SELCOPYi & 3270 Terminal Emulation Software


Most users today rarely connect to IBM Mainframe systems using actual hardware 3270 terminals but do so using emulated 3270 terminals running on a PC workstation. Many of these 3270 terminal emulation products contain features and functionality that exceed that of a standard hardware 3270 terminal and keyboard. This allows tailoring of the look and feel of the individual's IBM Mainframe environment.

SELCOPYi provides the user with a windowing environment within a 3270 session (i.e. supports multiple window display, window repositioning, resizing, maximising, etc.) As such, CBL has identified certain features offered by 3270 emulator packages that facilitate use of the SELCOPYi environment.

The following table identifies commercially available 3270 emulation software products that have been tested at CBL and their ability to support those features pertinent to usage of SELCOPYi. It does not, however, reflect the vast range of other facilities available in each product.

Macros Mouse
Microfocus Reflection Yes Yes Yes Yes Yes Yes No
Rocket Terminal Emulator
(Formerly BlueZone)
Yes Yes Yes Yes Yes Yes No
OpenText HostExplorer Yes Yes Yes Yes Yes Yes Yes
IBM Personal Communications Yes Yes Yes Yes Yes Yes No
Microfocus Rumba Yes            
Nexus Terminal Yes Yes No Yes Yes Yes No
SDI TN3270 Plus Yes Yes Yes Yes Yes Yes  
Tom Brennan Vista tn3270 Yes Yes Yes Yes Yes Yes Yes

Large Screen Sizes

TN3270 terminals, served by the host TELNET server, may reference VTAM LOGMODEs that support non-standard screen sizes (i.e. indicate that a read partition query is to be issued by a host application to determine the capabilities of the device.) Standard screen size LOGMODEs are often referred to as Model 2/3/4/5 terminals and correspond to actual hardware 3270 terminals. Comprehensive 3270 emulator support of IBM-DYNAMIC TN3270 terminals will allow the user to specify the desired 3270 screen size (rows x columns) e.g. 40 x 132, 62 x 160 (maximum supported by ISPF), 86 x 190, etc.

Starting SELCOPYi in a 3270 terminal of larger than standard dimensions allows the user to view more windows concurrently and to display more information within each window. Note that, when using terminals with large dimensions, it may be necessary to reduce the font size and/or increase the resolution of the display in order to view the entire emulated terminal within the physical display.

To take advantage of this facility, VTAM LOGMODEs that support non-standard screen sizes should be made available via the host TN3270 server. D4C32XX3 is an IBM supplied LOGMODE that matches this criteria and should already exist in your VTAMLIB. If not, update the VTAM source member ISTINCLM with a new, dynamic LOGMODE then re-assemble and Link Edit it. e.g.

    MODEENT LOGMODE=DYNAMICB,                  X
          FMPROF=X'02',                        X
          TSPROF=X'02',                        X
          PRIPROT=X'71',                       X
          SECPROT=X'40',                       X
          COMPROT=X'2000',                     X
          RUSIZES=X'0000',                     X

A TELNETDEVICE statement should then be included in the TN3270 server configuration. e.g.


More detailed information on setting up Large Screen Sizes can be found on the Planet MVS website at:

Keyboard Mapping

The 3270 keyboard may be configured so that specific actions (keyboard functions and 3270 emulator macros) can be mapped to any of the shift-states (Shift, Alt, Ctrl, etc.) of an individual key. This allows assigning actions to more meaningful key strokes e.g. in the editor where PF1 adds and PF13 deletes a line, Alt-A and Alt-D could be remapped to PF1 and PF13 respectively.

In addition, the limitation of only 24 PFKeys can be overcome by assigning meaningful key combinations to emulator macros that, by simulating keystrokes, automatically find the command line, type in the appropriate command and hit ENTER to issue it.

SELCOPYi supports many functions and REXX macros that may be utilised via keyboard shortcuts. The Keyboard Map column indicates the emulator's ability to assign keyboard functions to key strokes, whereas the Keyboard Macro column indicates specifically its ability to assign emulator macros to key strokes.

Mouse Mapping

Like the 3270 keyboard, the mouse buttons may be configured so that they perform specific actions. For example, F4 is widely used within SELCOPYi as a point-and-shoot action key, so the ability to set the mouse right-click to F4 becomes invaluable. CBL recommends use of Left click then Right click in quick succession to position the cursor and hit the action key. The Mouse Map column indicates whether the mouse buttons may be mapped.

Particularly useful in SELCOPYi is the ability to use the double-left click mouse button to position the cursor and action <Enter>. (In the case of some 3270 emulators, this may depend on support of a HOTSPOT facility. e.g. IBM PCOMM.) The Mouse Enter column indicates the emulator's ability to assign <Enter> to the mouse button left-double click.

A very nice feature is the ability to map the Mouse wheel to SELCOPYi scrolling commands. For example, MouseWheel-Up/Down issues F7/F8 to scroll up/down, Ctrl-MouseWheel-Up/Down issues F10/F11 to scroll left/right. Since SELCOPYi window borders and title bars also respond to these function keys, a dragging effect can be acheived in order to move and resize windows. The Mouse Wheel column indicates the emulator's ability to map the mouse wheel.


