Method and apparatus for remotely altering programmable firmware stored in an interactive network board coupled to a network peripheral

Abstract

Method and apparatus for remotely altering programmable firmware stored in a PROM disposed on a target interactive network board having a local area network interface comprises activating a local area network communication program. The communication program operates to broadcast an inquiry through the local area network for the designated interactive network board, to receive location information of the designated board in response to the broadcast inquiry, and to establish communication with the designated board. A ROM firmware image is downloaded into a RAM on the designated board, preferably through the local area network interface. A verifying step verifies that the ROM firmware image stored in RAM is valid, and the PROM is controlled to erase memory locations, to transfer preservable data from the PROM into predetermined locations within the ROM firmware image stored in RAM, and to load into the PROM the ROM firmware image from the RAM. After completing the flash operation, the designated board may be re-initialized to execute instructions from the firmware image stored in the PROM.

Claims

What is claimed is:

1. In a local area network, a method for remotely updating an old ROM firmware image stored in a PROM disposed on a designated interactive network board having a local area network interface, said method comprising the steps of:

activating a local area network communication program, said communication program operating (i) to broadcast an inquiry through the local area network for the designated interactive network board, (ii) to receive location information of the designated interactive network board in response to the broadcast inquiry, and (iii) to establish communication with the designated interactive network board via the local area network interface;

downloading, over the local area network interface, a new ROM firmware image into a RAM on the designated interactive network board;

verifying that the new ROM firmware image stored in the RAM is valid prior to loading the new ROM firmware image from the RAM into the PROM;

updating firmware of the PROM, in a case where the new ROM firmware image is valid, by (i) storing a predesignated portion of the old ROM firmware image in the RAM, (ii) erasing predetermined PROM storage locations, and (iii) loading the new ROM firmware image and the predesignated portion of the old ROM firmware image from the RAM into the PROM; and

re-initializing the designated interactive network board, in a case where the new ROM firmware image is valid, using the new ROM firmware image and the predesignated portion of the old ROM firmware image loaded in the PROM.

2. A method according to claim 1, further comprising the step of, after said step of re-initializing, loading instructions from the PROM to the RAM.

3. A method according to claim 1, wherein the step of activating includes the step of storing the new ROM firmware image in a local area network file server.

4. A method according to claim 3, wherein the step of downloading includes the step of retrieving, from the local area network file server, the new ROM firmware image.

5. A method according to claim 1, further comprising the step of matching a designated identifier stored in the PROM with a designated identifier in the new ROM firmware image stored in the RAM, and in the case the designated identifier stored in the PROM does not match the designated identifier stored in the RAM, further including the step of outputting an error signal from said board.

6. A method according to claim 1, wherein said step of verifying performs a checksum operation on the new ROM firmware image stored in the RAM and, in the case the checksum operation fails, performs a further step of outputting an error signal from said board indicating that the checksum operation has failed.

7. A method according to claim 1, wherein said step of controlling controls the PROM to erase all memory locations except a board identifier location.

8. A method according to claim 7, wherein said step of updating loads the new ROM firmware image from the RAM into erased memory locations of the PROM.

9. A method according to claim 1, wherein the activating step broadcasts a MAC address through the LAN and established communication with the board after the board has responded to the inquiry by sending its address and location.

10. A method according to claim 1, further comprising the step of disposing a test interface on said board for providing a communication link to a test station, and wherein said step of downloading includes the step of downloading the new ROM firmware image, the designated identifier, and a checksum through the test interface from the test station into the RAM.

11. A method according to claim 1, further comprising the step of disposing a remote LAN device for remotely downloading the new ROM firmware image, the designated identifier, and a checksum packet into the RAM via the local area network interface.

12. A method according to claim 1, further comprising the step of disposing a SCSI interface on the board.

13. A method according to claim 1, further comprising a step of verifying a designated identifier in the new ROM firmware image with a designated identifier stored in a ROM disposed on the designated interactive network board before said step of updating.

