BARR/3270 emulates a 3274 controller with a multiple-session DFT terminal attached. The product provides extensive support for various terminal types and printers, supports high communications speeds, and is easy to use.
BARR/3270 emulates both LU1 and LU3 type printers and can direct print output to printer, disk file, or screen. The software, like a controller, can have several host-connected printer sessions.
BARR/3270 has been used with a variety of printers. Print speeds on single and multiple printers range from 30 characters-per-second to beyond 20,000 lines-per-minute (lpm). Even the fastest laser printers are driven at maximum efficiency from a PC.
With BARR/3270, your PC can emulate a 3287 printer either as an LU1 or an LU3 type printer. Multiple printer sessions can be defined. You also have the ability to direct output from a printer session to a selected physical printer.
BARR’s 3270 display terminal support has a number of unique features, including true Model 3, 4, and 5 support with popular video adapters and other features useful to 3270 programmers and end-users.
The software emulates 3278 and 3279 terminals with different screen sizes (Models 2, 3, 4, 5). Screen size can vary from 24-43 lines and 80-132 columns.
Although the 25x80 screen for Model 2 terminals is standard, BARR products allow you to use larger screen sizes on many adapters:
IBM EGA
IBM VGA
Everex/EV-659 (EGA)
Tseng EVA/480 (EGA)
Paradise/VGA
VGA Wonder
US Video VGA
Genoa SVGA/6300
DTB VGA EM-16
Tecmar VGA-AD
If you are using one of the non-CGA adapters listed above, you can view a 33x80 screen on Model 3 terminals, and a 44x80 screen on Model 4 terminals. The 28x132 screen size for Model 5 terminals is supported by an IBM VGA adapter with a multiscan monitor, all non-IBM VGA adapters, and the Everex EGA adapter.
On most adapters, an 8x12 character set is used in 132-column mode to enhance readability. Adapters that do not allow true Model 3, 4, and 5 support feature horizontal scrolling, vertical scrolling, and fast scrolling (panning 10 characters at a time).
BARR/3270 changes the screen size automatically when requested by the host application program or when you hot key between sessions with different screen sizes.
Although most DOS applications use the 25x80 screen size, you can specify larger screen sizes for your DOS session (e.g., 43x80 or 28x132) during installation. DOS version 4.01 supports larger screen sizes. See Section 5.6 for details on specifying screen size and selecting other monitor and adapter options.
BARR/3270’s Reveal option shows the attributes of a 3270 field displayed on the screen at the cursor position. It also displays all null locations in the 3270 buffer, a feature useful to 3270 programmers for verifying screen images.
BARR software lets you capture screen images to a disk file. The Screen Save feature captures selected individual screens. The Record Screen feature captures a series of consecutive screens displayed during a session. Captured screen images can be printed and used in a variety of ways.
On-line Help displays information on key maps, cursor and scroll keys, and how to exit the program. You can activate On-line Help from any point in a 3270 session by pressing Ctrl+F2. On-line Help is also a menu for selecting 3270 functions.
BARR/3270 supports most popular keyboards. An On-line Keyboard Map facility eliminates the need for keyboard templates. Extensive support for international keyboards is also provided.
BARR/3270 supports the keyboards listed below:
IBM PC XT
IBM 83/84 Keys (AT)
IBM Enhanced 101/102 Keys
IBM 3270 PC
Key Tronic KB3270/PC
IRMA 3270
DCA IRMAKey
IBM Foreign 102 Key
You can alter the BARR/3270 initial keyboard map during installation with the Keyboard Map Editor. The editor is interactive, easy to use, and allows you to assign many PC key combinations to the same 3270 key.
BARR/3270 supports the international keyboards listed below. BARR software has a Keyboard Training Utility that takes only minutes to learn the correspondence between the key scan codes and their printable legends as defined by the DOS KEYB utility. This implementation guarantees truly universal support for all international keyboards.
