Pathway/iTS TCP and Terminal Programming Guide

Programming for Specific Terminals

Compaq NonStop™ Pathway/iTS TCP and Terminal Programming Guide—426751-001

3-3

Positioning the Screen Fields

All fields must reserve a blank character position immediately before the field.

For example:

•

If a single-character field is to be located at line 2, column 2, on the terminal screen,

then both character positions 2,1 and 2,2 must be reserved for that field. In that

case, a second field could not begin at character position 2,3 on the terminal screen

because the preceding character position (2,2) is already in use by the preceding

field and is therefore no longer available as a blank character position.

•

A field cannot be at character position 1,1 because the character position preceding

1,1 does not exist and thus cannot be reserved.

The minimum separation, in bytes, between screen elements for the IBM 3270 is

indicated in Table 3-2

Positioning the Cursor

Cursor positioning on screens with protected fields after an ACCEPT operation acts

differently on an IBM 3270 than such cursor positioning does on a 6520. The IBM

3270 does not prevent cursor positioning at a protected field. The 6520, however,

automatically repositions a cursor to the next unprotected field if the cursor initially

positions at a protected field. If you do not want the cursor to be positioned at a

protected field on an IBM 3270 before an ACCEPT operation, you can use the SET

command to specify NEW-CURSOR at the desired, unprotected screen field.

Table 3-2. Minimum Character Separation for IBM 3270 Terminals

Second Element

First Element Field Literal Overlay Area End of Screen

Start of base screen 1 1 0* N. A.

Start of overlay screen

occupying area that does not

have the same width as its

base screen **

110 N. A.

Field 1 (3)*** 1 0 (1)****

(2)***

0 (2)***

Literal 1 1 0 (1)**** 0

Overlay Area 1 1 0 0*

* Does not support WHEN FULL TAB.

** When an overlay screen occupies an overlay area that does not have the same width as its base screen, an

overlay field cannot wrap from one line to the next.

*** Extra separation (two or three bytes) required to support WHEN FULL LOCK.

**** Extra separation required to support WHEN FULL TAB. Use one byte to separate the elements.