JPS6141013B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data transfer method between an input/output device and a storage device, and more particularly to a data transfer termination method.

Conventionally, input/output control devices that control data transfer between input/output devices and storage devices store the amount of data to be transferred specified by a program in a counter or the like.
Each time data is exchanged with an input/output device, the contents of the counter, etc. are subtracted, and the contents of the counter, etc. are "0".
It was a method to detect the end of data transfer when this happens. Information processing devices that process data exchanged between input/output devices and storage devices generally use 8-bit unit codes as their internal codes, and input/output devices also process data exchanged with storage devices. It is an 8-bit unit code.

Data to an input/output device may be transmitted via a communication line, and it is common to transmit data using a 7-bit unit code on the communication line. If this transmission device could be applied to a data transfer device of an information processing system, it would be advantageous in terms of cost.
However, in this case, it is necessary to convert between a 7-bit unit code and an 8-bit unit code, and because this conversion is performed, conventional transfer control based on data amount becomes impossible.

For example, input of data from a paper card reading device (hereinafter referred to as a card league) is normally performed in units of paper cards, and an 8-unit code is used for paper cards. Card readers for data transfer over communication lines are configured to send data in 7-unit codes, and to differentiate the most significant bit of the 8-unit code, it changes to either a "1" or a "0". By inserting and transmitting a 7-unit shift-out code or shift-in code as a code indicating this using a card reader, the most significant bit of 8 units is omitted and the 7-unit code is transmitted. Therefore, by one paper card, Part 8
If the number of changes in the most significant bit of the unit is large, the number of shift-ins and shift-outs will increase, and the amount of data to be sent from one paper card will increase. However, the number of shift-ins and shift-outs varies depending on the data content of the entire card, and the amount of data per card becomes undefined. Therefore, it is not possible to send data using a transfer method that assumes a fixed amount of data.

In order to solve the above-mentioned drawbacks, this invention is a data transfer method in which the transfer is terminated when the data exchanged with the input/output device matches the contents of a register set in advance by a program, and will be explained in detail below with reference to the drawings. .

FIG. 1 shows an embodiment of the data transfer system according to the present invention, in which a card reader 1 converts information on a paper card into a 7-bit unit code and sends it out. The sent data is sent to the storage device 4 via the input data signal line 3 within the input/output control device 2. The input/output control device 2 includes a register 5 for storing data designated by a program, a circuit 6 for detecting coincidence or mismatch between the output of the register 5 and data input from the card reader 1, and a transfer control circuit 7. ing. The card reader 1 and the transfer control circuit 7 are connected through a control tag line 8, and the transfer control circuit 7 and the storage device 4 are connected through a control tag line 9.
The transfer control circuit 7 controls the tag lines 8 and 9 based on the coincidence and non-coincidence outputs from the circuit 6. FIG. 2 is an example showing the order in which the card reader converts information on a paper card into a 7-bit unit code and outputs the code.

When the card reader reads the second hole position information (A) on the paper card, it reads the first information (A).
Since the most significant bit of the 8-bit unit code changes from "0" to "1", the shift out code 0001110 of the 7-unit code is sent, and then the second information (a) on the paper card is sent. Sends information on a 7-unit code with the most significant bit removed. Similarly, when reading the third information (B) on the paper card, the most significant bit changes from "1" to "0" in the second information (A) and the 8-bit unit code. The shift-in code 0001111 of the 7-unit code is sent out, and then the information of the 7-unit code with the most significant bit of the third information (B) on the paper card deleted is sent out.

Now, when the program sets the end code of the card reader in the register 5 in FIG. 1 and instructs to read a paper card punched with the information shown in FIG. 2, the following operations are performed.

(1) The transfer control circuit 7 controls the tag line 8 and instructs the card reader 1 to send data.

(2) Upon receiving the data transmission instruction, the card reader 1 converts the information on the first punch position of the paper card and transmits it.

(3) The match/mismatch detection circuit 6 compares the data set in the register 5 and the data input from the card reader 1. As shown in FIG. 2, since the data first sent from the card reader is not an NL code, the match/mismatch detection circuit 6 outputs a message indicating a mismatch.

(4) Upon receiving the output indicating the mismatch, the transfer control circuit 7 controls the tag line 8 and instructs the transmission of the next data.

(5) After the card reader 1 sends the Z code with the last paper card hole position, the above (2), (3), and (4) are performed until the card reader 1 sends the end code (LF code in Figure 2). ) action is repeated.

(6) When the end code is sent from the card reader 1, the match/mismatch detection circuit 6 outputs a match.

(7) Transfer control circuit 7 receives the output indicating a match
does not instruct the card reader to send data by controlling the tag line 8, and does not start controlling the tag line 8 until an instruction is received from the program.

In FIG. 2, the second and fourth codes to be sent are shift-out and shift-in codes, and the more such codes there are, the more the number of data to be sent will be than the 80 pieces of data on one paper card.

Since this data transfer method is used, it can be applied not only to the input device described above but also to an output device, and can also be applied to an input/output device using an 8-bit unit code.
It is possible to provide a data transfer method that does not depend on codes exchanged with input/output devices. Note that the card reader is configured to send an end code when it has finished sending data for one paper card. Although the code indicating this termination differs depending on the input/output device, the code indicating the termination is stored in the register 5 by an instruction.

As explained above, according to the present invention, 7-bit data transfer can be performed using 8-bit and 7-bit conversion performed on a communication line, and an information processing device can be manufactured at low cost. Moreover, information processing equipment is generally equipped with various input/output devices such as card readers, keyboards, printers, and displays, and these data end codes are LF.
Various codes are used, such as ETB code and ETX code. However, since the data transfer is completed by matching the data instructed by the program with the data sent and received by the input/output device, one block of input/output information, such as data for one card in a card reader, keyboard, etc. When the data for one line of a printer or display is undefined, there is an advantage that the program can instruct data input/output without being aware of the amount of input/output data.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of a data transfer device according to the present invention, and Fig. 2 shows the correspondence between perforation information on a paper card and data sent out by a card reader that converts it into a 7-unit code (JIS code). It is a figure illustrated. 1... Card reader, 2... Input/output control device, 3...
Input data signal line, 4...Storage device, 5...Register, 6...Coincidence/mismatch detection circuit, 7...Transfer control circuit, 8, 9...Tag line.

Claims (1)

[Claims] 1 In a data transfer method between an input/output device and a storage device, the most significant bit of data in an 8-bit unit code is removed to create a 7-bit unit code, and the most significant bit changes from “0” to “1”. Insert a shift-out code in units of 7 bits just before the most significant bit changes from "1" to "0", insert a shift-in code in units of 7 bits immediately before the most significant bit changes from "1" to "0",
A data transfer method that attaches an end code to the end of data and transfers it between an input/output device and a storage device, which includes a register to store the data and arbitrary end code data set in the register according to instructions from the program. means for detecting a match or mismatch between data transferred to and received from the input/output device and the contents of the register; and means for detecting a match between the transferred data and the contents of the register when data is transferred to and from the input/output device; and means for terminating data transfer with the input/output device.