File deletion system in a file unit

Deletion of a particular message in a file unit is accomplished for those messages with deletion set code in a file directory displayed on a screen. Operation of the deletion of a message includes (a) depression of a "deletion" key for indicating a file directory on a screen, (b) designating messages to be deleted by depression of a deletion set/reset key to change a deletion set/reset code to a set code, and (c) execution of deletion by the depression of a "deletion execution" key to delete a message with said deletion set code. A file directory indicated on a screen includes a deletion set/reset code, a message number, nature of a message, length of a message, and first 60 characters of a message, which simplifies identification of a message to be deleted.

BACKGROUND OF THE INVENTION 
The present invention relates to a file deletion system which deletes 
designated messages in a file memory like a floppy disc. The present 
invention is useful in applying to a telex terminal, a word processor, 
and/or a personal computer. 
A conventional file deletion system is shown in FIG. 1A, in which KB shows 
a keyboard, CPU shows a programmed processor, CRT shows a cathode ray tube 
screen, File unit shows a file device like a floppy disc unit, the 
reference numeral 1 is alphabet keys for generation of a message, 2 is a 
reception unit which receives a message from a line, 3 is a file generator 
for generating a file which is to be stored in a file device (a floppy 
disc (FDD), or a random access memory (RAM), 4 is a screen for indicating 
input data and guidance information, 5 is a file unit having random access 
memory 5A for storing a file, and a floppy disc 5B for storing files, 7 is 
a deletion key for designating deletion of a file, 8 is a guidance display 
means for displaying guidance information on the screen 4, 9 is a set of 
numerical keys for designating the number of a file to be deleted, 10 is 
numerical display control for displaying numbers of files to be deleted, 
11 is an execution key for execution of deletion of the designated 
message, and 12 is deletion execution means for executing the deletion of 
a designated message on a RAM or a floppy disc. 
When a new message is provided by alphabet keys 1 or a reception unit 2, 
the file generator 3 designates an available file number, and input data 
is displayed on the screen 4. Then, the message is registered in the file 
unit with the designated file number. Thus, a plurality of files are 
generated in a file unit 5 (a floppy disc). 
When it is desired to delete a message on a file unit 5, an operator 
depresses a deletion key 7, then, the guidance display means 8 displays 
the guidance information on the screen 4. The example of the guidance 
information is shown in FIG. 1B. Then, the operator depresses the numeric 
keys to designate the number of the message to be deleted. That number is 
informed to the numeral display control 10, which displays the number of 
the message to be deleted on the screen 4. When a plurality of message are 
deleted simultaneously, a plurality of numbers are indicated as shown in 
FIG. 1B. After the numbers of the messages to be deleted are indicated on 
the screen 4, the operator depresses the execution key 11, then, the 
deletion of the designated messages is carried out. The deletion execution 
means 12 reads the number to be deleted indicated on the screen 4. 
Accordingly, the conventional file deletion system shown in FIGS. 1A and 1B 
has the disadvantages that the message is identified by merely the file 
number and therefore the operator must have a list of messages to check 
the message number and the content of the message, and incorrectly 
deleting a message which should not be erased occurs frequently. 
SUMMARY OF THE INVENTION 
It is an object, therefore, of the present invention to overcome the 
disadvantages and limitations of a prior file deletion system by providing 
a new and improved file deletion system. 
It is also an object of the present invention to provide a file deletion 
system which indicates not only a message number, but also part of the 
content of the message to be deleted. 
It is a further object of the present invention to provide a file deletion 
system which designates a message to be deleted not by a message number, 
but by a line of a message directory which shows the nature of the message 
in detail. 