3270 emulator macros may be written or recorded to perform multiple functions and keystrokes supported by the emulator. Each macro uses a macro language that may be unique to the particular emulator package (though many emulators now also support standard Visual Basic script.) In most emulators, a macro file may be mapped to a particular key stroke on the 3270 keyboard. The names and descriptions of 3270 emulator macros, generated at CBL, and their recommended key assignments for use with SELCOPYi, are displayed below.

Macro Name Key Map Description
All Alt-9 Issues CBLe ALL command with no parameters to display excluded lines.
AltL Alt-L Issues CBLe MARK LINE command to mark the edge of a line block.
Bof Ctrl-F8 Issues CBLe BOTTOM/BACK/DOWN commands to display bottom lines of the edited text.
CcDate Ctrl-F3 Issues CBLe Macro CCDATE to output today's date (yyyy/mm/dd) at the cursor position.
CmdLine Alt-NumHome Positions cursors on the Command Line.
CmdTexte Alt-F4 Issues CBLe CMDTEXT command to execute a command on the focus line with action of '<' reversed.
CopyBlockAlt-C Issues CBLe COPY BLOCK command to copy a marked line or box block to the focus position.
CurAll Ctrl-A Creates CBLe ALL command at the command prompt with target string equal to text at the focus position.
CurHome Ctrl-NumHome Issues CBLe CURSOR HOME command to toggle cursor between command line and focus position.
CurScale Alt-S Issues CBLe Macro CURSCALE to produce a numeric scale at the focus position in the edited text.
DelWord Alt-W Deletes a blank delimitted token at or following the cursor position.
ECmx Alt-0 Issues SELCOPYi EDIT command to edit the default CMX file. (Specified on System.CmdText in CBLIINI.)
EditAdd Alt-A Issues CBLe SOS ADD command to add a blank line following the focus line.
EditDel Alt-D Issues CBLe SOS DELLINE command to delete the focus line.
EditDup Alt-2 Issues CBLe DUPLICATE command to duplicate the focus line.
EditSJ Alt-J Issues CBLe SPLITJOIN command to split the focus line or join the focus line with the one following.
Exclude Alt-X Issues CBLe SELECT command to exclude the focus line from the display view.
Fill Alt-F Creates CBLe FILL command at the command prompt ready to fill a marked block with text.
HdSub Alt-8 Issues CBLe Macro HD SUB to convert the focus line into a section sub-heading.
HiLo Alt-7 Issues CBLe Macro HILO to toggle highlighting of the focus line with triple asterisk.
ISPFSwaL Ctrl-F10 Issues SELCOPYi ISPF command to open the ISPF SWAP LIST. (Only applicable when running under ISPF.)
ISPFSwap Ctrl-F9 Issues SELCOPYi ISPF command to SWAP to alternate ISPF screen. (Only applicable when running under ISPF.)
LDiff Alt-= (equals)Issues CBLe Macro LDIFF to compare the current view with the next in the ring.
MakeCurr Ctrl-F6 Issues CBLe Macro MAKECURR to make the focus line the current line.
MinorDo Alt-F6 Issues CBLe Macro BLOCK DOWN MINOR to place focus on the next line containing double asterisk/equals.
MinorUp Alt-F5 Issues CBLe Macro BLOCK UP MINOR to place focus on the previous line containing double asterisk/equals.
Prev Alt-F9 Issues SELCOPYi MDIPREV command to place focus on the previous MDI window (e.g. edit view) in the ring.
Reset Alt-U Issues CBLe RESET command to reset a marked line or box block.
RetrieveFAlt-F12 Issues CBLe RETRIEVE + command to place previously issued commands at the command prompt.
Sv Ctrl-S Issues CBLe Macro SV to update timestamp and level in the header of the current file and save it to disk.
TagTog Ctrl-H Toggles highlighting of the focus line on and off. (Sets/unsets the LINEFLAG bit for tag.)
Tof Ctrl-F7 Issues CBLe -*/DOWN commands to display top lines of the edited text.
Trb Alt-T Issues CBLe Macro TRB to insert TRACE functions around a marked block in an edited REXX macro.
TrbOff Ctrl-T Issues CBLe Macro TRB OFF to remove TRACE functions inserted by a previous invocation of TRB.
WinMax Ctrl-+ (plus) Issues CBLe WINDOW MAXIMISE command to maximise the current edit view (CBLe child window.)
WinMaxFr Ctrl-Num+ Issues CBLe WINDOW MAXIMISE FRAME command to maximise the current CBLe parent window.
WinRes Ctrl-- (minus)Issues CBLe WINDOW RESTORE command to restore the current edit view (CBLe child window.)
WinResFr Ctrl-Num- Issues CBLe WINDOW RESTORE FRAME command to restore the current CBLe parent window.

3270 Emulator Configuration

SELCOPYi takes advantage of features provided by certain 3270 emulator software packages. Configuration files, including settings for large screen definition, keyboard/mouse mapping, keyboard macros, etc. as used at CBL, can be downloaded for the following emulators:

3270 Emulation Product Zip File Size Last Update
IBM Personal Communications (PC3270) 124,910 bytes 2014/02/03 11:57
Tom Brennan Vista tn3270 50,145 bytes 2012/02/16 16:51