International keyboards supported are:
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Belgian |
Norwegian |
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Canadian French |
Portuguese |
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Danish |
Spanish |
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Dutch |
Swedish |
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French |
Swiss |
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German |
U.K. English |
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Italian |
U.S. English |
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Latin American |
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You can use an FT-156 light pen to enter data with BARR/3270 and an adapter with light pen support. The Cursor Select function, indicated on the Help screen as Cursor Sel, emulates a light pen on a keyboard.
Many features simplify and extend the uses of BARR/3270—making it easy to learn and simple to operate.
The software is menu-driven. BARR/3270 shows you what to do at each stage. Operator instructions, prompts, and messages appear whenever you need to know about special conditions or make decisions. Introductory menus lead you into the program. You need only position your cursor and press ENTER to select an option or proceed to a new screen.
With BARR/3270 you can have a DOS session and up to four simultaneous 3270 sessions. You can switch to a particular session by entering a hot-key combination or by selecting the session from a Sessions menu.
If you have a color monitor adapter, BARR/3270 uses the color attribute to increase the readability of messages on the screen.
BARR/3270 automatically allocates memory. At the beginning, the program determines how much memory is available and automatically assigns free memory space for buffers. It also automatically determines whether the monochrome or color monitor adapter is present as well as the numbers and addresses of parallel and serial ports.
Device assignments are specified in the Installation Description (described in Chapter 5). Once this process is complete, BARR/3270 automatically performs Logon operations and readies all devices at power-on of the PC.
BARR/3270 can instruct the modem to dial the host computer automatically. You can even have the autodial begin late at night when telephone rates are low. The dialing instructions are entered on a menu and permanently stored in the program. The BARR PC-SYNC series of dial-up synchronous internal modems for PC and PS/2 MCA operate at 2400, 4800, or 9600 bps. These modems conform to the standards: Bell 201C, Bell 208AB, CCITT V.22, CCITT V.29, CCITT V.32, and UDS 9600.
The Logon line is entered in the Installation Description and does not need to be re-entered with each communication with the host. BARR/3270 automatically sends the Logon line for you.
BARR/3270 supports the popular IND$FILE Send and Receive protocols in TSO, CMS, and CICS environments.
With BARR/3270 you can perform file transfers in either foreground or background. For example, you can transfer a file in a 3270 session while you are working interactively in another 3270 or DOS session. You can also perform file transfers from several 3270 sessions simultaneously.
BARR/3270 uses many techniques to maximize the speed of file transfers. These include the Write Structured Field (WSF) version of IND$FILE, support for large inbound data packet sizes, and a sophisticated queue scheduler that assures close to 100% line utilization.
BARR/3270 transmits data at high speeds on both dial-up and dedicated lines. Data can be sent and received simultaneously. All data will be transmitted, converted, or translated as necessary. Statistics displayed on the screen provide information on the current status of communications.
Superior software architecture is the essence of BARR/3270. With the BARR multi-tasking operating system, all tasks operate concurrently: entering commands, receiving console messages from the host, printing on several printers, reading from disk, reading from a serial port, and sending or receiving from the synchronous line.
BARR/3270 communicates via an RS232/V.24, V.35, or X.21 connector to a synchronous modem. Speeds from 1200 to 19,200 bps are achieved on the PC, PC XT, and PS/2 models 25 and 30. The PC AT and PS/2 Micro Channel models can communicate up to 384,000 bps.
The BARR/3270 Token Ring version links to the mainframe via a direct Token Ring connection and operates at either 4,000,000 or 16,000,000 bps. The mainframe connection to the Token Ring Network is through the Token Ring Interface Coupler (TIC) installed in the 3725, 3745, or 3174 controllers. The PC connection to the Token Ring is through the IBM, 3-COM, or other compatible Token Ring adapters.
BARR/3270 operates at full-duplex. Files are sent and received simultaneously, and throughput increases by 100% compared to half-duplex. Most other SNA products are half-duplex, even though dedicated lines and some dial-up modems (for example, V.32) are full-duplex.
