I have found a manual which is called the 'DRTS-11 Reference Manual' (Distributed Real Time System) and it talks about a pieces of software which is placed on top of RT-11. According to the description it optimized for I/O and uses 2 systems. One being the 'I/O processor', the other being the DRTS-11 system. The introduction reads : This document describes version V04.00 of the DRTS-11 multiprocessor operating system, and the Qnector processor link.' Apparently this software was made by 'Westfries Systems BV' and/or 'Viking Computer Corp.' Interesting bit is that this system does need one to logon to it and one can switch accounts. BTW, the manual is both the 'User guide', 'Admin guide', and 'Installation Guide'. Does this ring a bell to anyone? Ed -- Dit is een HTML vrije email / This is an HTML free email.