14. In a local area network, an apparatus for remotely altering an old ROM firmware image stored in a PROM disposed on a designated interactive network board having a local area network interface, said apparatus comprising:

local area network communicating means (i) for broadcasting an inquiry through a local area network for the designated interactive network board, (ii) for receiving location information of the designated interactive network board in response to the broadcast inquiry, (iii) for establishing communication with the designated interactive network board via the local area network interface, and (iv) for downloading to the designated interactive network board, over the local area network interface, a new ROM firmware image, a designated identifier code, and a checksum packet;

a RAM, resident on the designated interactive network board, for storing the new ROM firmware image, designated identifier code, and checksum packet;

a PROM, resident on the designated interactive network board, for storing the old ROM firmware image and another designated identifier code;

comparing means, resident on the designated interactive network board, for performing a checksum operation on the new ROM firmware image stored in said RAM, prior to loading the new ROM firmware image into said PROM, using the checksum packet stored in said RAM; and

control means for controlling said PROM, in a case where the new ROM firmware image is valid, (i) to preserve a predesignated portion of the old ROM firmware image by storing the predesignated portion of the old ROM firmware image in said RAM, (ii) to erase predetermined PROM storage locations, (iii) to load the new ROM firmware image and the predesignated portion of the old ROM firmware image from said RAM into said PROM, and (iv) to re-initialize the designated interactive network board using the new ROM firmware image and the predesignated portion of the old ROM firmware image loaded in said PROM.

15. An apparatus according to claim 14, wherein said comparing means compares the designated identifier code stored in the RAM with the another designated identifier code stored in said ROM.

16. An apparatus according to claim 14, wherein the designated interactive network board is coupled to a LAN printer.

17. An apparatus according to claim 14, wherein the RAM comprises a dynamic RAM.

18. An apparatus according to claim 14, wherein the PROM comprises a flash EPROM.

19. Apparatus according to claim 14, further comprising a test interface, disposed on said designated interactive network board and connected to said RAM, for providing a communication link to a test station, and wherein the new ROM firmware image, designated identifier, and a checksum are downloaded through the test interface from said test station into the RAM.

20. An apparatus according to claim 14, further comprising a remote LAN device, connected to said local area network communicating means via the local area network interface, for remotely downloading the new ROM firmware image, designated identifier, and checksum packet into the RAM.

21. Apparatus according to claim 14, further comprising a SCSI interface disposed on said designated interactive network board for providing a communications link to a peripheral device.

22. In a local area network (LAN), an apparatus for remotely altering old ROM firmware in a PROM disposed on an interactive network board coupled to the LAN, said apparatus comprising:

a LAN interface, disposed on the interactive network board, for receiving from a remote LAN location, new ROM firmware and a verification signal;

a RAM, disposed on the interactive network board, for storing the new ROM firmware, a predesignated portion of the old ROM firmware, and the verification signal; and

a processor, disposed on the interactive network board, for (i) causing the new ROM firmware and verification signal to be stored in said RAM, (ii) verifying that the new ROM firmware is valid using the verification signal prior to loading the new ROM firmware into the PROM, (iii) writing the predesignated portion of the old ROM firmware the PROM to said RAM in a case where the new ROM firmware is valid, (iv) updating the old ROM firmware in the PROM by loading the new ROM firmware and the predesignated portion of the old ROM firmware into the PROM from said RAM in a case where the new ROM firmware is valid, and (v) re-initializing the interactive network board using the new ROM firmware and the predesignated portion of the old ROM firmware stored in the PROM in a case where the new ROM firmware is valid.

23. In a local area network, an apparatus for remotely altering an old ROM firmware image stored in a PROM disposed on a designated interactive network board having a local area network interface coupled to the local area network, the local area network interface for downloading a new ROM firmware image and a checksum packet over the local area network, said apparatus comprising:

a RAM, resident on the designated interactive network board, for storing the new ROM firmware image and the checksum packet;

a PROM, resident on the designated interactive network board, for storing the old ROM firmware image;

comparing means, resident on the designated interactive network board, for performing a checksum operation on the new ROM firmware image stored in said RAM using the checksum packet stored in said RAM in order to validate the new ROM firmware image, the checksum operation being performed prior to loading the new ROM firmware image into said PROM; and

control means, resident on the designated interactive network board, for controlling said PROM to update at least a portion of the old ROM firmware image stored in said PROM in a case where the new ROM firmware image is valid by (i) transferring portions of the old ROM firmware image which are to be preserved to said RAM, (ii) erasing from said PROM at least those portions of the old ROM firmware image which are not to be preserved, (iii) loading from said RAM into said PROM the new ROM firmware image and the portions of the old ROM firmware image transferred to said RAM, and (iv) re-initializing the designated interactive network board using the new ROM firmware image and the portions of the old ROM firmware image transferred to said PROM.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a circuit board which is coupled to a local area network peripheral (e.g. a printer) and which allows the peripheral to be an intelligent, interactive network member eliminating the necessity of dedicating a personal computer to manage the peripheral. More particularly, the present invention relates to a method and apparatus for remotely altering programmable firmware stored in an electronically erasable read-only memory (EPROM) on an interactive network board coupled to a peripheral device.

