Electronic typewriter with spell verify

Abstract: A spell verification method and apparatus which comprises inputting characters and operational modes by keystrokes, printing input characters, providing a read only memory having plural dictionaries with spelling information, each dictionary including different but complementary dictionary entries, and executing program steps by a single chip microprocessor which includes an internal memory for storing program steps to control functions of the printer and to control a spell verification function of the electronic typewriter. The single chip microprocessor further includes a detector for detecting whether the read only memory is connected to an interface of the single chip microprocessor. Upon determining the status of the connection, the single chip microprocessor either enables or disables the spell verification function.

Description: The present invention relates to a spell verification electronic typewriter which utilizes a spelling dictionary to verify whether a word is spelled correctly. Conventional electronic typewriters with spell verification include a first microprocessor to control typewriter functions such as keyboard input and printer output, and a second microprocessor to control the spell verification function. Thus, as shown in U.S. Patent No. 4,689,768, a printer processor accepts keyboard input and causes a printing element to print characters that correspond to the input. In response to a request to verify spelling, a spelling verification processor, which is independent of the printer processor and includes its own program and data storage memory, is actuated to determine if the keyed-in word is correctly spelled. It has been considered to combine typewriter functions and spell verification functions into one processor. However, because of the nature and complexity of those functions, it has heretofore been necessary to provide the processor with computer-like structure such as external memories and address and data buses. For example, to control the keyboard and the printer and at the same time provide for access to a spelling dictionary, the processor must ordinarily include an address bus and a data bus to send and receive information to and from the printer and the keyboard, to send and receive information from the spelling dictionary, and to send and receive processor instructions and print data from external program memory and data memory. Moreover, simply to coordinate this computer-like structure and ensure its functionality, the processor must execute extra functions, instructions that are unrelated to electronic typewriter or spell verification functions, such as bus contention functions, device-busy checking, read/write coordination, etc. Such computer-like structure increases the cost and complexity of the electronic typewriter, as well as requiring high development costs. These costs recur for each different model of electronic typewriter. GB-A-2227588 discloses a document processing apparatus which includes a first judgement unit for verifying the spelling of a word while referring to the first correct spelling information stored in a first spelling dictionary. A second judgement unit is provided for verifying the spelling of a word different from those stored in the first spelling dictionary while referring to the second correct spelling information stored in a second spelling dictionary. A connection unit is provided for detachably connecting the second judgement unit to the apparatus main body and a switch is provided for switching the spelling verification judgement process between the first and second judgement units in accordance with the connection state of the second judgement unit relative to the connection unit. An article in Computer Design, Volume 1, No. 2, February 1992, Tulsa, OK, US, pages 122-123 discloses a single chip processing unit provided with a central processing unit, on-chip RAM, on-chip ROM and on-chip I/O ports. EP-A-0458629 discloses a printing apparatus in accordance with the preamble of the claims having input means for manually inputting print information, output means for outputting print information, storage means for storing a spelling information dictionary, and processing means for controlling the output means to output print information based on print information input by the input means and for accessing the storage means in accordance with the print information input by the input means. In accordance with a first aspect the present invention provides a printing apparatus comprising: input means for manually inputting print information; output means for outputting print information; storage means for storing at least one spelling information dictionary; and processing means for controlling said output means to output print information based on print information input by said input means and for accessing said storage means in accordance with print information input by said input means; characterised by address latching means for latching address information from said processing means to said storage means; in that said processing means comprises a single chip microprocessor which has a first dedicated interface comprising a first multi-bit connection to said output means for interfacing to said output means, a second dedicated interface comprising a second multi-bit connection to said storage means, and a third dedicated interface comprising a third multi-bit connection to said address latching means for latching address information from said third dedicated interface to said storage means simultaneously with the delivery of address information from said second dedicated interface to said storage means, said third dedicated interface being further connected to said storage means for receiving spelling information accessed from said storage means; in that said processing means has internal program storage means for storing program instructions for controlling said output means to output the print information; in that said processing means is operative