VU-Calc

Sinclair

ZX Spectrum with 16K or

48K RAM



VU-CALC

from PSION



Load and Run by typing LOAD "VU-CALC"



Pocket calculators have become a powerful and

indispensable tool to many, though they only work out

and display one number at a time. They are useful

because there are many things in life that are well

described by a single number. There are many more

things, however, which can be described more fully and

completely with a table or an array of numbers

organised in an ordered way. VU-CALC is a program for

calculating and displaying tables of numbers and

names. You start with an empty table or grid composed

of boxes and arranged in rows and columns. With a

simple set of commands you can invoke calculator-like

formulae which link one box to another or one row to

another or one column to another so that the computer

can calculate a whole table in a few seconds. You can

also enter data or names into particular boxes and by

simply changing one or more parameters, tables for

different situations can be re-evaluated and displayed

almost immediately.



This provides an immensely powerful tool for financial

analysis, budgets, the calculation of engineering or

scientific tables, statistical analysis etc.



LAYOUT Table, Cursor and Window

On entering VU-CALC, a two-line command panel can

be seen at the top of the screen, a blank labelled area is

in the middle of the screen and an input line can be seen

at the bottom of the screen. The blank area in the

middle of the screen is a window onto the table.

The table can be thought of as a large number of boxes

ordered into rows or columns. The rows are labelled

alphabetically and the current rows shown in the

window can be seen down the left-hand margin.

The columns are labelled numerically from 01 upwards

and the current columns shown in the window are

numbered along the line immediately above the

window. Each box or rectangle is uniquely identified by

the row letter followed by the column number.

Thus, A01 or A1 refers to the box lying in the top

left-hand corner of the table.



At any stage during the use of VU-CALC, the user's

attention relates to a particular box which is illustrated

as a large red rectangle on the table. This is the cursor.

The cursor can be moved freely and rapidly to read or

enter data, text or formulae. The cursor is moved on the

table by pressing the four arrow cursor keys on the

keyboard, (caps shift held down while keys 5, 6, 7 or 8

are pressed). The cursor may be moved rapidly by

holding down one of the arrow keys firmly.

When the cursor reaches a box at the edge of the

window and the cursor keys are pressed further the

window will automatically move over the table. This can

be observed by noticing the column numbers or row

numbers along the sides of the window changing.

By this means, the user can move rapidly round a very

large table (in the case of the 48K Spectrum).



Entering Data and Text

The user may think of VU-CALC as a thinking spread-

sheet in which he may layout at will text and numerical

data. At the main command point of VU-CALC, 4 types

of entries may be made: text, data, formulae or a

command.



To enter text, position the cursor at the box where you

wish to start the text. Press " and now simply type in

the text which you wish to enter at that position. As you

type you will see the text being written on the input line

at the bottom of the screen with the small red cursor on

that line moving along. You may fill the whole line and

use the delete key to make alterations. When complete,

press "ENTER" to insert the text onto the spread-sheet.



To enter a number in any box, simply position the cursor

where you wish to enter the number and type in the

number followed by the "ENTER" key. The number will

immediately be shown in the current box.



To calculate a number at a particular box using a

formula, position the cursor at the appropriate box and

simply type in the formula. When the formula as shown

on the bottom input line is correct press "ENTER"

which will apply the formula to the current box and

which will calculate the data immediately at the

appropriate boxes. A formula may be applied to many

boxes with the # Repeat command; VU-CALC will

automatically distinguish between text, data and

formulae.



When the bottom input line is empty, typing a "#" will

set VU-CALC into the command mode and a list of

commands will appear on the top two lines. By pressing

the first character of the required command, the

command will be executed subject to its appropriate

parameters.



Formulae

The real power of VU-CALC comes from the use of

formulae for boxes, rows or columns which can

generate the data you require for your tables. The syntax

of a formula includes the use of constants (numbers),

references to the numbers in other boxes and the simple

arithmetical operators: +, -, /, *. The numbers in

another box are always referred to by the box reference

of row letter followed by column number.



In constructing formulae you may think of the box

references as variables and the formulae as simple

algebraic expressions using these variables, constants

and the arithmetical operators. Some examples of such

formulae are: -

B1*1.03

D12*(B2+1.5)/C1

D7-C7

A formula can refer to one particular box or it may be

repeated along a row, down a column, or across a

block. To achieve this, the # Repeat command is used

(see below under commands).



