Simplify the following text for a Grade 8 native English-speaking person.
Original: Palm OS ( also known as Garnet OS ) is a mobile operating system initially developed by Palm , Inc. for personal digital assistants ( PDAs ) in 1996 .
Simplified: Palm OS is an operating system that is made to work on small computer devices , mostly Personal Digital Assistants . Palm OS was first released in 1996 , when the Palm 1000 was released .