to write a first part of address information through said second dedicated interface to said storage means and a second part of address information through said third dedicated interface to said storage means; and in that said storage means is operative to output the spelling information to said third dedicated interface based on the first and second parts of address information. In accordance with a second aspect the present invention provides a printing method comprising the steps of: storing at least one spelling information dictionary in a storage means; inputting print information; and executing process steps so as to output print information input in said inputting step and so as to access stored spelling information from the stored spelling information dictionary in accordance with input print information; characterised in that the process steps are executed on a single chip microprocessor to control output of print information by sending commands using a first dedicated interface comprising a first multi-bit connection to an output means, to access spelling information using a second dedicated interface comprising a second multi-bit connection for delivering address information to said storage means, and to latch address information output to said storage means from a third dedicated interface comprising a third multi-bit connection using an address latch connected thereto simultaneously with the delivery of address information from the second dedicated interface to said storage means, the third dedicated interface also being connected to said storage means for receiving spelling information accessed from said storage means; in order to access spelling information in said storage means, the microprocessor writes a first part of address information through the second dedicated interface to said storage means and a second part of address information through the third dedicated interface to said storage means; and spelling information is output from said storage means to the third dedicated interface based on the first and second parts of address information. The input means may include a keyboard for manually inputting characters, and the output means may include a printer having a daisy wheel motor, a hammer, a carriage motor, and a ribbon motor. The single chip microprocessor preferably includes an interface port to the keyboard, another interface port to the printer, and other interface ports for accessing the dictionary. The processor for the electronic typewriter may be configured so as to enable it to be used both with and without the spelling dictionary and to be operable without error in either configuration without the need for reprogramming. In this manner, an electronic typewriter with such a processor can be used without modification for both a low-end typewriter without spell verify and a higher-end typewriter featuring spell verify. Advantageously, such an arrangement reduces development costs since the same processor is used regardless of whether a spelling dictionary is included with the typewriter. In this embodiment of the invention, a spell verification processor comprises a microprocessor having a dedicated interface connectable to a dictionary containing spelling information. The microprocessor has a selectably actuatable spell verification mode in which a character string is checked against the spelling information within the dictionary. The microprocessor includes means for checking whether the dictionary is connected to the interface of the microprocessor and wherein the microprocessor is adapted to actuate the spell verification mode in the case the dictionary is connected and to disable the spell verification mode in the case the dictionary is not connected. It is also possible to provide an electronic typewriter with more than one dictionary, for example, an American-english dictionary and a British-english dictionary, one of which is switchably actuated. Such a configuration allows a single electronic typewriter to serve different markets. For example, a British operator can use the same electronic typewriter as an American operator merely by selecting the appropriate dictionary. In this manner, the word "colour", which is correctly spelled in Great Britain but incorrectly spelled in the U.S., will only be flagged as misspelled if the American-english dictionary is selected. In this embodiment of the invention, a printing apparatus comprises storage means including a single read only memory having plural dictionaries of spelling information, designation means for designating one of the plural dictionaries, and process means for selecting the dictionary in accordance with the designation by the designation means. Embodiments of the present invention will now be described with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of an electronic typewriter according to an embodiment of the invention; Fig. 2 is a plan view of the keyboard of the electronic typewriter shown in Fig. 1; Fig. 3 is a schematic drawing of the electronic typewriter shown in Fig. 1; Fig. 4 is a memory map of the RAM within the microprocessor shown in Fig. 3; Fig. 5 is a flow chart of power-up processing performed by the electronic typewriter shown in Fig. 1; and Fig. 6 is a flow chart of the spell verification function. A perspective view of the electronic typewriter 1 of an embodiment of the present invention is shown in Fig. 1 and includes input means such as keyboard 2 and output means such as printer 30. A detailed diagram of the keyboard 2 of an embodiment of the present invention is shown at Fig. 2. The keyboard 2 includes a alphanumeric keyboard section 3, and a guide template section 7. The keyboard section 3 is a typical alphanumeric keyboard in which a plurality of alphanumeric keys 4 are used to input print information such as alphanumeric characters. The alphanumeric keyboard section includes control keys which include CODE key 6 and MODE key 8. The control keys are used to actuate certain modes or functions performed by the typewriter such as those