2. Related Art

Local Area Networks ("LANs") are known for coupling together a plurality of personal computers with peripheral devices such as printers, copiers, etc., to provide for enhanced communication and shared resources. Heretofore, peripherals such as printers coupled to a LAN were rather unintelligent, merely accepting information from the LAN and printing such information on a hard copy. Moreover, such printers usually required a host personal computer ("PC") to effectively manage the flow of data to the printer, i.e., to act as a "server" for the printer. This almost always required that the host PC be dedicated solely to the printer server task.

A number of products have recently appeared which ostensibly eliminate the need for such a dedicated PC by incorporating hardware and software into a circuit board which may be coupled into the peripheral in order to perform limited server functions. For example, ASP Computer Products, Inc. provides a device known as "JetLAN/P" which acts as a stand-alone print server for Novell networks. The JetLAN/P.RTM. device couples to a LAN using a 10Base-2 thin coaxial cable or a 10Base-T twisted-pair cable. However, the JetLAN/P.RTM. couples to the printer only through the printer's parallel port. Thus, while print information can be sent to the printer, the amount of printer status information which can be returned from the printer is severely restricted. For example, such a device may obtain "off-line" and "out of paper" status from the printer, but little else. Such a device does very little toward making the printer a truly intelligent, responsive member of the network.

Other known devices for coupling a printer to a LAN include the Hewlett-Packard Jet Direct.RTM. C2071A/B and C2059A, the Extended Systems EtherFlex.RTM., the Intel NetPort.RTM. and NetPort II.RTM., the Castelle LANPress.RTM. and JetPress.RTM., and the MiLAN FastPort.RTM.. However, all of these devices suffer from the same disadvantages as the ASP JetLAN in that they do not allow the printer to transmit sufficient amounts of data to the LAN to enable the printer to be an effective and intelligent member of the network.

Conventionally, a manufacturer formats and stores executable programs into programmable memories within computers and peripheral devices therefor. These executable programs generally are unalterable by the customer. Therefore, in the case the device requires an updated version of an executable program or if it is determined that the executable file does not operate properly and the device requires servicing for the program, the executable program within the computer or the peripheral device must be altered either at the site of manufacture or at the site of the customer by a manufacturer's representative in order to have this function performed. For example, conventional printers store executable programs in ROM. These executable programs, which affect the manner in which an image is to be formed, are unalterable by the customer. Thus, if it is determined, after the product has been shipped to the customer, that there is a problem in the executable software, the manufacturer either has to recall the printer or must send a service representative out to the location of the printer at which point either an update of the software program or a new pre-programmed chip is installed.

Heretofore, it has not been possible to remotely alter the executable files within a network peripheral device through a local area network from a remote LAN device. That is, a computer or a peripheral device could not be accessed through the LAN in order to alter or add additional executable files, and in addition, to receive remote commands through the LAN to execute the altered executable files or newly added files. Consequently, software updates and added executable files must be performed by the manufacturer or at the customer's site by a service representative which is not only untimely, but expensive.

SUMMARY OF THE INVENTION

The present invention overcomes the drawbacks noted above by providing structure and function on a circuit board coupled to a peripheral which will permit the peripheral to be a responsive, intelligent member of a network.

In one aspect of the present invention, a method for remotely altering programmable firmware stored in an interactive network board is provided whereby firmware can be remotely altered by either revising or adding additional executable files stored in a PROM by downloading either an entire ROM firmware image or a portion of a ROM firmware image from a remote LAN device to the PROM on the interactive board. According to this aspect of the invention, a method for remotely altering programmable firmware stored in a designated interactive network board having a local area network interface comprises the step of activating a local area network communication program. The communication program operates to broadcast an inquiry through the local area network for the designated interactive network board, to receive location information of the designated board in response to the broadcast inquiry, and to establish communication with the designated interactive network board. A ROM firmware image is downloaded into a RAM on the designated interactive board through the local area network interface. A verifying step verifies that the ROM firmware image stored in RAM is valid. The PROM is controlled to transfer preservable data from PROM into predetermined locations within the ROM firmware image stored in RAM, to electronically erase all erasable locations in the PROM, and to flash into the PROM the ROM firmware image from the RAM. After completing the flash operation, the interactive network board is re-initialized and receives instructions from the firmware image stored in PROM.

