The Indiscrete Calculator
By Stuart P. Roberts
General Sales Manager
In the scientific and technical communities, there continues to be a vast need for simple, easily-used calculating equipment to complement the use of large computers. The ideal calculator is easily learned and should be capable of being programmed for sophisticated calculations without special program training or computer languages. The scientist frequently shuns a second career as a computer programmer, yet has a need for solutions to his personal computations. To fill this void, the Wang 700 was developed.
The Wang 700 is another major contribution from the leader of electronic calculators. It is the first third-generation computing calculator, operating faster and having more capacity than any machine on the market. Consider these design features: all IC construction for reliability, an 8192 bit magnetic core memory for data program storage, a 40,000 bit Read-Only-Memory, a cassette tape transport for program recording, and an arithmetic and logic unit of microsecond speed.
The display consists of two rows of NIXIE-type display tubes exhibiting the X- and Y-registers. These provide a highly legible, long-life display which minimizes the chances for error, and lets you use the 700 all day without fatigue. Capacity: 12 significant digits with sign, 2-digit exponent with sign, floating decimal point within display capacity, and automatic scientific notation otherwise.
Data entry is via the proven "10-key" arrangement. The keys, 0, 1, ....., 9, and decimal point are used for entering a number into the X-Register. The SET EXP key changes the algebraic sign of X or of the exponent. The ubiquitous Pi can be easily found by a single keystroke. The CLEAR X key can be used to correct errors.
Basic arithmetic perations, +, -, X, ÷, sqr(x), 1/x, Log 10(x), Log e(x), ex, |x|, int(x), and Pi, take place in the X- and Y-registers simply and directly.
Speed of calculations on the Wang 700 is sensational: 300 microseconds for + and -, 3.0 milliseconds for X; and 3.5 milliseconds for ÷.
Special Function keys conveniently perform frequently used operations. These normally include: SIN, COS, TAN, ARCSIN, ARCCOS, ARCTAN, SINH, COSH, TANH, ARCSINH, ARCCOSH, ARCTANH, Polar and Rectangular conversions. To execute any of these unctions, simple touch the appropriate key. In a program, only one command is used. Approximate speed: 250 milliseconds. To provide maximum flexibility at minimum cost to the user, these special functions are loaded into the machine as library packages when the machine is furst turned on. Thus, a statistical user will normally use a different package.
Data storage consists of 120 full-length registers. All registers on the Wang 700 are easily addressed in the same manner. The STORE DIRECT or RECALL DIRECT keys are used.
Every register is an accumulator capable of +, -, X, and ÷. Appropriate operation keys are used. This is a unique Wang feature, proven to save many steps.
Array manipulations can be easily performed on the Wang 700 by the unique STORE INDIRECT and RECALL INDIRECT commands. This is a feature usually found only on large computers. Inversion of a 10x10 matrix is possible, as well as solutions to 10 simultaneous equations, to mention a few of the possibilities.
Programming the Wang 700 is the easiest yet. In the LEARN Mode, keystrokes are stored sequentially into the core memory. Maximum program length is 960 steps if all of the core is used.
Features include the unique SEARCH and MARK method of branching and identifying destinations. Decision commands consits of the following: IF X>Y, IF X=Y, IF X less than Y, and IF OVERFLOW. Finally, simple subrouting commands add convenience and power for the user.
The tape cassette records a program permanently. In the RECORD mode, indexing the TRANSFER key puts the program onto magnetic tape for later use. Each cassette has a capacity for 10 programs, each up to 960 steps long. To load a program into core, simply index TRANSFER with the machine in the LEARN mode.
Loading a program is automatically accomplished by the LOAD PROGRAM command. This operation can be given manually or from a program. Under program control, this machine automatically begins execution after loading.
Debugging for the mortal programmer is a simple matter on the Wang 700. There are four significant aids in this case. First, the program can be executed one step at a time. The user can easily follow the progress of the calculation. Second, the next step number and the corresponding program code an be displayed. When a wrong command is observed, it can be corrected before execution. Third, the Wang 700 can be set to any step to make a correction by using the RESET PC key. Fourth, keystrokes can be inserted or deleted. This is a unique feature of the Wang 700.
Three simple output commands are available when an output device, such as a typewriter, is connected to the system. The WRITE command is used to output a number from the X-Register. It must be followed by a second command to specify the number of digits to be printed before and after the decimal point. When compatible with the output device, the WRITE A instruction is used to print alphabetic data. A string of codes following WRITE A is printed; the string is terminated by an END WRITE command.
When a typwriter is available, the user can literally write his program on the Wang 700. By putting the machine in the LEARN-PRINT mode, the 700 automatically types out the program code for each keystroke as it is keyed into core - no chance for transcription errors.
The Wang 700 is a calculating machine designed for the scientific and engineering community. It will help you arrive at solutions faster.