Unisys EFP9800 manual NCR 5021 Printer Emulation Commands Echo, Write Device Control Memory

NCR 5021 Printer Emulation Commands

Echo

When the printer receives this command, it takes the data following 1B 5B 7A vv yy, converts the data to unpacked ASCII, and returns the converted data to the host computer. This is useful when performing diagnostics on the printer.

This command is executed immediately, regardless of the state of the printer.

Hexadecimal		Decimal	ASCII
1B 5B 7A vv yy yy...yy 27 91 122 vv yy yy…yy			ESC ] z vv yy yy…yy
Value of vv	Value of yy
0-80H	0-FFH

The printer sends the following in reply to the message: 1BH, 5BH, vvH, vvH, yyH, ... yyH, 70H.

The value of vv is the number of bytes sent (in unpacked ASCII).

The value of yyyy...yy is the data sent in the ECHO message (in unpacked ASCII).

Write Device Control Memory

This command modifies the character set loaded in memory. Each character in the character set consists of seven 12-bit dot patterns.

Data that is forced outside the range of the character set by an incorrect address is ignored. There are 224 characters in the character set and each character consists of seven 12-bit patterns.

This command is processed only when the printer is offline.

The 5021 J/V printer’s character field is 9 dots wide and 7 dots high (9x7). When SPI 5021 prints a line, it automatically inserts space between characters equivalent to three dot positions which are inaccessible to the user. Countries that use the Arabic language require that this area be accessible. As a result, the 5021 RS-232C J/V printer implements a 12x7 character field and does not insert space between characters.

There are 224 characters in the printer’s character set. The range of hex values for the characters is 20-FF. Hexadecimal values in the range of 00-1F that are not control characters are printed as ASCII spaces (20).

8–8 3255 4073–002