modes or functions which are indicated on the guide template section 7. For example, when pressing the key sequence of "CODE" followed by "6" (hereafter "CODE + 6"), the center function is actuated as indicated on the guide template at 10. In another example, by pressing key sequence MODE + 7, character pitch on the typewriter is set to 10 cpi and by pressing MODE + 8 the pitch is set to 12 cpi. In addition to the foregoing features of the typewriter, there are two typewriter functions which are available when the typewriter is installed with stored dictionaries. These features include a spell verification function which is actuated by pressing the key sequence "CODE" followed by 9 (hereinafter "CODE + 9") and indicated on the guide template at 14. A dictionary selection function, which is indicated on the guide template at 16, is used to select between an American-english dictionary and a British-english dictionary by pressing "CODE" followed by "0" (hereinafter "CODE + 0"). The current selection is indicated by an audible tone. If the spell verification function is actuated and currently using the British-english dictionary, pressing CODE + 0 will cause the dictionary selection function to change dictionaries from the current British-english dictionary to the American-english dictionary instead. Pressing the key sequence CODE + 0 again will cause the dictionary selection function to change back to the British-english dictionary. Fig. 3 is a schematic diagram of the components of the electronic typewriter 1. The electronic typewriter includes microprocessor 32 having plural interface ports for accessing external peripheral devices such as keyboard 2, printer 30 and dictionary ROM 42. The microprocessor includes an internal read only memory (ROM) 40 which stores control information such as process steps for controlling typewriter functions such as keyboard and printer operations as well as for controlling spell verify functions. The microprocessor 32 also includes an internal random access memory (RAM) 38 for providing a temporary word buffer which contains input print information, such as character strings input by keyboard 2, and three flag indicators which indicate respectively if the external dictionary ROM is present, whether the spell verification function is enabled or disabled, and the current dictionary selection. Jumpers 19 are provided so as to permit microprocessor 32 to operate with keyboards whose configurations are different from that shown in Figure 2. Specifically, the physical configuration of the keyboard may differ depending on the country in which the electronic typewriter is intended to be delivered. For example, a keyboard for Germany may have the "y" and "z" keys interchanged. In order to facilitate the manufacturing of the various keyboards without changing the programming in microprocessor 32, microprocessor 32 inspects the jumper configuration and operates accordingly. Printer 30 may be a conventional printer comprised by daisy wheel motor 20, hammer 22, carriage motor 24, and ribbon motor 26. Microprocessor 32 controls the movement of daisy wheel motor 24, hammer 22, and carriage motor 24 in accordance with input print information and in accordance with the program stored in ROM 40. Other output means may be used, for example, ink jet printers, bubble jet printers, and thermal transfer printers. In the illustrated embodiment, a single chip microprocessor is preferably used, such as a Mitsubishi M38002M4, which features 384 bytes of internal random access memory (RAM), 16 kilobytes of internal ROM and eight interface I/O ports for sending/receiving control information to the keyboard and the printer, and for sending/receiving address information and data to/from the external dictionary ROM. The microprocessor 32 contains sufficient internal storage in RAM 38 and ROM 40 to store input character strings and words, control software for controlling the electronic typewriter, and process steps for the spell verification functions. Dictionary ROM 42 is a single ROM chip in which is stored two complete dictionary databases of spelling information, one for American-english words and the other for British-english words. Both dictionary databases are approximately the same size, same format, and contain different but complementary entries. For example, an entry for the word "color" in the American-english dictionary will have a different but complementary word "colour" stored in the British-english dictionary. Likewise, whereas the American-english dictionary may have an entry for the word "gasoline", the British-english dictionary may have an entry for the word "petrol". Not all words are necessarily included in each dictionary; for example, an entry for the word "varsity" appears in the American-english dictionary but there is no corresponding word in the British-english dictionary. Any language dictionary may be substituted for both or either dictionary, and any number of dictionaries may be included. Preferably, however, both dictionaries include at least one identical entry, such as the word "the", so as to facilitate checking whether the dictionary ROM is connected, as described more fully below. A suitable dictionary for use in ROM 42 is the spelling verifier database available from Houghton-Mifflin. Both dictionaries can be stored on the same physical ROM, such as a one megabit Toshiba TC571000D. In the present embodiment, each such dictionary requires approximately 512 kilobits of storage within the ROM. One half the ROM is dedicated to the American-english dictionary and the other half is dedicated to the British-english dictionary. With such an arrangement, 16 bits are required to address one word in both dictionaries (bits A0 through A15). A seventeenth address bit, A16 which is the most significant bit, is used to select which dictionary is accessed and, consequentially, which dictionary returns data to the microprocessor. For example, if the 17th bit is set to "0", then the American-english dictionary is selected. On the other hand, if