The 1300 is LIDL. It cannot print characters natively so the only setting that will work with it is Raster.
The 932 is PCL3 so it should work with all 3 settings (depends of course on what the unix machine is putting out).
If the 932 is directly connected, direct is the best setting. It shoud work on normal though as well.
The LJ 5 is PCL6. It should work with all 3 settings too but as with the 932, direct would probably work best.
Some serial boards like the equinox interleave the printing output with the screen output. This IS in effect multiple jobs. These multiport boards expected printers to be connected directly to the back of terminals. They have no concept of a windows style print job. The closest to this terminal style behavior in ICE is the direct setting. The other two settings use the windows spooler and as such the settings for the spooler involving form feeds, print while transfering, job timeouts, etc will affect what you get for output.