Breather Hole

Like all other hard drives, the Toshiba MK1234GSX comes with a breather hole. In this case, it's located at the top left corner of the PCB. Yeah, the breather hole on this drive is located at the bottom of the drive.

The breather hole allows condensation inside the hard drive to escape as well as equalizes the hard drive's internal pressure with the ambient pressure. So, please make sure you do NOT occlude the hole when you install the hard drive!

Jumpers And Connectors

At the end of the PCB are the SATA interface and jumper block (second picture above, from left to right). Since most notebooks only have a single hard drive bay, there's usually no need to change it from the default setting of Master (no jumper installed).

But should you need to reconfigure this hard drive, you can do so using the four pin jumper block. Of course, you will need to consult Toshiba's documentation and use your own jumper, since the drive doesn't come with a jumper.

Total Capacity

The Toshiba MK1234GSX hard drive has a total capacity of 120,031,477,760 bytes.

That just barely meets its rated capacity of 120GB, where 1GB is calculated as 1,000,000,000 bytes.

After formatting it in NTFS, only 119,960,240,128 bytes were available. About 71MB was lost to formatting.