the 17th bit is set to "1", then the British-english dictionary is selected. The most significant bit is controlled by port 34 of microprocessor 32 and is selected by the key sequence CODE + 0. Microprocessor 32 includes dedicated interface port 21 for communicating with keyboard 2, and includes dedicated interface ports 23 and 25 for communicating with printer 30 and buzzer 28. Input print information from keyboard 2 as well as control operations are sent to microprocessor 32 through interface port 21. In accordance with the input print information and control operations, microprocessor 32 sends commands to printer 30 through interface ports 23 and 25 to print input characters. Microprocessor 32 also sends signals through ports 23 and 25 to buzzer 28 in response to retrieved data from ROM 42 or in accordance with an operational function, such as end of line. Microprocessor 32 addresses dictionary ROM 42 through interface ports 27 and 31, with the most significant bit controlled by port 34, as described above. The interface ports are dedicated ports in that no other devices are connected to those ports and the ports are configured to communicate only with ROM 42. Port 27 of microprocessor 32 is also connected to the data lines of external dictionary ROM 42 so as to allow microprocessor 32 to access spelling information from external ROM 32. Microprocessor 32 in the illustrated embodiment is configured such that it can output information to only one of its eight interface ports at any one time. Accordingly, address latch 44 is provided to latch the eight least significant bits (A0 through A7) of the 17 bit address. Address latch 44 is connected to port 27 of microprocessor 32 and controlled by enable 29 of port 36. Address latch 44 temporarily stores the least 8 bits of the ROM address. When enable 29 is high, 8 bits sent from port 27 are latched into address latch 44. When enable 29 is low, the 8 bits from address latch 44 and 8 bits from port 27 (total of 16 bits) go to ROM address lines 41 and 43, respectively. The seventeenth bit (i.e., the dictionary selection bit) is provided from port 34. Once the address is sent to external ROM 42, output enable 45 is set so as to enable the spelling information data at the specified address to be read by the microprocessor 32 at port 27. Fig. 4 is a representation of a memory map of the internal RAM 38 of microprocessor 32. RAM 38 is used to store information regarding the current status of the operation functions of the electronic typewriter 2 such as print information. RAM 38 also stores flags that indicate whether the spell verification function has been enabled or disabled. In Fig. 4, there are three flag indicators that effect the behavior of the spell verifier function. Dictionary ROM-connected flag 50 indicates whether the electronic typewriter includes a dictionary ROM. In this manner, an electronic typewriter can be sold having the spell verifier function or the electronic typewriter can be sold without the spell verifier function. Current dictionary flag 52 indicates the current dictionary selected in accordance with CODE + 0 selection by the operator. Spell verifier on/off flag 54 indicates whether the spell verifier is enabled or disabled in accordance with CODE + 9 selection by the operator. By virtue of the stored flags, the microprocessor 32 can readily determine the status of the spell verification function. When the current dictionary flag 52 is clear (setting the flag to "0"), the American-english dictionary is selected, and when the current dictionary flag 52 is set (setting the flag to "1"), the British-english dictionary is selected. When the spell verifier on/off flag 54 is clear, the spell verifier is off and when the spell verifier on/off flag 54 is set, the spell verifier is on. The remaining portion illustrated in RAM 38 is dedicated as a word buffer 56. The word buffer 56 contains a word input and/or character strings input by the operator represented by print information in common ASCII codes. In operation, the program software detects an end of word or end of character string has been entered by the operator. End of word or character string is detected, for example, when an operator enters either a space character or a punctuation character or the "return" key. At power-up, microprocessor 32 performs a systems check which includes detecting whether external dictionary ROM 42 is connected to ports 29 and 31 of microprocessor 32. In accordance with this detection, dictionary ROM-connected flag 50 is set or cleared. Fig. 5 is a flow chart showing the power-up systems check steps. In step 80, microprocessor 32 retrieves from internal ROM 40 a predetermined word that is spelled identically in both dictionaries. For example, the word "color" could not be used as a predetermined word since "color" is spelled differently in the British-english dictionary. On the other hand, the word "the" is spelled identically in both dictionaries and if sent to either dictionary, regardless of which is selected, will be verified as correctly spelled. In step 81, the address of the predetermined word is sent to both dictionaries in dictionary ROM 42. In this step, the status of the seventeenth address bit A16, and consequently which of the two dictionaries is accessed, is immaterial because the predetermined word is spelled identically in both dictionaries. Step 82 checks if the ROM indicates that the predetermined word was spelled correctly. Since the predetermined word was selected so that it is correctly spelled in either dictionary, the only reason that the ROM would indicate an incorrect spelling is that the ROM is not connected. Accordingly, if step 82 determines that the word is spelled incorrectly, then flow advances to step 84 where the dictionary ROM-connected flag 50 is set to "0" in RAM 38. Thereafter, the program exits indicating that a dictionary ROM is not connected to interface ports 29 and 31 of microprocessor 32. That is, the electronic typewriter has been shipped without a spell verification function. On