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IBM 3153 ASCII Terminal Display - Basic principles
Applicable to: World-Wide
The following are some principles of operation for an an ASCII terminal:
- Communications via a serial interface. Communications interface is RS-232, RS-422 and RS-423. The IBM 3153 does not support RS-423. Most (90-95%) ASCII terminals attach via RS-232.
RS-232:
- communicates up to distances of 75 feet.
- has a single transmit (TD) and receive data (RD) pin.
- has modem/communication control pins:
- Request to Send (RTS)
- Clear to Send (CTS)
- Data Set Ready (DSR)
- Carrier Detect (CD)
- Data Terminal Ready (DTR)
RS-422:
- communicates up to distances of 4000 feet.
- has two transmit (TD) and two receive data (RD) pins.
- does not have modem/communication control pins. If the RS232, RS422 communications cabling is incorrect, no communications occurs. The 3153 screen remains blank, and the cursor does not move.
3153 Serial Communications Ports:
- Main Port (SES1-EIA):
- RS-232 or RS-422 (based on the 3153 model).
- When RS-232 interface, configured as a DTE.
For a DTE:
Pin 2 (Transmit Data): Direction is out
Pin 3 (Receive Data): Direction is in
- Usage: Host (direct attach or modem) or serial printer
Auxiliary Port (SES2-AUX):
- Always RS-232 interface, configured as a DCE.
For a DCE:
Pin 2 (Transmit Data): Direction is in
Pin 3 (Receive Data): Direction is out
- Usage: Host (direct attach or modem) or serial printer
- Communication is asynchronous. The ASCII terminal and the host can communicate at the same time. In other words, the ASCII terminal and the host can transmit data simultaneously.
- Communication is typically in an ECHO environment. When the 3153 key is pressed, the 3153 transmits the character, ASCII sequence to the host. The host ECHO's back the character or processes the ASCII sequence. An ASCII sequence is usually sent as a result of a cursor key, insert key, delete key, function key being pressed.
- For a 3153 to communicate to a host, printer or modem, the 3153 and the host, printer and modem need to be configured for the same speed (baud rate), parity and word length. Also the communications cable also needs to be properly wired. If the cable is incorrectly wired and the communication values do not match, the 3153 will not communication or may display garbage, funny, graphics characters.
- After the proper cable is used, and communication values do match, the 3153 needs to be configured for the emulation that the host operating system or the host application expects. ASCII emulations include: IBM 3151, WYSE 50, WYSE 60, ADDS ViewPoint A2. ANSI emulations include: VT200, VT100. If the 3153 is configured for the proper emulation the application and keys should work properly. If the 3153 emulation is not the same as the host, alphanumeric characters will appear, but the application will be incorrectly displayed.
- After the emulation is correct, some 3153 setup values affect the display of the application. Items include: rows, columns, auto wrap. Some of the 3153 setup values affect the keyboard operation. Items include: New Line, Enter, Return, and Print keys.
Keywords: D/T3153 3153 General Info Information Principle Basic Communication Setup Emulation Keyboard Keys RS-232
RS-422 RS232 RS422 232 422 Modem Local Remote RS/6000 RS6000 AIX RISC UNIX
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Date Created |
26-08-97 | |
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Last Updated |
03-12-98 | |
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Revision Date |
17-11-99 | |
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Brand |
IBM Monitors | |
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Product Family |
Terminals | |
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Machine Type |
3153 | |
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Model |
Various | |
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