02/37/84 hasp_host_ Syntax for attach description: hasp_host_ -control_args Function: The hasp_host_ I/O module simulates record-oriented I/O to a single device of a workstation while communicating with a host system using the HASP communications protocol. See "Notes" below. Entry points in this module are not called directly by users; rather, the module is accessed through the I/O system. This I/O module must be attached to a subchannel of a communications channel configured to use the HASP ring-0 multiplexer. See the description of the HASP multiplexer in MAM Communications. This I/O module is designed primarily for use by the Multics I/O daemon. Control arguments: The following control arguments are optional, with the exception of -comm, -device, and -tty: -comm hasp is required for compatibility with other I/O modules used by the I/O daemon. -ebcdic is accepted for compatibility with other I/O modules used by the I/O daemon, but is ignored by this I/O module. -device STR specifies the type of device for this attachment. STR must be one of teleprinter, reader, printer, or punch. The type specified by this control argument must match the type of device attached to the channel name defined below. -physical_line_length N, -pll N is accepted for compatibility with other I/O modules used by the I/O daemon, but is ignored by this I/O module. -terminal_type STR, -ttp STR is optional and is used to define the character set used by the remote system. STR must be the name of a terminal type defined in the site's terminal type table (TTT). See "Character set specification" below. -tty channel_name specifies the communications channel to be attached. The channel must be a subchannel of a HASP multiplexed channel (e.g., a.h014.prt3). Open operation: The hasp_host_ I/O module supports the sequential_input, sequential_output, and sequential_input_output opening modes. Write record operation: The write_record entry converts the supplied data record from ASCII to the remote system's character set, performs data compression, and transmits the record to the HASP multiplexer. The structure and the referenced constants supplied to this I/O module are contained in the terminal_io_record.incl.pl1 include file. Read record operation: The read_record entry returns a single record from the device, basically performing the inverse of the functions described for the write_record operation. Additionally, for line printer attachments, the carriage control information in the record is converted into the appropriate slew information in the terminal_io_record. The structure and the referenced constants that this I/O module returns in the supplied buffer are contained in the terminal_io_record include file. Modes operation: This module accepts the non_edited and default modes for compatibility with other I/O modules used by the I/O daemon, but ignores them. List of control operations: This I/O module supports the following control operations: end_write_mode ensures that all previously written data has been transmitted to the HASP multiplexer and then writes an end-of-file record for the device. hangup_proc is used to specify a procedure to be invoked when this attachment's channel is hung up. read_status determines whether or not there are any records waiting for a process to read. resetread discards any pending input. resetwrite discards any as-yet unprocessed output. runout ensures that all data has been transmitted to the HASP multiplexer from where it is guaranteed to be transmitted to the terminal. select_device and reset are ignored rather than rejected for compatibility with other I/O modules used by the I/O daemon. signon_record supplies a SIGNON record for transmission to the remote system. The info_ptr must locate the signon_record_info structure, which is declared in the include file hasp_signon_record_info.incl.pl1. See "Notes on SIGNON processing" below. no_signon_record validates that the multiplexer is not configured to send a SIGNON record to the remote system. See "Notes on SIGNON processing" below. Notes on SIGNON processing: Before communicating with certain remote systems, Multics must send the SIGNON record. This specially formatted record identifies Multics to the remote system. For these systems, the Multics multiplexer must be configured to use signon_mode (see MAM Communications). Before data transmission is permitted, the signon_record control order must be issued on an I/O switch attached to the operator's console subchannel of the multiplexer. If the remote system does not expect a SIGNON record, the no_signon_record control order can be used to validate that the multiplexer channel is properly configured. Character set specification: This I/O module allows the specification of the character set used by the remote system through the -terminal_type attach option. If -terminal_type is given, the referenced terminal type must be defined in the site's TTT with an input and an output translation table. This module uses these translation tables to convert data from the remote system's character set to ASCII and vice versa. If -terminal_type is not given, the remote system is assumed to use EBCDIC. In this case, the subroutine ascii_to_ebcdic_ is used to convert data sent to the system; the subroutine ebcdic_to_ascii_ is used to convert data received from the remote system. Notes: As stated above, this I/O module is used to simulate the operation of a single device of a HASP workstation. If the simulated device is a card reader, the caller supplies records to this module that are then formatted and transmitted to the remote host; in other words, a card reader attachment through this switch is an output-only attachment. Similarly, this I/O module receives records from the remote host when the simulated device is either a line printer or a card punch. Thus, line printers and card punches attached through this I/O module are input-only devices. Special I/O daemon software is provided to allow Multics to simulate the operations of a workstation in order to submit jobs to remote systems and receive those jobs' output print and punch files. This workstation simulator uses this I/O module for communications with the remote host. ----------------------------------------------------------- Historical Background This edition of the Multics software materials and documentation is provided and donated to Massachusetts Institute of Technology by Group BULL including BULL HN Information Systems Inc. as a contribution to computer science knowledge. This donation is made also to give evidence of the common contributions of Massachusetts Institute of Technology, Bell Laboratories, General Electric, Honeywell Information Systems Inc., Honeywell BULL Inc., Groupe BULL and BULL HN Information Systems Inc. to the development of this operating system. Multics development was initiated by Massachusetts Institute of Technology Project MAC (1963-1970), renamed the MIT Laboratory for Computer Science and Artificial Intelligence in the mid 1970s, under the leadership of Professor Fernando Jose Corbato. Users consider that Multics provided the best software architecture for managing computer hardware properly and for executing programs. Many subsequent operating systems incorporated Multics principles. Multics was distributed in 1975 to 2000 by Group Bull in Europe , and in the U.S. by Bull HN Information Systems Inc., as successor in interest by change in name only to Honeywell Bull Inc. and Honeywell Information Systems Inc. . ----------------------------------------------------------- Permission to use, copy, modify, and distribute these programs and their documentation for any purpose and without fee is hereby granted,provided that the below copyright notice and historical background appear in all copies and that both the copyright notice and historical background and this permission notice appear in supporting documentation, and that the names of MIT, HIS, BULL or BULL HN not be used in advertising or publicity pertaining to distribution of the programs without specific prior written permission. Copyright 1972 by Massachusetts Institute of Technology and Honeywell Information Systems Inc. Copyright 2006 by BULL HN Information Systems Inc. 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