the other hand, if step 82 determines that the word was spelled correctly, then flow advances to step 86 where the dictionary ROM-connected flag 50 is set to "1" in RAM 38, indicating that dictionary ROM 42 is connected. Figure 6 is a flow chart of the spell verification function process. Upon power-up, the spell verification process checks the status of the dictionary ROM-connected flag 50 stored in RAM 38, as set by the flow process of Fig. 5, to determine if the dictionary ROM is connected in the electronic typewriter (step 60). In the case the dictionary ROM is not connected, the spell verification process immediately exits the spell verification program. In the case the dictionary ROM is connected, the spell verification procedure proceeds to step 62 to determine whether the spell verifier on/off flag 52 is set in RAM 38 thereby indicating if the spell verification is enabled or disabled in accordance with the operator selecting CODE + 9. In the case the spell verifier is enabled, the spell verification procedure computes a verify code in step 64 based on the current contents of word buffer 56 stored at RAM 38. The algorithm for computing the verify code and the format of the information in the dictionary database is known in the art; suitable algorithms are available from Houghton-Mifflin in connection with the above-described dictionary database. In step 66, the spell verification procedure computes the ROM address for dictionary ROM 42. In step 68, the data at that ROM address is retrieved and compared with the print information stored in RAM 38. The data retrieved from the selected portion of the dictionary ROM is then compared with the verify code computed in step 64 to determine if the spelling is acceptable as shown in step 70. In the case the spelling is correct, normal typing operation continues. However, in step 72, in the case the spelling of the word is unacceptable, an audible alarm is sounded by buzzer 28. Preferably, the audible alarm is distinctive so that an operator can readily distinguish between an alarm indicating improper spelling from other alarms such as alarms associated with typewriter functions (margin, etc.) and alarms associated with other typewriter errors.

Claims: A printing apparatus comprising: input means (2) for manually inputting print information; output means (30) for outputting print information; storage means (42) for storing at least one spelling information dictionary; and processing means (32) for controlling said output means (30) to output print information based on print information input by said input means (2) and for accessing said storage means (42) in accordance with print information input by said input means (2); characterised by address latching means (44) for latching address information from said processing means (32) to said storage means (42); in that said processing means (32) comprises a single chip microprocessor which has a first dedicated interface (23, 25) comprising a first multi-bit connection to said output means (30) for interfacing to said output means (30), a second dedicated interface (31) comprising a second multi-bit connection to said storage means (42), and a third dedicated interface (27) comprising a third multi-bit connection to said address latching means (32) for latching address information from said third dedicated interface (27) to said storage means (42) simultaneously with the delivery of address information from said second dedicated interface (31) to said storage means (42), said third dedicated interface (27) being further connected to said storage means (42) for receiving spelling information accessed from said storage means (42); in that said processing means (32) has internal program storage means (40) for storing program instructions for controlling said output means (30) to output the print information; in that said processing means (32) is operative to write a first part of address information through said second dedicated interface (31) to said storage means (42) and a second part of address information through said third dedicated interface (27) to said storage means; and in that said storage means (42) is operative to output the spelling information to said third dedicated interface (27) based on the first and second parts of address information. A printing apparatus according to claim 1, wherein said single chip microprocessor further comprises memory means (38) including random access memory for storing print information input by the input means (2), and wherein said internal program storage means (40) stores program instructions for controlling the microprocessor to access said storage means (42) based on the print information in said memory means (38). A printing apparatus according to claim 2, wherein said print information includes a character string, and wherein said processing means (32) includes detection means for detecting an end of the character string. A printing apparatus according to claim 3, wherein said processing means (32) is adapted to access said storage means (42) in response to an end of character string detection. A printing apparatus according to claim 4, wherein said processing means (32) is adapted to retrieve spelling information from said storage means (42) based on said access, and further comprising alarm means (28) responsive to retrieved spelling information. A printing apparatus according to claim 5, wherein the processing means (32) is adapted to sense plural operational conditions and to sound the alarm distinctively for different operational conditions. A printing apparatus according to claim 3, wherein said detection means (32) is adapted to detect an end of the character string in response to an input of a space or a punctuation by said input means (2). A printing apparatus according to claim 1, wherein said input means (2) is comprised by a keyboard. A printing apparatus according to claim 8, wherein said keyboard includes control keys for controlling operational modes. A printing apparatus according to claim 9, wherein said control