The UAS400 (UAS/400) is a small-sized computer system which can also be used as
multi-user computer systems. By this, we mean that a single computer can interact with more than
one user at a time. The ‘UAS’ stands for “Unofficial Application System” and was introduced by the
Unofficial Aptiva Support site, aptivasupport.com in 2022.
The UAS400 can be utilized for different web facets. Some models are designed as systems that
provide resources to other computers, also known as a “server” in a network of computers,
while others are set up for use with terminals or “display stations”.
ARPA-OS/90 is the operating system for the UAS/400. It is a Layered Architecture mainly used for
Web Applications. ARPA-OS/90 is a POSIX compliant, Internet-centric Environment for your Web Applications.
ARPA-OS/90 is more than an Operating System, with it's built in Database Environment and modern architecture.
Innovation comes in many forms, and one of our goals was to do more with less. We had to be creative and
open minded. UAS/400 is a Scalable, Modern and Cost-effective Application System.
* Disclaimer: UAS/400 is not affiliated to IBM or IBM AS/400 computer system in any way.
UAS is short for Unofficial Application System, and 400 is refering to the HTTP 400 Bad Request response status.