IBM 4400 User Manual

Edit Mode

Any printable character in the data stream can replace printable characters or
spaces already loaded in the print buffer. The space character (hex 20) is
used to skip characters in the print buffer that are not to be replaced and,
similar to underlining or deleting, the new characters are inserted in the
appropriate positions. Table 13 illustrates the edit mode. Note that the editing
function replaces characters; it cannot be used to print the same character
twice (double strike) in the same location. Use the DEL code (hex 7F) to make
a character blank.

NOTE: In order for edit mode to work correctly, the protocol must be

configured for a carriage return only. If configured for a carriage
return and a line feed, the contents of the buffer are printed upon
receipt of the CR code, disabling the editing function.

NUL Code

NUL (hex 00) is ignored by the printer and can be used as a fill character;
however, it can not be used to add blank spaces since it is not a space
character.

Table 13. CR Edit Mode Example

Enter in Print Buffer

Printed Result

Example 1

AAABBBCCC

(CR)

SSSSDSSSB

(LF)

AAABDBCCB

Example 2

ABCDEF

(CR)

______

(CR)

ABCDEF

Key:

S = Space (hex 20);
LF = Line Feed (hex 0A);
CR = Carriage Return (hex 0D)