The old printer init command
DATATYPE = RAW
(in conjunction with PASSTHROUGH mode) now prevents A-Shell from doing any special processing relating to the CR, LF, and FF control characters.
This may be necessary in order to embed raw graphics into print files, as may be needed with certain EPF (e.g. Zebra label printer) and PCL protocols.
Otherwise, even though PASSTHROUGH mode sounds like it "passes everything through", in reality, you still get conversion of isolated LF into CRLF, and it still identifies page breaks by FF (i.e. chr(12)), calling a standard GDI printing routine to inform the printer of the start of a page. The LF to CRLF conversion would obviously alter any graphic image, and the page break call may have had unknown results, depending on the driver.
