Riso HC5500 Series Reference Manual page 27

Long edge binding
Even more convenient ways of printing are possible by combin-
ing duplex printing with the Booklet (Pagination) function.
For example, 4 single-sided
pages (4 x A4)
In case of paper jam during duplex printing...
During printing, paper travels at high speed inside the
printer. For this reason, not only the jammed paper but
also the ones in motion should be removed.
This is especially true for the duplex transfer unit, which
may contain several papers. When paper jam occurs
during duplex printing, rotate dial B inside the printer
until all the paper is removed.
For your reference, a seal showing instructions related
to paper jam becomes visible by opening the front
cover of the printer.
See User's Manual for Printer Main Body page 3-9.
Short edge binding
You can print on one A3 sheet
(stapling is unnecessary)
Duplex Transfer Unit
Dial B
US/UK-25