Rich's Tongfamily (Richtong.net add-on)

2.5″ to 3.5″ Hard Drive Adapter – FLT-3120. In building Grace’s new minicomputer, one thing I forgot was something that will take a 2.5″ notebook drive and let you fit it into a 3.5″ slot. Here’s one from google. These are actually hard to find.
The standards are different, not only is the drive smaller, but it uses a 40 pin connector vs. a 44 pin IDE and a separate power Molex power connector.