In a related aspect, the invention provides an apparatus for remotely altering programmable firmware stored in a designated interactive network board having a LAN interface which comprises local area network communicating means for broadcasting an inquiry through the local area network for the designated interactive network board, for receiving location information of the designated board in response to the broadcast inquiry, and for establishing communication with the designated board. A RAM, resident on the designated board, stores process steps. A PROM stores a ROM firmware image which contains process steps, and stores a designated identifier code. Comparing means compares a checksum of the ROM firmware stored in RAM with a checksum packet received from the LAN. Control means controls the PROM to preserve predesignated data by storing that data within the ROM firmware image in RAM, to electronically erase storage locations of the PROM in accordance with the process steps stored in RAM, and to control the loading of the ROM firmware image from RAM into the PROM.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-noted advantages and features of the present invention will become more readily apparent from the following detailed description of the preferred embodiments when taken in conjunction with the Drawings in which:

FIG. 1 is a block diagram of a Local Area Network according to the present invention;

FIG. 2 is a block diagram of a plurality of Local Area Networks coupled together;

FIG. 3 is a block diagram showing the Network Expansion Board according to the present invention coupled between the Local Area Network and the printer;

FIG. 4 is a block diagram of the Network Expansion Board according to the present invention;

FIGS. 5A, 5B and 5C comprise a top-level flowchart showing the basic functions of the Network Expansion Board according to the present invention;

FIG. 6 is a diagram showing the sequence in which software modules are loaded from the Network Expansion Board ROM to RAM;

FIG. 7 is a block diagram showing hardware and software interfaces between the LAN and the Network Expansion Board;

FIG. 8 is a flowchart showing how the EPROM firmware is configured for placing the Network Expansion Board in an operational mode;

FIG. 9 is a chart showing the physical construction of different frame packets used on Ethernet;

FIG. 10 is a flowchart showing the operation of a PRESCAN software module;

FIG. 11 is a chart showing that the PRESCAN module may be used with other software protocols;

FIG. 12 is a chart for explaining the software structure of the SAPSERVER program;

FIG. 13 is a flowchart showing the operation of SAPSERVER;

FIG. 14 is a flowchart showing the operation of a CPINIT program;

FIG. 15 is a flowchart showing the operation of a CPCONSOL program;

FIGS. 16A and 16B comprise a flowchart showing the operation of CPSOCKET program;

FIGS. 17A and 17B comprise a flowchart showing the automatic logging of peripheral statistics;

FIG. 18 is a flowchart showing how multi-tasking processing is performed;

FIG. 19 is a flowchart showing how to place the printer in a safe, default configuration;

FIG. 20 is a flowchart showing the downloading of executable files to the Network Expansion Board from the local area network;

FIG. 21 is a flowchart showing the loading of independently-executable modules in the EPROM of the Network Expansion Board;

FIG. 22 is a block diagram showing Network Expansion Board EPROM flash protection circuitry;

FIG. 23 is a flowchart showing the operation of the circuitry of FIG. 22;

FIG. 24 is a flowchart showing the operation of remotely loading firmware in the Network Expansion Board EPROM;

FIG. 25 is a block diagram showing a hardware configuration for testing the Network Expansion Board; and

FIGS. 26A and 26B comprise a flowchart showing a method of testing the Network Expansion Board using the test configuration of FIG. 25.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In its general aspects, the present invention provides hardware and software solutions for making a network peripheral, such as a printer, an interactive network member capable not only of receiving and processing data received from the network, but of transmitting to the network significant amounts of data such as detailed status information, operational parameters, and even data input to the peripheral through other modalities such as scanning, facsimile reception, etc. By integrating such hardware and software with the peripheral, it is possible to eliminate the requirement for dedicating a personal computer to the peripheral to act as a peripheral server.

1. ARCHITECTURE

FIG. 1 is a block diagram showing the present invention incorporated into a Network Expansion Board ("NEB") 2 coupled to a printer 4 which has an open architecture (to be discussed below). The NEB 2 is coupled to the LAN bus 6 through a LAN interface 8, for example, Ethernet interfaces 10Base-2, 10Base-T, or 10Base-5, respectively, with a Coax connector, an RJ45 connector, or a DB15 connector (AUI). Also coupled to the LAN 6 may be such network members as PC 10, PC 12, PC 14 (which in this case acts as the network administrator if the administrator has logged in at that PC; to be discussed below), and a printer 16 (with embedded QSERVER functionality; also to be discussed below). Other LAN members may include PC 18 (acting as a print server; to be discussed below) with attached printer 20, PC 22 (acting as an RPRINTER; to be discussed below) with attached printer 24, and printer 26 which is coupled to the LAN 6 through a NetPort device 28 (discussed in the Background of the Invention above). A file server 30 is coupled to the LAN 6 and serves as a "library" for files to be transmitted and processed on the LAN. The file server 30 may have attached printers 32 and 34.