Although you may think of your task as transferring files in only one direction, responses need to flow in the other direction as well. With half-duplex, receiving must pause while responses are sent. With full-duplex, responses can be sent without delay. This can increase throughput by 5-15%.
On a satellite link line, turnaround delays are two-thirds of a second due to the speed-of-light. Full-duplex eliminates line-turnaround delays and may increase throughput as much as 150%.
VTAM uses the DATMODE=FULL to specify full duplex.
Satellite communications require radio waves to travel 54,000 miles from earth to the satellite and back. Since the speed of light is 186,000 miles per second, a .8 second delay is introduced between sending a frame of data and receiving an acknowledgment that it was received.
BARR/3270 supports both modulo 8 and 128 SDLC counts. Modulo 8, the standard for other packages, can send only seven frames past the most recently acknowledged frame; in other words, only seven frames can be sent until an acknowledgment is required. Modulo 128, available in BARR/3270, removes this barrier. Seven frames will not fill the .6 second satellite delay; however, BARR/3270 can exceed seven frames using modulo 128.
BARR/3270 works equally well on a dial-up or dedicated line. When communicating by dial-up line, messages on the screen advise you of the appropriate time to make the telephone connection.
BARR/3270 maintains statistics on the number of blocks sent and received, as well as the number of communication errors encountered.
Built-in diagnostic tools and comprehensive implementation of 3270 messages help end users and support personnel resolve problems quickly.
The BARR/3270 Operations screen displays error messages related to the PC environment in self-explanatory text, eliminating the need for you to reference an error message number. 3270 error messages, which use IBM’s DFT error message numbers, are displayed in the session’s Operator Information Area (OIA), the last line of your 3270 screen.
Lines 1 and 2 of the screen display detailed information about the communications activity and current status of all devices. You will be able to read and interpret all of the information easily.
The Communication Scope is a unique feature of the BARR/3270 product. It contains the type of blocks sent and received by the last 40 communications events.
It has a function similar to a communications line monitor. Most low-level communication problems are resolved by examining the Communication Scope.
The status line advises you of the condition of printers, disks, and serial ports.
The loopback testing program is an important installation and maintenance tool that verifies the correct operation of the BARR synchronous adapter, cable, and modem connection.
Barr Systems, Inc. provides a toll-free customer support number for answers to hardware or software questions related to its products. Call 800-BARR-SYS (800-227-7797) or 352-491-3100 from 9:00 a.m. to 8:00 p.m. Eastern time. To facilitate problem resolution, have the serial number of the Barr communications adapter on hand when you place a call for support.
BARR/3270 can be extended with optional add-on products for specialized applications. These products are integrated with the operation of BARR/3270 for user convenience.
The BARR/GATE product distributes the SNA mainframe connection to any PC on a Local Area Network (LAN). BARR/3270 can be run on any PC, including the BARR/GATE gateway PC, without additional hardware.
Barr’s PRINT370 product drives S/370 channel-attached printers at their maximum speeds from a PC or PS/2. An S/370 channel emulator adapter is installed in the PC along with BARR/3270. Up to six S/370 channel-attached printers are attached to the adapter by a Bus and Tag cable.
Printers presently supported include Bull Series 3000; Xerox 4050, 4090, 8790, and 9790; IBM 3203, 3211, 4245, 4248, and 6262; Kodak Komstar; NCR COM; Siemens 2050; and STC 5000 Series.
The Dataproducts interface, which originated with the Dataproducts Corporation, is used for driving high-speed printers and typesetting equipment. Barr offers BARR/DPI and BARR/DPI2 adapters for attaching a PC or PS/2 to a printer with the Dataproducts interface.
Since BARR/DPI appears to the PC as a parallel printer adapter (LPT1, LPT2, LPT3), all software used with these ports will function with BARR/DPI. It is completely compatible with BIOS and DOS.