keys are adapted to disable/enable a spell verify operational function. A printing apparatus according to claim 1, wherein said output means (30) comprises a relatively movable print carriage and platen controlled by said processing means (32), and said internal program storage means (40) stores program instructions for controlling the microprocessor to control relative movement of said carriage and said platen. A printing apparatus according to claim 11, wherein said output means (30) includes a daisy wheel (20), a hammer (22), a carriage motor (24), and a ribbon motor (26). A printing apparatus according to claim 1, wherein said output means (30) comprises one of a bubble jet printer, an ink jet printer or a thermal transfer printer. A printing apparatus according to claim 1 wherein said input means (2) comprises a keyboard for manually inputting a character string and for selecting a mode of operation; said output means (30) comprises a printer for printing the input character string; said storage means (42) comprises an external memory accessible in accordance with a multi-bit address and for storing more than one spelling information dictionary; and said processing means comprises a microprocessor including a random access memory (38) and a fourth dedicated interface (34) comprising a fourth multi-bit connection to the external memory; wherein said internal program storage means (40) comprises a read-only memory, said microprocessor is adapted to control the output of the printer in accordance with said input character string and to access the external memory in accordance with said input character string, said microprocessor is adapted to write one bit of address information through said fourth dedicated interface (34) to the external memory (42) in order to select one of the spelling information dictionaries, and said third dedicated interface (27) is adapted to receive the spelling information based additionally on the selected spelling information dictionary. A printing apparatus according to claim 14, wherein said printer comprises a daisy wheel motor (20), hammer (22), carriage motor (24), and ribbon motor (26). A printing apparatus according to claim 14, wherein said printer comprises one of a bubble jet printer, an ink jet printer, or a thermal transfer printer. A printing apparatus according to claim 14, wherein said read-only memory (40) stores program instructions for controlling said microprocessor (32) to control said printer (30) to output character strings input by said keyboard (2) and to access the external memory according to said input character string. A printing apparatus according to claim 14, wherein said random access memory (38) stores the character string input by the keyboard (2), and wherein said microprocessor is adapted to access the external memory (42) based on the character string in the random access memory (38). A printing apparatus according to claim 18, wherein said input character string includes character information, and wherein said microprocessor (32) includes detecting means for detecting an end of the character string. A printing apparatus according to claim 19, wherein said microprocessor (32) is adapted to access said external memory (42) in response to an end of character string detection. A printing apparatus according to claim 20, wherein said microprocessor (32) is adapted to retrieve spelling information based on said access, and further comprises alarm means (28) responsive to retrieved spelling information. A printing apparatus according to claim 21, wherein said microprocessor (32) is adapted to sense plural operational conditions and sounds the alarm distinctively. A printing apparatus according to claim 14, wherein said detection means is adapted to detect an end of the character string in response to said keyboard (2) inputting a space or a punctuation. A printing apparatus according to claim 14, wherein said keyboard (2) includes control keys for controlling operational modes. A printing apparatus according to claim 24, wherein the control keys are adapted to disable/enable a spell verify operational mode. A printing apparatus according to claim 14, wherein said printer (2) is comprised by relatively movable print carriage and platen controlled by said microprocessor (32), and wherein said read-only memory stores program instructions for controlling said microprocessor (32) to control relative movement. A printing apparatus according to claim 14, wherein the microprocessor has a selectably actuatable spell verification mode in which a character string input via said input means (2) is checked against the spelling information in a spelling information dictionary stored in said external memory (42), said microprocessor (32) including means for checking whether said spelling information dictionary is connected to said second to fourth dedicated interface (27,31,34) of said microprocessor (32), and wherein said microprocessor (32) is adapted to actuate the spell verification mode in a case that said spelling information dictionary is connected to the second to fourth dedicated interface and to disable the spell verification mode in the case that said spelling information dictionary is not connected to the second to fourth dedicated interface. A printing apparatus according to claim 27, wherein said means for checking is adapted to perform a power-up check to determine if said spelling information dictionary is connected to the second to fourth dedicated interface. A printing apparatus according to claim 28, wherein said microprocessor (32) is adapted to perform the power-up check by actuating the spell verification mode and by sending a predetermined character string to said spelling information dictionary. A printing apparatus according to claim 29, wherein said spelling information dictionary includes at least two different but complementary sets of spelling information. A printing apparatus according to claim 30, wherein the two sets of spelling information both include entries for the predetermined