JPH02114315A - Printer device - Google Patents

Abstract

PURPOSE:To more inexpensively distribute a new printer control command after delivery by providing a printer device with a program storing memory and loading down an extended printer control program. CONSTITUTION:An interpreting program for interpreting an extended printer control command in the program storing memory 17 executes a corresponding command when the command exists, and at the time of absence, returns control to a printer control command interpreting routine consisting of two bytes or more stored in a ROM 15. Thereby, it is also possible to substitute an existing printer control command supplied to the ROM 15 in addition to the simple addition of a new control command. Consequently, an extended printer control program can be distributed by using an FED device included in a host or a communication line.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer device, and particularly to a printer device that receives print data and printer control commands from a host and executes printing.

[Conventional technology]

In the conventional printer device, as shown in FIG. 3, a CPU section 32 is composed of a microprocessor, a working RAM, etc., and executes a basic control program and a control command interpretation program on a ROM 35. The basic control program performs basic control and management of the device during initialization of the device at power-on and reset, and during failure diagnosis.The printer control command interpretation program performs print data and printer control commands received from the host interface 31. and refer to the font information in the font memory,
Expand the print image on the image memory 33 and I10
An appropriate print command is sent to the processor unit 36 to cause it to print. In devices where high speed is important, the I10 processor unit 36 is implemented by a plurality of slave microprocessors, but in devices where cost is important, it may be implemented by a program on the ROM 35. Since the command interpretation program is supplied in the ROM within the printer device, it is extremely difficult to extend or modify the printer control commands after the product is shipped.

FIG. 4 is a block diagram of a conventional printer device that facilitates expansion and modification of printer control commands after the product is shipped. A ROM cassette holder 38 is provided in the main body of the printer device, and a new printer control command interpretation program can be read by RO.
It is designed so that it can be supplied with three M cassettes. In this configuration example, printer control commands can be expanded and modified relatively easily by attaching and detaching the ROM cassette 39.

Similarly, a RAM card or a magnetic recording medium may be used instead of a ROM cassette.

, C Problems to be Solved by the Invention In the conventional printer shown in FIG. 1, it is extremely difficult to extend or modify the printer control commands after the product is shipped.

Therefore, when a new product with expanded printer control commands is introduced, the old product cannot deal with the expanded part, resulting in the problem that full compatibility of printer control commands cannot be achieved between the old and new products. There is a point.

In addition, the printer shown in Figure 4 can distribute new printer control commands using a ROM cassette, but the cost of the medium itself, such as the ROM cassette, cannot be ignored, making it unsuitable for mass distribution. There is.

Accordingly, an object of the present invention is to provide a printer device that allows new printer control commands to be distributed at a lower cost after the Brita device is shipped.

Means for Solving 1 Problem] According to the present invention, in a printer device that interprets print data and printer control commands received from a host and executes printing, a readable/writable program storage memory; program version number comparison means for comparing the version numbers of a program already stored in a storage memory and a program newly transmitted from the host; and when the version number is updated by a signal from the program version number comparison means. The present invention is characterized by comprising a printer control command interpretation program loading means for loading a printer control command interpretation program transmitted from a host into the program storage memory, and a branching means for appropriately passing control to the printer control command interpretation program. A "printer device" is obtained.

〔Example〕

Next, the present invention will be described in more detail with reference to the drawings showing one embodiment of the present invention.

Referring to FIG. 1, one embodiment of the present invention has a program storage memory 17 in addition to a ROM 15 loaded with a normal basic control program and a printer control command interpretation program.

The basic control program performs basic control and management of the device, such as device initialization and failure diagnosis at power-on and reset.The printer control command interpretation program handles print data received from the host interface 11 and printer control. Interpret the command and save font memory 1
4, a print image is developed on the image memory 13, and an appropriate print command is sent to the I10 processor unit 16 to print. Furthermore, when the printer control command interpretation program receives an extended printer control command interpretation program download instruction and an extended printer control command interpretation program from the host, the printer control command interpretation program is configured to combine the extended printer control command interpretation program already stored in the program storage memory 17. The version numbers of the expansion control command interpretation program received from the host are compared, and only when the version of the program from the host is newer, this program is loaded into the program storage memory. This avoids the inconvenience of a new version replacing an old version.

It also detects a command that is not directed to itself among commands from the host, and transfers control to the extended printer control command interpretation program on the program storage memory 7 to execute the processing of this command.

An example of a printer control command interpretation program that implements the above functions will be explained with reference to the flowchart in FIG. R.O.
The printer control command interpretation program on the M15 receives host data from the host via the host interface 11.

If this host data is print data, it processes the print data by developing the font pattern of the corresponding print data on the image memory 13, and also performs 1-byte processing such as CR (carriage return) and LF (line feed). In the case of a basic control command, the corresponding processes such as printing and line feed execution are performed.

If the host data is neither print data nor a 1-byte basic control command, it is either a 2-byte or more printer control command or a command error.

Determines whether an extended printer control command interpretation program is loaded on the program storage memory 7, and if this program is loaded, transfers control to this program and entrusts it with interpretation and processing of printer control commands. .

If this program does not exist, it interprets it as its own printer control command, that is, on the ROM 15, and processes the corresponding command. If the corresponding command does not exist, it performs error processing as a command error.

The extended printer control command interpretation program in the called program storage memory 17 executes the corresponding command if it exists, and if it does not exist, the extended printer control command interpretation program in the ROM stores 2 bytes or more. With such a configuration, it is possible not only to add new control commands, but also to replace existing printer control commands provided on the ROM.

If the program storage memory 14 is volatile, the extension commands must be downloaded every time the printer device is powered on, which places a heavy burden on the host.
It is preferable to use non-volatile memory as the program storage memory.
In addition to RAM backed up by M or a battery, a combination of an inexpensive volatile RAM and a magnetic recording medium such as a hard disk can also be used. In the latter case, by storing the program on a magnetic recording medium and loading this program onto volatile RAM when the device is powered on,
It can be used as virtually non-volatile memory.

[Effects of the Invention] As described above, according to the present invention, printer control commands can be easily extended and upgraded by providing a program storage memory inside the device and downloading an extended printer control program from the host. This is a printer device that can manage the version number of this extended printer control program inside the device, so there is no risk of a newer version of the program being replaced by an older program.Usually, the host of this printer device is a computer or communication terminal. Since this extended printer control program can be distributed using the FDD device and communication line installed in the host, it is economical because it requires less expensive floppy disks and network line usage fees than ROM cassettes.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2(a)
and (b) is a flowchart showing the operation of this embodiment,
FIG. 3 is a block diagram of a conventional printer device, and FIG. 4 is a block diagram of another conventional printer device. 11...Host interface, 12...CPU
Part, 13... Image memory, 14... Font memory, 15. ROM, 16. l107'O setter,
17...Memory for program storage, 38...RO
M cassette holder 39...ROM cassette. (see) Figure 2 1 ω) Figure 2

Claims (1)

[Scope of Claim] A printer device that executes printing by interpreting print data and printer control commands received from a host, comprising: a readable/writable program storage memory; and a program already stored in the program storage memory. program version number comparison means for comparing the version numbers of the program and a new program transmitted from the host; and a printer control command transmitted from the host only when the version number is updated by a signal from the program version number comparison means. A printer device comprising: printer control command interpretation program loading means for loading an interpretation program into the program storage memory; and branching means for appropriately passing control to the printer control command interpretation program.