Using an external hard drive as extra storage as well as an external hard drive

Hi,

My internal hard drive is getting close to full and I have a back up hard drive that has a lot more memory. I am currently running time machine on this external hard drive, however, what would be ideal would be if I could have part of it for these Back ups and part of it for data that I don't want on my computer, for example I have tens of gigabytes of photos that I want to keep but don't need them on my computer and this would free up a lot of space for me.

I can't understand why I can't just add the files into my hard drive as if it was a USB stick. whenever I try to put files on it, it just comes up with a sign that says it isn't permitted.

I am using theWD my passport

Any ideas?

Many thanks

Bryn

You will need to partition the drive, this is simple if you want to destroy your old Time Machine back-up and start a new TM mack-up a fresh

However if you want to keep the TM back-up and have a new partition, you can achive this via terminal

Resize partitions on-the-fly | Utilities | Macworld