JPS5927941B2 - electronic desk calculator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Conventionally, hexadecimal operations have been indispensable for engineers working on computers, especially system engineers, programmer, etc. The reality is that decimal calculations rely on written calculations or mental calculations, which often leads to miscalculations.

In view of this point, the present invention aims to realize a hexadecimal calculator by adding a changeover switch and simple logic to a conventional decimal calculator.

A detailed explanation will be added below according to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.

In the figure, R1 and R2 are data storage registers, ADRI is a hexadecimal adder usually called an adder, and ADR2 is usually a 10
An adder called a decimal correction circuit, 051 and 052 are one-shot generation circuits, SWI is a switch that specifies hexadecimal when turned to the left, and decimal when turned to the right, CONI and CON2 are ROM (read only memory) gates and flip-flops. Constant generation and conversion circuits G1 and G2 consisting of
, G33G4 is an AND gate, ORI is an OR gate, K
EY has the function of receiving key signals from keyboard KB and encoding them. More specifically, it selects numeric keys (including hexadecimal keys, decimal point keys, etc.), encodes them, and stores them in R1. It determines the means and calculation keys. The input control section DIS is a control for displaying or printing the contents of R2 at the output section D.

Figure 2 is an example of a circuit when CONI in Figure 1 is configured as a matrix; IN in the figure is a 2-digit decimal input line;
1 to F80 are series-in/para-out (serial input, parallel output) flip-flops that shift in synchronization with CPI.

IF'1 to 1F'80 are inverters, the circles at the intersections of the matrices are the diodes shown in the figure, (or MOS gates) F'1 to F'80 are parallel-line, series-out (parallel input, series output) flip-flops. Shift is performed in synchronization with CP2. In the above configuration, for example, 10
When 99 in decimal is entered, 1001 is entered in F1 to F80 respectively.
It is stored as 1001, and due to the matrix, only the input of 199 becomes 1, and at the same time, the output of 199 becomes o. From this, only the inputs of IF'8O, IF'4O, IF'2, and [F'1 become 0, and are inverted by the inverter, F1=F2=
F' 40■ F' 80=1, F' 4■ F'
8 ■ F'10 = F'20 = 0, which is O at CP2.
When led to UT, hexadecimal number C3 is output.

FIG. 3 illustrates CON2 using a matrix circuit similar to that shown in FIG.
11・1111) is entered, the 10th grade is 255 from 0UT.
(1001010101) is output. The circuit operation will be explained below using some examples.

Example 1) In Example 1), SWl is first set to hexadecimal, and when (5) is set, 5 is stored in R1, and by the next field, R1 and R2 are set to A.
Since R2 is 0, 5+O-5 is AD
It is output from Rl.

At this time, since SWl is set to hexadecimal, GlO
By FFG2ON, AD without going around the correction circuit ADR2.
The output of Rl is stored in R2 via G2 and ORl. Next, when you press the (7) key, 7 is stored in R1, and the mouth key executes R1 (7) + R2 (5) with ADRl, and the result is G.
2, stored in R2 via ORl, hexadecimal 1100 (C
code).

R2 is led to DIS, and the C code is displayed or printed.

In this way, calculations between hexadecimal numbers can be easily realized without using the conventional decimal correction circuit. Example 2) sets the SW to hexadecimal, and when a digit is set, it is stored in R1.If the SW is then set to decimal, the one-shot circuit operates at the moment the pulse rises or the reset switch is turned on. Then 0S2 works and the contents of R1 become G
4 to CON2.

CON2 has a hexadecimal to decimal conversion function as described above, and converts the A code to 10 and stores it in R1. That is, the code 1010 is converted to 10000.

Next, 10 is stored in R2 by pressing the key, and 10 is stored in R2 by pressing the key.
2 is stored in 1 and 10+2=12 is AD with the last key
Since SWl output from Rl is set to decimal, it is guided to the correction circuit via G1 and stored in R2 via 0R1.

Example 3) sets SWl to decimal, and after n is input, SWl is set to 1.
When set to hexadecimal, 0S1 works and R1 becomes CONl and G3
, where decimal-to-hexadecimal conversion is performed as described above.

Example 3) happens to be an example of a single decimal digit, but even if decimal 15 is led to CONl, it becomes a hexadecimal F code. Since 9 in decimal is also 9 in hexadecimal, 9 (1001) is stored in R1 again and converted to 9+0-4 by Goda.
9 is stored in R2, the next E position stores the B code in R1, the last entry executes B+9 in ADRl,
The result is stored in R2 via G2 and is the hexadecimal answer 14
get.

As explained above, the switch SWl performs decimal operation,
In addition to specifying hexadecimal calculations, it is also possible to perform calculations on data in different decimal numbers by switching the switch during the calculation.

Furthermore, even when only converting the data into a base number without performing calculations, the CONTLOL section may be used to guide the contents of R1 to the display. In addition, in the three examples above, the conversion was performed by operating the changeover switch immediately after the input number, but it can also be operated immediately after pressing the calculation key, either by leading R2 to the conversion circuit or by inputting the next input number. This can be easily achieved by first selecting a method of transferring data from R1 to R2.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIGS. 2 and 3 are detailed diagrams of CON1 and CON2 in FIG. 1.

Claims (1)

[Claims] 1 a register for storing data, a hexadecimal adder to which data from the register is applied, a decimal correction circuit, and a 10
An electronic desktop calculator comprising: a switch for manually specifying decimal and hexadecimal; and circuit means for selecting whether or not to use the decimal correction circuit according to the specification of the switch.