ZCOM Tables and Data Structures

Physical Terminal Tables

PTTYPE - Terminal type (physical)

Protocol module terminal type. It is initially setup by TTGEN in the memory image file but is subsequently maintainable.

SCFG_LEN - Length of the special protocol configuration bytes.

This field contains the length of any protocol specific configuration data contained in the spec_cfg[] field.

SPEC_CFG - Special protocol configuration data

This field contains any protocol specific configuration data that might be needed. The details on its contents and how to configure this field is documented in the protocol manuals.

PTUSER - User-maintainable area

This area extends to the end of the physical terminal table. It defines the area that may be modified by a zptup call, and contains all the following fields:

PTPOLL - Terminal poll addresses

PTSLCT - Terminal select addresses

These words usually contain the poll and select addresses specified for the terminal in the TTGEN configuration file. For some protocols however, they contain other configuration information. Specific content for these words is documented in protocol accessory manuals.

PTOPTN - Protocol options

Used to define options to the protocol module on the Mux interface card. Only bits 0 - 7 are relevant to the Mux. Bits 8 - 15 may contain other (host level) options. The definition of the bits depends on the protocol (PTTYPE) type.

PTVCNO - X.25 logical channel number

Used to contain status information - by x25cn & zx25d for X.25 terminals.

PTCNFG - Special configuration

For X.25, contains a call number.

Chapter 3

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