<Ok, so on my distribution disk if I boot it up it comes up as RT-11 V20B S
<but if I boot DXMNTFB.SYS it comes up RT-11 V20B FB. What's the difference
<Floating point?
Not floating point.
SJ is the single job monitor
FB is the forground background monitor
(spooling to printer is a good background task!
Lator versions will have:
BM batch monitor (for a batch based system)
XM extended memory monitor
Other possibilities are also possible via a build.
Allison