In more detail, the network depicted in FIG. 1 may utilize any network software such as Novell or Unix software in order to effect communication among the various network members. The present embodiments will be described with respect to a LAN utilizing Novell NetWare.RTM. software (to be discussed in greater detail in section 3a below) although any network software may be used. A detailed description of this software package may be found in the publications "NetWare.RTM. User's Guide" and the "NetWare.RTM. Supervisor's Guide" by M&T Books, copyrighted 1990, incorporated herein by reference. See also the "NetWare.RTM. Print Server" by Novell, March 1991 edition, Novell Part No. 100-000892-001. Briefly, the file server 30 acts as a file manager, receiving, storing, queuing, caching, and transmitting files of data between LAN members. For example, data files created respectively at the PCs 10 and 12 may be routed to the file server 30 which may order those data files and then transfer the ordered data files to a printer 24 upon command from a print server in PC 18. The file server 30 may include or may be coupled to a large capacity storage member such as a 10 Gigabyte hard disk subsystem. Furthermore, the printers 32 and 34 may be coupled to the file server 30 to provide additional printing stations, if desired.

While personal computer equipment is illustrated in FIG. 1, other computer equipment may also be included, as appropriate to the network software being executed. For example, Unix workstations may be included in the network when Unix software is used, and those workstations may be used in conjunction with the illustrated PC's under appropriate circumstances.

PCs 10 and 12 may each comprise a standard work station PC capable of generating data files, transmitting them onto the LAN, receiving files from the LAN, and displaying and/or processing such files at the work station. The PCs 10 and 12, however, are not capable of exercising control over LAN peripherals (unless the network administrator is logged into that PC).

A PC capable of exerting limited control over LAN peripherals is PC 22 which includes an embedded RPRINTER program. The RPRINTER program is a MS-DOS Terminate and Stay Resident ("TSR") program which runs on a work station to allow users to share the printer 24 connected to the work station. RPRINTER is a relatively unintelligent program that does not have the ability to search printer queues for work. RPRINTER gets its work from a PSERVER (to be discussed below) that is running elsewhere in the network. Because they communicate with the attached printer over the printer's parallel port, RPRINTERs are able to obtain only limited status and to return that status information to the responsible PSERVER over the LAN 6. From a control standpoint, an RPRINTER allows stopping of a print job and little more. Some printers include RPRINTER features by offering internal or external circuit boards that provide the same limited features of the RPRINTER TSR program running in a personal computer.

Another network entity capable of exercising limited control over LAN peripherals is a printer 16 with attached circuit board 36 having an embedded QSERVER program. Here, the QSERVER program runs inside an HP LaserJet III.RTM. SI printer, and has the capability of searching the file server 30 print queues for eligible print files. The QSERVER's search queues cannot be dynamically altered nor does the QSERVER respond to any form of status inquiry. The benefit of the QSERVER is its ability to autonomously search for work. The QSERVER does not require a PSERVER running elsewhere in the system to feed it work. Since the QSERVER does not have a corresponding PSERVER and it does not itself have any status and control capabilities, it offers less control than even the RPRINTER. A QSERVER also differs from a PSERVER in that it has extremely limited notification features and cannot print banners at the beginning of each print job.

Another network member having a QSERVER capability is printer 26 which is coupled to the LAN 6 through an external NetPort device 28.

Other peripheral server programs may be executed to service various peripherals, such as scanners, copiers, facsimiles etc., and servers may also be provided based on network software protocol such as a Unix-compatible Line Printer Remote server ("LPR").

A LAN member capable of exercising significant control over LAN peripherals is the PC 18 having a PSERVER program embedded therein. PSERVER has the ability to service multiple user-defined print queues, perform dynamic search queue modification, and provide defined notification procedures for exception (failure) conditions and status and control capabilities. PSERVER is provided in several forms. PSERVER.EXE is a program that runs dedicated on a work station and controls both local and remote printers. The local printers can be connected to either serial or parallel ports, and the remote printers are printers running elsewhere in the system. Two other forms of the PSERVER program are the PSERVER.VAP and the PSERVER.NLM. These are PSERVER versions that run on the file server 30 itself. The .VAP version is for NetWare.RTM. 286, and the .NLM version is for NetWare.RTM. 386. While the PSERVER provides much more capability than the RPRINTER and QSERVER, one of its drawbacks is that the .EXE version requires a dedicated personal computer.

