Hard Drives
The primary hard drive in the Terca M4 is a 2.5", 9.5mm height, Serial ATA (SATA) drive.
Slim SelectBay HDD Adapter
Toshiba sells a Slim SelectBay HDD Adapter (mfg part: PA3134U-1ETC, $44.10) which can be used to mount a IDE (PATA) notebook hard drive in the Slim SelectBay. The adapter requires a Toshiba Tecra 8100 caddie and connector (TOS8100) which can be obtained from New Mode Electronics for $37.00
Hard Drive Recovery
There is a Toshiba utility to recover your hard drive. You can use it to restore your hard drive to be the same as when it came from Toshiba. But the utility will NOT preserve your data, application settings, or applications that you installed, or any other changes that you made. A better recovery strategy is to peform regular backups of your system. The Toshiba Recovery Utility uses Symantec's Ghost to do it's job.
Primary Notebook Hard Drives
The following notebook hard drives are known to work in the primary hard drive spot on the Tecra M4:
Hard Drive Review
Here is a review of some latest 7200RPM drives:
http://www.techreport.com/reviews/2006q1/mobile-hdds/index.x?pg=15