Chapter 1. Host Connection Program Overview

The Host Connection Program is a 3270 connectivity application for the AIX environment. The Host Connection Program (HCON) emulates a subset of 327X functions and features, and it allows end users at AIX terminals to connect to an IBM System/370 host and appear to the host as an attached IBM 3270 Display Terminal or printer. HCON facilitates file transfers between the workstation and the IBM System/370 host, allows printer emulation, and provides High-Level Language Application Programming Interface (HLLAPI) support for user-provided workstation applications to communicate with 3270 sessions.

HCON connectivity can be:

• System Network Architecture (SNA) connection in a Type 2.1 low-entry networking (LEN) node attachment
• Distributed Function Terminal (DFT) SNA attachment to an IBM 3274/3174 or IBM 9370 Workstation Subsystem Controller
• Transmission Control Protocol/Internet Protocol (TCP/IP) Telnet 3270 connection
• DFT Non-SNA attachment to a 5088/6098 Graphics Control Unit.

The SNA Node T2.1 and TCP/IP capability can operate over a wide area network (WAN), allowing users at a remote work group location access to the services and facilities of an IBM System/370 or System/390 Host. This protocol also supports the IBM Token-Ring or Ethernet network, which allows users to access these same services and facilities over a local area network (LAN). The coax DFT attachment uses the 3274/3174 in both SNA and non-SNA mode and supports up to five sessions per IBM 3270 Connection Adapter.

The HCON Connectivity figure illustrates the connectivity capability of HCON.

HCON Capabilities

The HCON 3270 emulation program:

• Provides IBM 3278/79 display emulation support on ASCII terminals, including the IBM 3151, IBM 3161, IBM 3162, IBM 3163, IBM 3164, DEC VT100, DEC VT220, WYSE WY-50, WYSE WY-60 and WYSE WY-370.
• Supports multiple host sessions within a single AIX terminal using AIXwindow support.
• Provides features using the AIX window interface, including menu bar support and light-pen simulation using a mouse. These features require the (X11R5) with Motif version 1.2.
• Supports the 3278/79 Models 2, 3, 4, and 5. Models 3, 4, and 5 are only available on aixterm sessions, Xstations, or xhcon run in AIXwindows. Model 5 is also available on the IBM 3151 with Expansion Cartridge.
• Supports the IBM 3286/87 printer emulation.
• Supports DFT connection through the 3270 Connection Adapter. The mainframe system console attachment using DFT is also supported. Each model can support up to four adapters, and each adapter can have up to five active sessions for the following interfaces:
  • 3174 or 3274 Control unit
  • 4361 Workstation adapter
  • 9370 Workstation subsystem controller
• Supports up to 16 sessions by connecting to the IBM 5088 Graphics Channel Controller or 6098 Channel Control Unit through the System/370 Host Interface Adapter.
• Permits more than one active session per user up to a maximum of 26 per user. (The total number of user sessions cannot exceed the number of sessions available through the hardware interface connections.)
• Provides extended data stream support for seven colors plus either reverse video, underlining, or blink. The actual attribute displayed depends on the capabilities of the display.
• Grants file transfer:
  • Support for queued or immediate file transfer requests
  • Support for C and FORTRAN programming interface to file transfer
• Supports industry-standard HLLAPI support using C, FORTRAN, and COBOL languages:
  • Workstation-application control of emulation session in an operatorless environment
  • Workstation-application control of keystrokes in an operatorless environment
• Provides utility session support where the frequently used utilities are centralized. HCON allows:
  • Color redefinition
  • Keyboard redefinition
  • Session logon and logoff automatically with generation of session logon/logoff scripts
  • File transfer support implicitly or explicitly
• Enables a user to interact with HCON on either a local or remote X server, or remotely by using TCP/IP, Telnet, or remote login. When running remotely, the user must be aware that host connection functions are executed on the "connected-to" system. The display emulation functions are viewed where the user's terminal is running, but other host connection functions can run and affect files (by file transfer) and facilities (such as printers) on the "connected-to" system rather than the local system.
• Provides support for the SNA Logical Unit (LU) pooling to improve LU resource management and administration by:
  • Monitoring a specific LU pool during peak hours to help ensure fair distribution
  • Aiding to identify congested pools and low-usage pools
  • Displaying the status of each LU for session management and host problem determination

HCON's features and connectivity capabilities are detailed in Chapter 2 "Using Host Connection Program".