Formulae are always applied relatively. For example, in

the Repeat command, if the current formula is being

applied to a sequence of boxes along a row then the

column references in the formula are always

incremented as the formula is applied sequentially along

the row. For example, if the formula "1.03*A1" in the

box A2 was repeated along the row A then the formula

in box A3 would be "1.03*A2" and the formula in box

A4 would be "1.03*A3'; etc. The same relative

concept is applied down a column or over a block where

the row letters in the formula are incremented

sequentially.



If, in a formula, you wish to refer to an absolute box

reference which does not alter when repeated, the box

reference in the formula should be prefixed with the

character "$". Thus, for the above example, the formula

"1.03*$A1" when applied to the row A would always

refer to the contents of box A1 only.



COMMANDS

A variety of commands exist in VU-CALC for loading,

saving and printing files, for editing etc. These

commands are entered by typing "#" in the empty

input line followed by the first character of the particular

command.



# B Blank

Blanks the current box.



# C Calculate

Forces a recalculation of the whole table and is

sometimes required when a formula is changed.



# E Edit

Allows the formula referred to by the current box to be

replaced by a new formula.



# F,c,f,j Format

Format specifies the representation of a number in a

column, as defined by the three parameters c,f,j.

The first parameter c must be a one or two digit number

or the letter "A". If c is a number, the formatting will

apply to that column only, while "A" will apply the

format to All the table.

The parameter f specifies the type of formatting

required. If an I is entered, integer format will be used.

If $ ix entered, a real number with two decimal points

will be used. G specifies a general format. The third

parameter, j, must be L or R for left or right justified.



# G,rc Go

Move the cursor immediately to the box rc.



# L Load

Will clear the screen, ask for a file name and load

that file.



# P Print

Will cause a copy of the screen to be output to

the printer.



# Q Quit

Will allow the user to clear the worksheet or exit from

the program.



# R,rc,f:l Repeat

This will cause the contents of the box rc to be

reproduced across the range specified. Most

importantly, it will repeat the formula in the box rc

over the other boxes within the range specified.

The first parameter, rc, is a box reference, for example

B3, which specifies the box whose contents or formula

is to be repeated.

The box can be repeated along a row, down a column or

over a rectangular block of boxes. This is defined by the

parameter range which has the form f:l where f and l

are box references, for example A3:B5. f is the top left-

hand box of the block and l is the bottom right-hand

box of the block. In the example, the box at rrcc would

be repeated over the boxes A3, A4, A5, B3, B4 and B5,

in the range, the box f must always be to the left, and,

or above the box l.



# S Save

Clears the screen and asks the user for a file name.

The data on the table will be saved to cassette.



# T,r or c,r or c Transfer

This command transfers a row or column defined by the

first parameter to another row or column defined by the

second parameter. A row cannot be copied to a column

and vice-versa.



SUM FACILITY

Part of a row, a column, or a rectangular block of

boxes way be added automatically through the sum

facility. Summing is performed as a formula. Position

the cursor at the cell where you wish to place the

result of the summation. Enter a formula of the form

& f:l

and press the enter key. The sign "&" means sum and

the formula means "sum the boxes from the first box f

to the last box l".

f: l is the rectangular "range" of boxes over which the

summation is to be performed where f is the top left-

hand box of the rectangle. For example:

& A2:B4

will sum the boxes A2 + A3 + A4 + B2 + B3 + B4.

To sum the row C from C3 to C10 enter,

& C3:C10

To sum the column 5 from B5 to D5 enter,

& B55

The box reference f must always be above and, or to

the left of box reference l.



Errors

An error will occur and the program will fail with a

Spectrum error code at the bottom of the screen if a

formula is entered which refers to a blank box or one

with characters rather than numerical data.

If this occurs, return to the program by entering GOTO

9000. The program will then display the identity of the

box which it was trying to calculate when the error

occurred. Press the key ENTER. The display will return

to the table and you may then move the cursor to the

problem square. Look at the formula for this box and

see which box the formula is referencing which

contains characters or is blank.





SUMMARY OF VU-CALC COMMANDS

# B - Blanks the current box and its formula.

# C - Forces recalculation of whole grid - required when data or a formula

is changed.

# E - To change the formula in the current box.

# F,c,f,j - Formats column c (A=All), f=I (integer), =$ (decimal),

=G (general), j=L (left), = R (right) justified.

# G,rc - Go to box rc.

# L - Load a Vu-Calc data file.

# P - Prints a copy of the screen.

# Q - Quits Vu-Calc.

# R,rc,f:l - Repeat contents of box rc over range of boxes f to l.

# S - Saves the current Vu-Calc file.

# T,r or c,r' or c' - Transfer row r to row r' or column c to c'.





(c) Copyright PSION Ltd.

Made in U.K.