Hi,
I assume you connected all the cables back properly.
The first thing you should do is checking if you fried your harddisk or not.
You might connect it your PC (no hotswapping) and boot your pc with a floppy to dos. Use the ATAPWD program to find out if your disk is locked or not. If it is broken, there is a change that the bios of your pc will complain about the disk. You might put the harddisk jumper on the master position instead of the cable select position.
If ATAPWD can't access your harddisk, you fried it and you will need a new one.
You will need your Eeprom contents of your Xbox. You can get these on 2 ways:
1. With a modchip. The harddisk of another xbox will only work if it is unlocked and if your xbox doesn't differ to much in version. (A 1.1 disk will not work in a 1.6 xbox due to differences in the design.
2. With a xbox Eeprom reader. There are tutorials on the web how you can build one. Some of them (with only a couple of resistors and zeners) will not work on every Pc. It all depends on the voltage levels your Pc serial port accepts as valid levels.
3. Once you have your Eeprom.bin file of your xbox, you can use the xboxHDM program to partition a new harddisk you can use in your xbox. With the Crazy Ndure Installer, you can softmod it the same time. You can lock it so that you can use it without modchip.
I don't see any other options in your case.
If you are really unlucky, you might have damaged your xbox ide port. In that case, forget about all the above writings.
regards.