National Language Support

This program includes National Language Support (NLS) for both single-byte character set (SBCS) and double-byte character set (DBCS). Actual SBCS character presentation on ASCII display terminals may be limited by a particular display terminal's capability, and the use of international names can be restricted in the customization of color and keyboard mapping.

NLS overall characteristics include:

• International Language Support (ILS) for all SBCS countries currently supported by AIX Japanese, Korean and Traditional Chinese language support using DBCS.
• Multiple sessions in different national languages are concurrently supported with some restrictions.
• Message handling is supported by these programs by providing messages, panels, and prompts that can be translated. The translatable material is separated from the program executable code.

The Japanese Language Support program characteristics includes support for the:

• IBM 3270 kanji display emulation support on the Xstation. Multiple host sessions are supported within a single AIX terminal or across multiple virtual terminals on the high-function terminal (HFT). Kanji display sessions only can operate on an aixterm within the AIXwindows environment, supporting kanji input and output operations, or the PS/55 with DEC VT100 interface using an ASCII terminal. The PS/55 requires both of the following:
  • Nihongo DOS Version K3.3 and up
  • Nihongo Procomm 4500-JCK or 5605-JCK.
• 3278/79 Models 2, 3, 4, and 5.
  • IBM 3270 kanji printer emulation on printers with the capability to handle DBCS and field outlining.
• IBM 3270 kanji stream.
• DBCS-Asia Query Reply and the Character Sets Query Reply Character set IDs and code page IDs for Japanese Language Support, including the following:
  • Japanese katakana-SBCS (CS-CP: 332-290)
  • DBCS (370-300)
  • Japanese English-SBCS (101-037)
  • DBCS (370-300)
  • Operator-controlled single- or double-byte editing using Shift-in Shift-out (SI/SO) through a special key sequence.
• Expanded extended data stream for field outlining capability.
• Alternate Viewing Mode allowing users to switch the displaying character set between Japanese katakana and Japanese English by a local key operation.
  • Kanji character input by using the DBCS Input Method and Kana-Kanji Conversion (KKC) function provided by the AIX Version 3.
• File transfer with additional file transfer command option flags for Japanese host file transfer program support. These option flags are not supported for C and FORTRAN programming interfaces.

The High-Level Language Application Program Interface (HLLAPI) does have DBCS language support.

Machine Requirements

The following are fixed-disk storage requirements for the AIX 3270 Host Connection Program licensed program:

Memory and fixed-disk requirements for other licensed programs, user applications, and data are not included in the above. Carefully review all system, memory, and fixed-disk requirements with your marketing representative.

HCON also runs on the following ASCII terminals using 3278/79 Model 2 emulation or Model 5 on IBM 3151 using the expansion cartridge (these terminals cannot be used for DBCS language support):

• IBM 3151
• IBM 3161
• IBM 3162
• IBM 3163
• IBM 3164
• DEC VT100
• DEC VT200
• WYSE WY-50
• WYSE WY-60
• WYSE WY-370

HCON provides National Language Support for 3151 and 3164 terminals using ISO8859-1.2 code set. The support can be provided using the appropriate NLS cartridge.

HCON supports IBM 3286/87 printer emulation with printers that use PC-ASCII data stream. HCON also supports IBM 3270 DBCS printer emulation for the following printers with the capability to handle DBCS character and field outlining:

• IBM 5572-B02
• IBM 5575-B02/F02/H02
• IBM 5577-B02/F02/G02/H02
• IBM 5579-H02
• IBM 5587-G01/H01
• IBM 5327-011
• IBM 4208-502
• IBM 4216-510
• IBM 4019

  Note: The enhanced functions of the IBM 5587 printer are not supported.

Connection Requirements

Interfaces for connection to a System/390 can be one or more of the following network communication adapters:

• For coaxial attachment, the IBM 3270 Connection Adapter (#2990) (22F0189) with appropriate cables for attachment to:
  • an IBM 3174/3274 Control Unit
  • an IBM 4361 Workstation Adapter
  • an IBM 9370 Workstation Subsystem Controller configured for distributed function terminal mode.
• For coaxial attachment, the IBM System/370 Host Interface Adapter with appropriate cables for attachment to an IBM 5088/6098 Graphics Control Unit.

Both SNA and non-SNA are supported.