A dedicated personal computer running PSERVER.EXE can control as many as 16 local/remote printers and can request print information from many file server queues. However, there are several drawbacks to relying on PSERVER to control network printing services. The first drawback is that multiple printer streams must all be funnelled through a single network node and personal computer processor. This can become a bottleneck. The second drawback is that for the most efficient operation, the printers should be connected to the computer locally, as with the printer 20. This can be an inconvenience for users since it requires the printers to be clustered around PC 18. The third drawback is that if the controlled printers are remote as in the case of printer 24 which is serviced by RPRINTER, then the print data must make the trip from the file server 30 to the PSERVER PC 18 and then be retransmitted to the printer running RPRINTER. This is inefficient.

The fourth drawback is the limited amount of printer status and control information offered through PSERVER. It has already been stated that APRINTER does not allow for much more than rudimentary status such as "out of paper" and "off line". PSERVER itself for locally and remotely connected printers does not offer much more than this because it was designed with consideration of the limitations of the personal computer parallel port. The PSERVER program also allows for its own status and control.

The Network Expansion Board 2 installed in the printer 4 provides many advantages and enhanced flexibility over the network peripheral control entities discussed above. In particular, the NEB-embedded controller offers RPRINTER, PSERVER and LPR (Line Printer Remote) functionality (through CRPRINTER, CPSERVER and CLPR programs to be discussed in section 3d below). There is an initialization program named CPINIT (to be discussed in section 4h below) which allows the network administrator's PC 14 complete control over the configuration of NEB features. Due to its embedded nature and the open architecture of printer 4, the NEB will have the ability to offer a wide variety of status and control features to the network. That is, verbose amounts of status information may be provided from the printer 4 to the LAN 6, and a great deal of control information may be provided from the LAN 6 to the printer 4 (for example, exercising printer front panel functions from the PC 14).

To access the extended amount of information available in the NEB, a program called CPCONSOL is resident in the network administrator's PC 14 and allows the system administrator to view all of the printer information which is exported from the printer 4 by the NEB 2. The printer information is available even if the RPRINTER functional configuration (CRPRINTER) of the NEB 2 is selected. The PSERVER functional configuration (CPSERVER) of the NEB 2 will control the printer 4 that contains the board. This option will have all of the standard PSERVER queue search capabilities as well as the notify and status features. All of these features can be dynamically controlled from a remote work station. The NEB environment and its ability to export extended status and control information from the printer 4 makes the combination of the NEB 2 and the printer 4 much more powerful than the standard RPRINTER, QSERVER, or PSERVER print methodologies currently available.

The CPCONSOL program (to be discussed in greater detail in section 4i below) provided in the network administrator's PC 14 is capable of interfacing with the NEB 2 (and other network members) to perform such functions as displaying current information for a selected network device (interface information, control information, font information, layout information, quality and common environment information, duplex information, and miscellaneous information). CPCONSOL is also capable of setting or modifying the safe (default) condition of a network device. CPCONSOL may also activate or deactivate applications of the NEB 2 such as CPSERVER or CRPRINTER (to be discussed below, but generally similar to the PSERVER and RPRINTER software packages discussed above). Furthermore, the CPCONSOL enables the PC 14 to display a log file, clear the log file, or write the log file to memory such as a local or a file system disk. CPCONSOL can also display such printer-related information on PC 14 as the number of jobs, the number of pages per job, the number of pages per minute, the time per job, the number of total pages per day, the number of total jobs per day, and the number of days. The CPCONSOL program is also capable of displaying on the PC 14 such network-related information as media related and non-media related information, and of clearing such network statistics.

The CPINIT program (to be discussed in greater detail in section 4h below) resident in the network administrator's PC 14 can set up application information print services such as CPSERVER and CRPRINTER and configure those applications. CPINIT is also capable of setting and/or displaying device information such as time/date/time zone, buffer size, disk size, logging flag, log limit, and a safe (default) environment flag. CPINIT can also restore default service headings, reset the NEB 2, reboot the NEB 2, command a font download, command an emulation download, display a NEB power-on-self-test ("POST") error, display the NEB 2 firmware level, display the current log file size, etc.

By providing the NEB 2 with PSERVER and RPRINTER capabilities, the present invention achieves, with a single circuit board, enhanced functionality for the printer 4 with respect to the LAN 6. Therefore, the printer 4 is a true "networked" printer and not just a printer connected to a network.

