Memory and Storage
Memory was a significant limitation of the ST55, with no card slot for expansion. The phone could store up to 255 contacts in its phonebook and kept track of call records with 10 dialed, 20 received, and 20 missed calls. For media, it had 1.2 MB allocated to store photos, which might seem restrictive, but for quick snaps and essential contact storage, it sufficed in that era.