HP T5730 TeemTalk 6.0 for Windows User Manual - Page 223

Setup Menus SO/SI XTN SO/SI XLT Factory default: Unchecked The setting of these options determine the effect of the ESC SO and ESC SI sequences when receiving or transmitting data. When receiving from the host, the setting of the SO/SI XTN option determines whether the sequences are used to switch between standard and extended character sets (checked), or reverse highlight and underline (unchecked). When transmitting to the host, the setting of both options determine the sequences used for switching between standard and extended character sets, and reverse highlight and underline as follows: XTN XLT SO SI Extended Characters Reverse Video Underline Sent as Sent as Begin End OFF OFF ON OFF OFF ON ON ON SO ESC'. ESC'. ESC'. SI ESC'/ ESC'/ ESC'/ ESC SO SO ESC SO SO ESC SI SI ESC SI SI The SO (shift out) and SI (shift in) sequences allow switching between two sets of characters: the standard character set and the extended character set. Each set consists of 128 characters. When an ESC SO sequence is received from the host, the emulation displays all subsequent characters from the extended character set until an ESC SI sequence is received to switch back to the normal character set. The Unisys T27 emulation transmits an ESC SO sequence when it encounters extended characters in its display buffer and an ESC SI when standard characters are to be sent. There is no automatic shift in (ESC SI) at the end of a data transmission block. Unisys T27 Settings 201