I see three commands with three errors.
1. The MAKEDEV program is called in upper case: MAKEDEV, not makedev.
2. There should be no whitespace between sd and 1: sd1.
3. You selected the wrong partition. "c" is the physical disk drive, "i" is the filesystem.
These first two commands
must have generated errors. But you have not reported any.
Try these three commands. Pay attention to the commands you enter, and actually note any errors.
Code:
# cd /dev
# sh MAKEDEV sd1
# mount /dev/sd1i /mnt
If you get an error message from any of these commands, READ it.
If you get no error message, try
# ls /mnt
If you see files and directories you recognize from your USB device, you will now have finally successfully mounted the device. Now, you can reissue your dmesg(8) command, and route the output to a file on the device. Then, you can unmount it, and share the dmesg buffer with the world.