• For SNA Node T2.1 attachment, display and printer LU types 1, 2, and 3 are supported. (AIX SNA Services is a prerequisite.)
  • 4-Port Multiprotocol Communications Controller (30F8813) for attachment to a WAN. Physical interface type is RS232D/V.24, V.35, and X.21.
  • Single-port Multiprotocol Adapter/2.
  • X.25 Interface Co-Processor/2 Adapter providing support for attachment to X.25 packet-switched data network. The supported physical interfaces are X.21 and X.21 bis (V.24, V.35).
  • Token-Ring High-Performance Network Adapter.
  • Ethernet High Performance LAN Adapter.
• For TCP/IP attachment using the Telnet 3270 function, the following are supported:
  • Token-Ring High-Performance Network Adapter
  • Ethernet High-Performance LAN Adapter
  • X.25 Interface Co-Processor/2
  • Fiber Distributed Data Interface (FDDI) Connectivity
  • Block Multiplexer Channel Connectivity
  • ESCON Channel Connectivity
  • Serial Optical Channel Converter Adapter

Users at a remote location may access the services and facilities of a System/390 host. Depending on the network topology and controller requirements, the connection to the System/390 host may be as follows:

• SNA T2.1 for LU types 1, 2, and 3 with the following prerequisite for the SNA Services licensed program:
  • LAN (Token-Ring or Ethernet) and WAN (X.25 and SDLC) access using 37X5 or 3174 communication controllers.
• DFT coaxial connection when attaching to a 3X74 or the equivalent:
  • For SNA mode, display session (LU type 2) is supported.
  • For non-SNA mode, both display and host-addressable printer sessions are supported.
• TCP/IP connection for display session using the Telnet 3270 option:
  • LAN (Token-Ring, IEEE802.3, Ethernet, and IBM Fiber Distributed Data Interface (FDDI) Connectivity) access using the appropriate 8232 or 3172 Interconnect Controller
  • WAN (X.25) access using the 37X5 controller
  • Direct attachment using the Block Multiplexer Channel Connectivity or the ESCON Channel Connectivity
  • Serial Optical Channel Converter attaching to an NSC DX router hyperchannel attachment to a System/370 processor

Programming Requirements

HCON requires AIX (5756-030) and runs on the POWERstations. HCON requires one of the following System/390 operating system environments:

• VM/SP CMS
• VM/XA CMS
• MVS/SP TSO/E
• MVS/XA TSO/E
• CICS/VSE
• CICS/MVS
• VSE/SP Version 4
• VSE/ESA Version 1.3

For SNA T2.1 connection to the host, VTAM Version 3.2 or above is recommended.

HCON requires one of the following programs be installed on the System/370 or System/390 host to support file transfer:

• System/370 or System/390 Host-Support File Transfer Program (IND$FILE) for Virtual Machine/Conversational Monitor System (VM/CMS) (5664-281).
• CICS/VS 3270 PC File Transfer Program (5798-DQH) is required for CICS/VSE, CICS/MVS, CICS/ESA and CICS/MVS/ESA. For VSE/SP and VSE/ESA, no prerequisite programs are needed. All required programs are part of the base VSE operating system support.
• Host-Support File Transfer Program (IND$FILE) for Multiple Virtual Systems/Time Sharing Option (MVS/TSO (5665-311).

At least one of the following programs must be installed on the System/370 or System/390 host to support file transfer for files that consist of SBCS or DBCS text:

• VM/CMS File Transfer Program Version 1.1 (5799-BWK)
• VM/CMS File Transfer Program Version 2.1 (5799-PGX) MVS/TSO File Transfer Program Version 1.1 (5799-BWJ)
• MVS/TSO File Transfer Program Version 2.1 (5799-PGY)
• CICS (MVS/VSE) File Transfer Program Version 1.1 (5799-BWL)
• CICS (MVS/VSE) File Transfer Program Version 2.1 (5799-PGZ)

Limitations

HCON does not support the following 3270 functions:

• Security keylock
• Magnetic reader control and accessories
• Monocase switch
• Video output
• APL/text character set
• Programmed symbols
• Alternate cursor
• Cursor blink
• Explicit partitions
• Numeric lock
• Response time monitor for an IBM 3174 or 3274 Control Unit
• Control Unit printing support for 3287-attached printers by using the PRINT key