Device independence relieves the programmer of concern for device characteristics and allows a single FP to serve a range of different terminal types. A single FP can communicate with a variety of terminal types, using the same form and procedure.
The CP-6 forms processing system ensures that the various terminal features of differing types of terminals are used to the fullest extent possible. For example, for a video screen terminal, the forms processing system will adapt communication so that all constants are displayed at once, cursor repositioning occurs, and terminal features such as character validation are utilized; for an interactive teleprinter, the forms processing system sees that the constants are displayed field-by-field to suit the line-by-line operation characteristics of the teleprinter, that validation of each field is performed, and that any invalid entries are resolicited in a manner suited to the particular device.
CE26-02_DRAFT Device Independence
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Transaction Processing Features
The TP environment provides the structure and protection necessary for efficient on-line transaction processing. In addition, the CP-6 Transaction Processing offer these important features:
• Full CP-6 capabilities. The TP environment permits the TPAPs and TP system to make use of all available CP-6 services. For instance, file management and security is performed in the same way as in other CP-6 environments.
• Data base integrity. The 1-0-5/11 Data Base Manager can playa critical role in the TP environment. 1-0-5/11 detects and corrects deadlock on file accesses. 1-0-5/11 also creates transient journals and allows TPAPs to checkpoint file data for backup in case file recovery is required.
• Automatic recovery/restart. The TP system in conjunction with 1-0-5/11 provides an option for automatic data base roll-back and re-run of transactions which caused data base updates during system recovery (e.g., after a "soft" failure).
• Debug facilities. The system debugger, DELTA, is available to debug TPAPs in the TP mode as well as all other modes of access. In addition, a special test mode is available in TP for protection of the data base during debug sessions.
• Instance and administration. A person designated as the Instance administration. A administrator of an instance of TP controls operations of its application(
s).
The administrator provides on-line control including:11-4
Privacy and security. Safeguards centralized at the host provide authorization checks for TP operators and permit discretionary system surveillance.
Auto-logon. Special purpose TP stations such as stand-alone. printers can be logged on automatically.
Accounting. The TP system makes special provisions to account for TPAP processing time. Options are available to account for each transaction or for a series of transactions.
Transaction processing timing. Options are available to control the invocation of TPAPs. For example, a TPAP can be invoked to process either one transaction at a time or a series of transactions. Transactions of a specified type may optionally be bypassed and processed later.
Performance evaluation and tuning. Statistics collected for each instance of TP are available to the instance administrator who may alter operating characteristics to enhance performance.
Features CE26-02_DRAFT
Section 12 CP-6 Time-Sharing
The CP-6 system features a terminal "personality" that is designed to increase programmer productivity by creating a natural and powerful time-sharing environment. Access to all types of peripheral devices and rapid terminal response creates an atmosphere in which each time-sharing user appears to have the entire system dedicated to his or her tasks. Dynamic timing algorithms make the CP-6 system compatible with a wide variety of terminal types. The CP-6 system also provides utility processors that aid in accomplishing:
•
Program Development.•
Program Compilation.•
Program Execution.•
Program Debugging.•
File rv1aintenance.•
Text Creation and Editing.Overview
Programs to be executed via entry through the other access modes of operation may be completely or partially developed in the time-sharing mode. Since there is one common CP-6 file management facility. files used in the interactive mode are identical to those of the batch and real-time modes.
The command language (I B EX) by which the terminal user directs the course of a time-sharing session is identical to that used for a batch job (either local or remote).
Up to 500 time-sharing terminals may be simultaneously active. Under the CP-6 system, terminals can be connected to the system via dial-up communication lines or permanent circuit lines. These lines may be interfaced either locally or remotely, as described in section 9, CP-6 Communications Management.
Regardless of how a terminal is physically connected to the CP-6 system, terminal protocol is the same. After connection has been established, users identify themselves by entering log-on data: their account, their name, and (if required) a password. If the identification is valid and consistent with information maintained by the monitor, the user's on-line session is initiated
CE26-02_DRAFT Overview
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CP-6 Time-Sharing
and the system prompts the user for commands. If the identification is invalid. the CP-6 system sends an error message and requests the user to resupply the log-on data.
An on-line session is terminated by entering a simple command to log off. The CP-6 system then transmits selected accounting information and offers the user the opportunity to log on again. Thus, separate accounting for separate functions may be achieved by a change of account number and / or name.