While the present invention offers unique advantages on the LAN 6, these advantages are also realized when the LAN 6 is coupled to one or more other LANs in a Wide Area Network ("WAN"). FIG. 2 depicts such a WAN which includes a first LAN 41 including a server S1 40, PC's 42, 44, and 46, and a printer 48. The server S1 40 is coupled to a backbone 50 over a bus 52. The backbone 50 is nothing more than an electrical connection between a plurality of buses. Also connected to the WAN is a second LAN 61 comprising server S2 60, PC's 62, 64, and 66, and a printer 68. Server S2 60 is coupled to backbone 50 over bus 54.

The WAN may also include a remote LAN 71 comprising server S3 70, PC's 72, 74 and 76 and a printer 78. Since the LAN 71 is remote from the remainder of the system, it is coupled to backbone 50 through a bus 56, a transponder (which may include a modem) 58, and a communication line 59.

In such a WAN, assume that PC 42 is a PSERVER requesting the use of printer 78. If the printer 78 is equipped with a NEB according to the present invention, a direct communication link can be established between the PC 42 and the printer 78 whereby job information can be sent to printer 78, and status and control information can be sent from printer 78 to the LAN 41. Therefore, the NEB according to the present invention achieves its enhanced functionality even when installed in a peripheral coupled to a WAN.

FIG. 3 is a block diagram depicting the connection of the NEB 2, according to the present invention, with the printer 4 and the LAN 6. The NEB 2 is directly connected to the LAN 6 via LAN interface 101, and also to the printer 4 via a bi-directional interface, here a Small Computer System Interface ("SCSI") 100. The SCSI interface 100 is coupled to an SCSI bus 102 of the printer 4.

The NEB can also service additional SCSI devices, such as other printers (RPRINTERs) or other peripherals, daisy-chained on the SCSI bus using standard SCSI connectivity protocol. Also, the NEB may be used to drive other peripherals across the ELAN itself.

The printer 4 is preferably an open-architecture printer including the SCSI bus 102 and SCSI interfaces 104 and 106o Printer 4 also includes a processor 108 such as a REDUCED INSTRUCTION SET COMPUTER ("RISC") which communicates with a RAM Memory 110 and with a printing engine 112 which actually drives the printing mechanism. The RISC processor also communicates with NVRAM 111 for storing information which needs to be maintained between power cycles, such as user-defined information, and with ROM 113 from which RISC processor 108 executes printer control. The printer 4 may also include a hard disk 114 capable of holding large amounts of data in a non-volatile way. Printer 4 also has a front panel display 116, and a keyboard 115 for inputting control commands to the printer.

Preferably, the printer 4 includes an open architecture which takes advantage of the bi-directional nature of the SCSI interface 100 to provide a great deal of status (and other) information from the printer 4 to the LAN 6 via the NEB, and also to allow fine control of the printer from a remote location. For example, such open architecture when used with the bi-directional SCSI interface permits most or all of the information on the front panel display 116 of printer 4 to be exported to a remote location, and also permits most or all of the control functions of the printer front panel keyboard 115 to be activated from the remote location.

Briefly, the open-architecture printer 4 comprises four major subsystems: Communication; Job Pipe; Page Layout and Raster functions; and Systems Services. The Communication subsystem handles the different communication devices and initiates the start of a job application. When the printer starts to receive data, the Communication subsystem sends the first part of the incoming data to each emulator for examination. The first emulator that can process the data becomes the Job Pipe driver. The system then constructs a Job Pipe to process the data (data flows into one end of the pipe, and page images flow out of the other end). This Job Pipe comprises many segments one of which is the Job Pipe driver.

The Job Pipe subsystem has a Pipe driver segment (the application for an emulator) and input and output segments. The input and output pipe segments have at least two other segments: for input, source and source filter segments; and for output, an output filter and a data sink. The input segment of the Communication subsystem delivers the input data which can be supplemented by information from a file system. The Pipe driver processes input and supplemental data. It also generates imaging commands and page layout information that it sends to the output segment. The Pipe driver may store this information to the printer disk (if present). The output segment sends this data to the Page Layout and Raster subsystem.

The Page Layout and Raster subsystem takes the imaging and page layout information and converts it to a raster image for the print engine 112. This section operates completely separately from Job Pipe.

The System Services subsystem provides file system access, console access, font services, basic system services, and image generation services. Therefore, a printer 4 having such an open architecture will take full advantage of the intelligent, interactive NEB 2 to provide increased functionality to the printer 4 and the entire network.

