3770Link

text regarding the status of the connection. You should see the following text in each LU window during the connection process:

Activating Link To The Host ...

PU Is Active

LU Is Active => SSCP-LU Session Established

Sending Formatted Logon (INIT_SELF)

Session Bound

LU-LU Session Established

In addition, each LU window has a status bar which displays the current connection state of the LU. The status will change from Disconnected, to System and finally to User as the connection completes.

When the connection completes, you will see the following welcome message in the console window:

LOGON TO DEMO HOST SUCCESSFUL

SIMULATED DOWNLOAD FROM HOST

WILL BEGIN IN 5 SECONDS.

After 5 seconds, the first configured LU (RJELU1) will begin to receive a printer file from the host, and the following text will be displayed in the RJELU1 window:

Printer Active ...

Receiving To: PRINTER.001

Output Redirected By JOBNAME Field To: JOBNAME.001

During the simulated download, the first pane of the status bar of the RJELU1 window will display Printer Active, and the second pane will display the number of records received.

When the simulated download completes, you should see the following message in the RJELU1 window:

Receive Complete, 131 Records Received

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IBM 3770 manual Receive Complete, 131 Records Received

3770 specifications

The IBM 3770, introduced in the mid-1970s, was a pioneering multi-user data station known for its innovative design and functionality, aimed primarily at supporting online transaction processing. As one of the early efforts in integrating computers with communication technology, the 3770 set a foundation for subsequent advancements in the field.

One of the standout features of the IBM 3770 was its ability to support multiple user connections simultaneously. This multi-user capability allowed organizations to connect various terminals to a central computer, facilitating efficient data entry and retrieval processes. Each terminal could communicate with the mainframe, enabling users to access real-time data and execute transactions concurrently, which was revolutionary for its time.

The 3770 utilized a proprietary communication protocol that leveraged synchronous serial communication, ensuring reliable data transmission over telephone lines and enabling the automation of remote data entry. This technology reduced the need for physical interaction with centralized data processing systems, leading to increased productivity and efficiency in organizational workflows.

In terms of characteristics, the IBM 3770 was equipped with a dedicated processor for handling input and output operations. This feature offloaded routine tasks from the mainframe, optimizing overall performance and freeing up computational resources for more intensive processing activities. Additionally, the system was designed to support a variety of input devices, including keyboards and card readers, accommodating different user preferences and operational needs.

The architecture of the IBM 3770 included a unique data format that streamlined the handling of transactions. This format allowed for easy integration with existing databases and applications, making it an attractive solution for businesses looking to modernize their data processing capabilities. The system also featured built-in error detection and correction routines, which ensured data integrity during transmission.

Moreover, the IBM 3770 was recognized for its flexibility and scalability. Organizations could easily expand their networks by adding more terminals or connecting additional mainframe storage. This scalability was crucial for businesses experiencing growth, as it eliminated the need for frequent system overhauls.

In summary, the IBM 3770 was more than just a data station; it was a significant step forward in online transaction processing, combining innovative communication technologies with multi-user functionality. Its features, such as dedicated processing, support for various input devices, and scalability, set the stage for future advancements in data systems and remain influential in shaping the landscape of computing.