their Locations

"readcd" - Read Raw Data From CD

"devdump" - Browsing Raw Data from CD