The above and other objects are attained by a file deletion system for 
erasing a message in a file unit comprising a keyboard having at least a 
deletion key (7), a deletion set/reset key (7a), and execution key (11), 
cursor shift keys (13), and some alphanumerical keys; a file generator 
means for generating a file directory, wherein said file directory 
consists of a list of files containing at least said particular message; a 
display means for indicating said list of said file directory containing 
said particular message; file directory control means for indicating said 
list of said file directory on said display means upon depression of said 
deletion key (7), said file directory including at least a deletion 
set/reset code and an initial group of characters of each message 
reflecting the content of said message; a cursor control means for 
shifting a cursor up and down on said display means upon depression of 
said cursor shift keys (13), and indicating a cursor on said deletion 
set/reset code of a first message upon depression of said deletion key 
(7); a deletion set/reset control means for changing said set/reset code 
under the cursor upon depression of said deletion set/reset key (7a) 
between set code and reset code; a deletion execution means for deleting a 
message in said file unit designated by the file directory with deletion 
set code upon depression of said execution key (11).

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 2A shows a block diagram of the file deletion system which operates 
with a programmed computer, FIG. 2B shows an example of a display, FIG. 3 
shows an example of a display in detail, FIG. 4 shows a flow diagram of 
the operation of the present file deletion system, and FIG. 5 shows a 
block diagram of the present file deletion system which operates with 
hardware. 
In FIG. 2A, the numerals 1 through 7 show the same members as those of FIG. 
1A. The CPU (central processing unit) is programmed so that it has the 
following functions; a file directory display function 8 which displays a 
file directory of the file unit 5 on the screen 4 according to the 
depression of the deletion key 7; a cursor shift function 10 to shift a 
cursor on the screen according to the cursor shift keys 13 (an up key, and 
a down key); a deletion set/reset function 12 which sets or resets a 
deletion code on the screen 4 according to the depression of the deletion 
key 7a; an execution function 14 which executes the actual deletion of a 
designated message upon depression of the execution key 11; and a file 
generation function 3 which is the same as the conventional one on FIG. 
1A. 
The keyboard KB has the deletion key (DEL) 7, 7a for entering the file 
deletion operation, and sets/resets the deletion of the files, the cursor 
shift keys 13 (an up key, and a down key), an execution key 11 for the 
actual execution of the deletion. 
The deletion key 7a may double as the other deletion key 7. Of course, the 
keyboard KB has the alphabet keys (data keys) 1. 
When the particular message which is stored in the file unit 5 is to be 
deleted, an operator depresses the deletion key (DEL) 7, then, the file 
directory display function 8 displays the file directory of the messages 
stored in the file unit 5 (box 102 in FIG. 4). The format of the display 
is shown in FIG. 2B briefly, and is shown in detail in FIG. 3, in case of 
a telex terminal. 
In FIG. 2B, or FIG. 3, the first line (*FILE DIRECTORY -ALL) shows merely 
the title of the display. Each line of the display except the first line 
has the set/reset code (* or space). When that code is *, then, the 
message following the symbol * on the line is not deleted, and when that 
code is space, then, the message following the code is to be deleted by 
the next operation. That code (* or space) is changed alternately by 
depressing a deletion key 7a. The second term of the file directory (01, 
02, ---, 10) shows the file number. The next one bit code (P or S or R) 
shows the attribute or the nature of the message in case of a telex 
terminal, when the attribute code is "P", the message is the prepared 
message which is to be transmitted, when the code is "S", the message is 
the message which has been sent already, and when the code is "R", the 
message is the reception message). 
The next figures between the parenthesis show the file volume or the length 
of the message and how many lines the message has. The next code ":" is 
merely a separator on the screen. Following the separator ":", the first 
60 characters of the message are displayed. 
Accordingly, the file directory thus displayed according to the present 
invention gives the detailed information of the message as compared with 
that of the prior display of FIG. 1B, and an operator can recognize and 
identify the message only using the display. 
When the file directory is displayed, the cursor is located at the first 
line of the message, and at the extreme left column on the set/reset code 
as shown by the rectangular box in FIG. 2B. 
At the end of the file directory display, the code, (END) is displayed to 
show the end of the display (see FIG. 2B). 