character string. A printing apparatus according to claim 1, wherein said storage means (42) includes a single read-only memory storing plural spelling information dictionaries; the apparatus further comprises designation means for manually designating one of the plural dictionaries; and said processing means (32) is adapted to select one of the plural dictionaries via a fourth dedicated interface (34) comprising a fourth multi-bit connection to said storage means (42), in accordance with the designation by the manual designation means. A printing apparatus according to claim 32, wherein the print information comprises character information. A printing apparatus according to claim 33, wherein said input means and said designation means are comprised by a keyboard (2). A printing apparatus according to claim 34, wherein the designation means is adapted to designate one of the plural dictionaries via plural keystrokes of said keyboard (2). A printing apparatus according to claim 33, wherein said internal program storage means (40) comprises a random access memory (38) for storing a current designation and said input character information. A printing apparatus according to claim 36, wherein said processing means is adapted to access the storage means (42) based on the character information stored in the random access memory (38). A printing apparatus according to claim 37, wherein the character information includes character strings, and wherein said processing means (32) includes means for detecting an end of the character strings. A printing apparatus according to claim 38, wherein said processing means (32) is adapted to access said storage means (42) in response to an end of character string detection. A printing apparatus according to claim 39, wherein said processing means (32) is adapted to retrieve information stored in said storage means (42) based on said access, and further comprises alarm means responsive to retrieved spelling information from said storage means (42). A printing apparatus according to claim 40, wherein the processing means (32) is adapted to sense plural operational conditions and sounds the alarm distinctively. A printing apparatus according to claim 34, wherein said keyboard (2) includes control keys for controlling operational modes. A printing apparatus according to claim 42, wherein the control keys are adapted to disable/enable a spell verify operational mode. A printing apparatus according to claim 32, wherein the output means (30) is comprised by relatively movable print carriage and platen controlled by said processing means (32) and wherein the internal program storage means stores program instructions for controlling said microprocessor (32) to control relative movement. A printing apparatus according to claim 44, wherein said output means (30) includes a daisy wheel (20), a hammer (22), a carriage motor (24), and a ribbon motor (26). A printing apparatus according to claim 44, wherein said output means (30) comprises one of a bubble jet printer, an ink jet printer, or a thermal transfer printer. A printing apparatus according to claim 32, wherein the plural dictionaries comprise two dictionaries stored in said single read-only memory (42), one dictionary stored in a first half and the other dictionary stored in a second half of said read only memory (42), and said processing means is adapted to select a designated dictionary by enabling or disabling a most significant address bit for said read-only memory. A printing method comprising the steps of: storing at least one spelling information dictionary in a storage means (42); inputting print information; and executing process steps so as to output print information input in said inputting step and so as to access stored spelling information from the stored spelling information dictionary in accordance with input print information; characterised in that the process steps are executed on a single chip microprocessor to control output of print information by sending commands using a first dedicated interface-(23, 25) comprising a first multi-bit connection to an output means (30), to access spelling information using a second dedicated interface (31) comprising a second multi-bit connection for delivering address information to said storage means, and to latch address information output to said storage means (42) from a third dedicated interface (27) comprising a third multi-bit connection using an address latch connected thereto simultaneously with the delivery of address information from the second dedicated interface (31) to said storage means (42), the third dedicated interface (27) also being connected to said storage means (42) for receiving spelling information accessed from said storage means (42); in order to access spelling information in said storage means (42), the microprocessor (32) writes a first part of address information through the second dedicated interface to said storage means (42) and a second part of address information through the third dedicated interface to said storage means (42); and spelling information is output from said storage means (42) to the third dedicated interface based on the first and second parts of address information. A method according to claim 48, further comprising the step of storing print information input in said inputting step in the single chip microprocessor and wherein said dictionary is accessed in accordance with the print information stored in said storing step. A method according to claim 49, further comprising the step of detecting an end of a character string in the print information. A method according to claim 50, wherein said dictionary is accessed in response to an end of character string detection. A method according to claim 51, further comprising the step of retrieving spelling information based on the dictionary access step and the step of actuating an alarm responsive to retrieved spelling information. A method according to claim 52, further comprising the step of sensing plural operational conditions and wherein the alarm