./_Man_NeXT_html/html4/np.4.html

Manual page for NP(4)

np - NeXT Laser Printer interface

SYNOPSIS -- Kernel Configuration

device np0 at bus? csr 0x0200f000

SYNOPSIS -- Programmatic Interface

#include <sys/ioctl.h>
#include <bsd/dev/npio.h>

DESCRIPTION

The NeXT Laser Printer is a 300/400 DPI high-speed, non-impact (low noise) printer based on electrophotography and laser technology. It is based on the Canon LBP-SX series laser printer engine. The printer also can be selected to feed automatically from a paper cartridge or manually. Print rates can go as high as eight pages per minute.

The device driver allows a NeXT Laser Printer to be attached to /dev/np0. Upon opening /dev/np0 the printer is powered on and initialized to 400 DPI and cassette feeding. Only one task can have the printer open at a time. The printer can only be opened with the O_WRONLY flag. The O_NDELAY flag will cause the open to return before the printer has completed the power on and initialize cycle. The following error codes are returned by open:

ENODEV: There is no printer connected to the printer port.
EIO: An IO error in initializing the printer.

Please note that with O_NDELAY set, you will not get power on, or initialization errors reported. All subsequent ioctl and write operations other than power on/off requests will fail with the EPWROFF error. The correct way to determine when the open has completed the power on and initialization is to select for write and exceptional conditions. If the open fails for some reason, the printer will be left in the powered off state.

The printer interface supports the FNDELAY file descriptor status flag. When this flag is set, all operations that would block will instead return the EWOULDBLOCK error code. The printer interface also supports the FASYNC file descriptor status flag. When this flag is set, the write operation will return at once instead of waiting for the page to complete.

A number of additional ioctl operations are available on the printer interface. The following definitions are from <sys/npio.h>

/*
 * Structures and definitions for NeXT Laser Printer io control commands
 */

/* Paper types */
enum np_papersize { NOCASSETTE, A4, LETTER, B5, LEGAL };

#define	NPIOCPOP	_IOWR('p', 1, struct npop) /* do a printer op */

/* Structure for NPIOCPOP - printer op command */
struct npop {
	short	np_op;		/* operations defined below */
	union {
		int	        	npd_power;     	/* Power */
		unsigned char	npd_resolution;	/* 300/400 DPI */
		struct {
			int	left;	/* # of bits to indent on left */
			int	top;  	/* # of lines from top of page */
				/*
				 * NOTE: less than a 200 line top margin
				 * 	is questionable.  Experiment.
				 */
			int	width;	/* width in #'s of longwords  */
			int	height;	/* height in lines */
		}		npd_margins;
		struct np_stat {
			u_int	flags;
			u_int	retrans;
		}		npd_status;
		enum np_papersize	npd_size;
		boolean_t		npd_bool;
	} np_Data;
};
#define np_power     	np_Data.npd_power
#define np_margins   	np_Data.npd_margins
#define np_resolution	np_Data.npd_resolution
#define np_status    	np_Data.npd_status
#define np_size      	np_Data.npd_size
#define np_bool      	np_Data.npd_bool

/* Operations */
#define NPSETPOWER     	0  /* turn the printer on/off */
#define NPSETMARGINS   	1  /* Set the printer margins */
#define NPSETRESOLUTION	2  /* Set the printer resolution */
#define NPGETSTATUS    	3  /* Get the printer status */
#define NPCLEARRETRANS 	4  /* Clear the retransmit counter */
#define NPGETPAPERSIZE 	5  /* Get the paper size */
#define NPSETMANUALFEED	6  /* Set manual feed based on npop.np_bool */

/* Resolutions */
#define DPI300         	0
#define DPI400         	1

/* Status bits */
#define NPPAPERDELIVERY	0x0001  /* Paper is being processed in printer */
#define NPDATARETRANS  	0x0002  /* Data should be retransmitted due to jam
						      or poor video signal.  Number of pages
						      is in npop.np_stat.retrans.  Clear this
						      with the NPCLEARRETRANS command. */
#define NPCOLD     		0x0004  /* Fixing assembly not yet hot enough */
#define NPNOCARTRIDGE  	0x0008  /* No cartridge in printer */
#define NPNOPAPER      	0x0010  /* No paper in printer */
#define NPPAPERJAM     	0x0020  /* Paper jam */
#define NPDOOROPEN     	0x0040  /* Door open */
#define NPNOTONER      	0x0080  /* Toner low */
#define NPHARDWAREBAD  	0x0100  /* Hardware failure */
#define NPMANUALFEED   	0x0200  /* Manual feed selected */

Images consist of a bitmap of the pixels to put on the page. A 1 in the bitmap will cause a black mark to be placed on the page, and a 0 will leave a pixel white. The page has four margin parameters: left (the number of pixels to indent on the left hand side); top (the number of lines to come down from the top of the page); width (the width of the image in numbers of 32-bit longwords); and height (the number of lines in the image).

To print a page, you first need to set the image margins for the page with the NPSETMARGINS printer command. Then you submit the image with the write command. The image data must be page aligned at the beginning, and must be quadword (increments of four longwords) aligned at the end.

ERROR CONDITIONS

The printer can be in one of four states -- off, ready, printing, or error. The write operation and all NPIOCPOP commands except NPSETOP will return EPWROFF if the printer is powered off. The write operation the NPGETPAPERSIZE and the NPSETMANUALFEED commands may block waiting for the printer to be in the ready state unless the FNDELAY flag has been set, in which case, they will return EWOULDBLOCK if the printer is printing and EDEVERR if the printer is in the error state.

More error information about the printer can be retrieved with the NPGETSTATUS command.

Other error codes that may be returned include:

ENOINIT: The margins were not set before write was called.
EDEVERR: The printer is in the error state.
ENXIO: Unknown NPIOCPOP command.
ENXIO: Unknown minor device number on open.
EIO: I/O error talking to printer.
EBUSY: Printer is already open.

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