2. HARDWARE

FIG. 4 is a block diagram of the NEB 2 showing the major components thereof. The NEB 2 is coupled to the LAN 6 through network connectors 202, 203, and 204. Preferably, the connector 202 is an RJ45 capable of accepting a 10Base-T connection. The connector 203 may comprise a DB15 connector for accepting a 10Base-5 connection, while the connector 204 may be a simple Coax connector capable of accepting a 10Base-2 connection. All of the connectors 202, 203, and 204 are coupled to a network controller 206 (preferably an Ethernet Network Controller). However, the connector 204 is first coupled through a transceiver 208.

Power is supplied to NEB 2 from a +5 V power source in printer 4 through the printer expansion port 226. The +5 V power is also provided to the power converters 210 and 212. The power converter 210 provides -9 V power to transceiver 208, while the power converter 212 provides +12 V power for "flashing" (loading; to be discussed in section 4q below) the EPROM 222. Also, the network controller 206 is coupled to an 8 KB static RAM 214.

The heart of the NEB 2 is a microprocessor 216, preferably an NEC V53. The microprocessor 216 is coupled to a serial port 218, currently used for testing. Also coupled to the microprocessor 216 are a 512 KB dynamic RAM 220, a 256 KB flash EPROM 222, an SCSI controller 224 (corresponding to SCSI interface 100 of FIG. 3) a printer expansion port 226, a diagnostics/failure LED 240, a 256 Byte non-volatile RAM 228, a control register 230, and a PROM 232 which stores the Media Access Control ("MAC") address which is the unique name for every EtherNet board.

The architecture of the NEB 2 provides an advantage in that it has unique support features for administration and management of large, multi-area networks. These support features include, for example, printer control and status monitoring from a remote location on the network, (i.e., from the network administrator's office), automatic management of printer configuration after each print job to provide a guaranteed initial environment for the next user, and logs of printer usage statistics accessible across the network for characterizing printer workload and scheduling toner cartridge replacement. A key parameter in the NEB design is the ability to access the printer control state from the NEB 2 through a bi-directional interface, here the SCSI interface 100. This allows the printer console information to be exported to the NEB or to an external network node for the programming of many useful printing support functions.

Table 1 below provides a description of the functions, implementation, and operational notes with respect to the major hardware elements of NEB 2.

                  TABLE 1
    ______________________________________
    Function    Implementation
                              Notes
    ______________________________________
    Network Controller
                National DP 83902
                              With DP8392 Coax
    (206)                     Transceiver
    Ethernet Interfaces:
                10Base-2 (202)
                              Coax connector
                10Base-T (204)
                              RJ45 connector
                10Base-5 (203)
                              DB15 connector
                              (AUI)
    Embedded Proces-
                NEC V53       16-bit/16Mhz MPU
    sor:                      with DMA, timers,
    (216)                     Interrupts
    EPROM (Flash)
                256K Bytes    Network program
    (222)                     code, board BIOS
                              (Basic Input
                              Output Subsystem),
                              diagnostics
    NVRAM       256 Bytes     Printer
    (220)                     Installation
                              Configuration on
                              Network
    DRAM        512K Bytes    Code execution and
    (220)                     data buffering for
                              exp.port
    SRAM        8K Bytes      Buffering of
    (214)                     incoming Ethernet
                              packets
    SCSI Controller
                NCR 53C90A    30-pin, internal
    (224)                     I/F configuration
                              with power
    MAC Address and
                32 Bytes      Stores MAC address
    Hardware ID               and Hardward ID
    PROM (232)                information
    Board Size  100 mm .times. 125 mm
                              Type 2 EXP-I/F
                              PCB, double-sided
                              SMT
    Power       5vdc, 710 ma  DC converter on
                              board for Ethernet
                              +12vdc/-9vdc
    ______________________________________

                  TABLE 2
    ______________________________________
    Function    Implementation Notes
    ______________________________________
    NEB-specific
                CPSERVER (92KB)
                               Customized Print
    functions in NEB           Server
    EPROM       CRPRINTER (40KB)
                               Customized Remote
                               Printer
    NEB-to-Network
                CPSOCKET (30KB)
                               Concurrent multi-
    communication in           protocol operation
    NEB EPROM
    NEB Environment
                (15KB)         Monitor, loader,
    in NEB EPROM               POST, etc.
    Extensions to
                CPCONSOL.EXE   Remote Control &
    NetWare .RTM.
                (180KB)        Stats, Auto-
    PCONSOLE for
                CPINIT.EXE     Reconfiguration,
    Printer     (120KB)        Print Job
    Control/Configur-          Logs/Statistics
    ation in
    Administrator's
    PC 14
    ______________________________________