is actuated distinctively for different operational conditions. A method according to claim 51, wherein said detecting step detects an end of character string in response to an input space or punctuation. A method according to claim 48, wherein the storing step stores plural dictionaries, and wherein the method further comprises the step of selecting one of the plural dictionaries. A method according to claim 48, wherein said inputting step is comprised by keyboard entry. A method according to claim 56, wherein said inputting step includes controlling operational modes from said keyboard entry. A method according to claim 57, wherein said step of controlling operational modes includes controlling a spell verify operational mode. A method according to claim 48, wherein said outputting step is comprised by relatively moving a print carriage and a platen and wherein the process steps include process steps to control relative movement of said carriage and said platen. A printing method according to claim 48, wherein the storage means (42) comprises an external memory which stores plural spelling information dictionaries, said external memory being accessible in accordance with a multi-bit address, and the output means (30) comprises a printer, and wherein the method further comprises the steps of: inputting a character string and selecting an operational mode by keyboard entry using a fourth dedicated interface (34) comprising a fourth multi-bit connection to the microprocessor (32); and printing a character string input by said inputting step in accordance with a command sent from the microprocessor (32) through the first dedicated interface connected to the printer. A method according to claim 48, further comprising the steps of: checking whether a dictionary of spelling information is connected to the second to fourth dedicated interface of a multi-bit connection which interface to the microprocessor (42); and selectably actuating a spell verification mode in which an input character string in the print information is compared with the spelling information in accordance with said checking step; wherein the spell verification mode is enabled in the case where said external dictionary is connected to the second to fourth dedicated interface and wherein the spell verification mode is disabled in the case where said dictionary is not connected to the second to fourth dedicated interface. A method according to claim 61, further comprising the step of detecting whether said dictionary is connected to the second to fourth dedicated interface of the microprocessor (32) during a power-up check. A method according to claim 62, wherein said detecting step includes performing the power-up check by actuating the spell verification mode and by sending a predetermined character string to said dictionary to determine if the dictionary is present. A method according to claim 63, further comprising the step of storing in the storage means (42) at least two dictionaries of different but complementary entries of spelling information. A method according to claim 64, wherein the at least two dictionaries have at least some of the same predetermined spelling information stored therein. A method according to claim 48, wherein the internal program memory (40) of the microprocessor comprises a read only memory; and the print information is input from a keyboard. A method according to claim 66, wherein at least two dictionaries are stored in said storage means (42), and the method further comprises a designating step for designating one of the dictionaries in said storage means (42). A method according to claim 67, wherein said designating step includes designating using said keyboard (2). A method according to claim 68, wherein said designating step is performed by plural keystrokes of said keyboard (2). A method according to claim 67, further comprising a step of storing a current designation and input character strings in a random access memory comprising the internal program memory of said microprocessor. A method according to claim 67, wherein said storing step includes storing character strings input in said inputting step, and wherein, in accordance with said designating step, said storage means (42) is accessed based on stored character strings. A method according to claim 71, further comprising the step of detecting an end of character string input in said inputting step. A method according to claim 72, wherein the storage means (42) comprises an external memory, and the method further comprises the step of accessing said external memory in response to an end of character string detection. A method according to claim 48, wherein the spelling information is accessed by retrieving information stored in said storage means (42) based on an input character string, and the method further comprises actuating an alarm in response to retrieved information. A method according to claim 74, wherein said actuating step includes actuating said alarm distinctively in response to respective plural operational conditions. A method according to claim 48, wherein said inputting step includes inputting operational modes by said keyboard (2). A method according to claim 76, wherein said inputting operational modes include disabling/enabling a spell verify operational mode. A method according to claim 48, further comprising the step of outputting character strings input in said inputting step. A method according to claim 78, wherein said outputting step includes relatively moving a print carriage and a platen controlled by said microprocessor and wherein the process steps control relative movement of the print carriage and the platen. A method according to claim 79, wherein said outputting step includes outputting to a daisy wheel (20), a hammer (22), a carriage motor (24), and a ribbon motor (26).

Inventors: CURREN JOHN M, UEDA HIROYUKI, CURREN, JOHN M., UEDA, HIROYUKI
Applicants: CANON BUSINESS MACHINES INC, CANON BUSINESS MACHINES, INC.
Application year: 1993
Main classification: G06F17
IPC codes: G06F17