Now, it is assumed that the message No. 03 which is the reception message, 
having 100 lines, with the initial characters (ABCDEFGHIJK---), is to be 
deleted. 
In that case, the operator depresses the down key (cursor shift key 13) 
twice so that the cursor shifts to the fourth line which shows the message 
(03) from the second line on which the cursor located (the operation is 
shown in FIG. 4 by the box 104, through the boxes 106, 108 to the box 
104). Then, the cursor shift function 10 (FIG. 2A) shifts the cursor by 
two lines downwards. 
Next, the operator depresses the deletion set/reset key (DEL) 7a, then, the 
deletion function 12 changes the set/reset code at the top of the fourth 
line from (*) to the space which indicates that the message is to be 
deleted. Designation of the deletion of a plurality of messages is 
possible by changing a plurality of (*) codes to the space codes. If the 
deletion key 7a is depressed again, the space code returns to (*) code 
which shows that the message is not to be deleted. Therefore, the 
depression of the deletion key 7a switches the message indicated by the 
cursor between the deletion message and the no-deletion message. The 
operation of the depression of the deletion key 7a is shown by the path 
with the boxes 104, 106 and 110 in FIG. 4. 
Next, the operator depresses the execution key 11, then, the execution 
function 14 executes the deletion of the messages which have the space 
code at the set/reset code location. In the present embodiment, the 
message 03 is deleted. After the completion of the deletion, the new file 
directory which does not include the deleted messages is displayed on the 
screen. The operation of the depression of the execution key 11 is shown 
by the path with the boxes 104, 106, 112, and 114 in FIG. 4. 
The above operation is carried out either by a programmed computer as shown 
in FIG. 2A, or a hardware configuration as shown in FIG. 5. In FIG. 5, the 
numeral 4 is a display, 4A is a display memory, 5 is a file unit, 13 is 
cursor shift keys (an up key and a down key), 200 is an address generator 
for providing address information to the file unit 5, 202 is a file 
directory display control, 204 is a deletion set/reset control, 206 is a 
deletion execution control, 208 is a read/write control for the file unit 
5, 210 is a set/reset sensor which detects if the set/reset code of each 
message in the file unit has the deletion code (space) or the non-deletion 
code (*), 212 is a read/write control for the display memory 4A, 214 is a 
cursor control for location of the cursor on the screen 4, according to 
the depression of the cursor shift keys 13. 
In operation, upon depression of the deletion key 7, the file directory 
display control 202 reads the file directory in the file unit, and the 
file directory thus read out is written in the display memory 4A, the 
content of which is displayed on the screen 4. The cursor is located at 
the left end of the first message as shown in FIG. 2B. 
Then, upon the depression of the cursor shift keys 13, the cursor shifts 
upward or downward. With the shift of the cursor, the address generator 
200 provides the address at which the message designated by the cursor is 
stored. 
Then, upon the depression of the deletion set/reset key 7a, the deletion 
set/reset control 204 substitutes the (*) code to the space, and 
substitutes the space to (*) code both in the file memory 5 and the 
display memory 4A. 
Next, upon depression of the execution key 11, the deletion execution 
control 206 deletes the messages with the deletion code (space) in the 
file unit 5. After the deletion of the message, the new file directory is 
displayed on the screen 4. 
Accordingly, it should be appreciated that the message to be deleted is 
indicated not only with the file number, but also with the initial 60 
characters of the file, and therefore, an operator can identify the 
message to be deleted. Also, the message to be deleted is designated by a 
set/reset code (*, or space) on each line. Therefore, the mistake of the 
designation of a deletion message is prevented. 
From the foregoing, it will now be apparent that a new and improved file 
deletion system has been found. It should be understood of course that the 
embodiments disclosed are merely illustrative and are not intended to 
limit the scope of the invention. Reference should be made to the appended 
claims, therefore, rather than the specification as indicating the scope 
of the invention.