Dell Latitude D505 HDD Upgrade

I have a "vintage" Dell Latitude D505 with a standard 40 GB HDD.

I am interested in "upgrading" to an SSD. Searches on the Internet are frustrating. I have compared the connector between the ATA-100 and a SATA laptop I recently upgraded. Obviously no match. Size does not seem to be a problem...

I am looking for guidance where I can find something like a 500GB SSD that will work in my trusty D505.