|Also known as||Primos, DOS(VM), Multics-in-a-Shoebox|
|First appearance||Jan 2008|
|Height||163 cm (5'4")|
|Eye color||Mint green|
|Rival(s)||Minicomputer-tans of the 70's and 80's|
|Latest release||unknown, circa early 1990's|
Developed in the 70s, and peaking at popularity in the mid 80s, PR1MOS was a minicomputer OS. PR1MOS shows a strong Multics influence; several former Multicians worked at Prime Computer, and the founder of Prime referred to PR1MOS as Multics-in-a-shoebox. While a contender as a mainline minicomputer operating system, PR1MOS lost favor to PCs in the early 90s.
PR1MOS-tan is shown as a somewhat mature woman, with short black hair and green eyes (the colors referencing PR1MOS's command line screen colors). She wears a simple yet elegant dress and short jacket, footless stockings and flat shoes, a strange blend of 1700s and 1980s fashion influences (the former being a nod to Multics-tan's grandiose style of dress). She also wears a PR1MOS armband on her left arm, a reference to DOS-tan's style of dress, as PR1MOS's original name was DOS.
Her attitude is demure and professional. She did not spend much time in the public spotlight, and doesn't seem to mind living in obscurity. She is much like Multics aside from being a minimalist, and in fact worships her in a way, seeing Multics as her spiritual ancestor.
She is very resourceful, adaptable, inventive, and practical. While initially sad that her company met its demise, she doesn't spend any emotion grieving over the loss of her company, since to her time spent grieving is time not spent resourcefully.