CalcWrite 8.0

The Write-On Calculator for PalmOS®

Users Guide

Copyright (©) 2001 - 2002 Revelation Computing Pty Limited, Brisbane Australia
email: revcom@powerup.com.au


Introduction

Thank you for using CalcWrite! CalcWrite is an exciting new advance in computerised calculators. Writing with a pen on a sheet of paper is a very powerful experience. You can write any size, any where and in any order. You can mix text and numbers and draw diagrams all without changing writing implements. Shouldn't computers make life easier, not harder? Why can't we just add diagrams anywhere in our email messages, or easily sign our names at the bottom of our word processed letters?

Steven Levy in his book "Insanely Great" says:

"Compare this ... to a piece of paper, the world's greatest interface. No modes whatsoever. You write text, you doodle, you cross things out ... quite literally a tabula rasa. But just try to get a computer to be as flexible as a piece of paper, and very quickly you understand that thousands of dollars' worth of silicon and design genius gets lapped very quickly by one sheet of twenty-pound bond."

Why should computerised calculators just mimic the real world variety with simulated push buttons and a single line display? Can't we do much better than that in the new millennium? Maybe you can't do any better on a PC where you are generally limited to using a keyboard, but what about handheld devices that you can write on with a pen?

CalcWrite is a calculator whose metaphor goes way beyond the simulated push button calculator implemented on just about every computer system around.. CalcWrite makes calculation as easy as scribbling down some numbers on a sheet of paper. Literally.

Jot down a column of numbers on the Palm screen using the familiar graffiti strokes. Some digits (eg 4) will take extra strokes if desired. Draw a horizontal line underneath that column of numbers. (See left). Voila, as if by magic, the total of the column (62) appears beneath the line you drew. (If no operators are entered, CalcWrite assumes addition).

Go back and draw a subtraction sign (-) to the right of the second number. . A new result (52) is computed instantly to reflect the changed calculation the moment you lift the pen. (See example to the right). Note carefully that all operators in CalcWrite are written naturally, without having to use any Graffiti.

 

Write another number beneath the total (13 below 52 in our example) that CalcWrite has just computed. If you have the registered version, the screen scrolls to make space for more entries. (If not, just scroll using the up arrow button). Draw another line under the 13 and the new result (65) appears. With CalcWrite, you can turn a previous total into a subtotal to continue your calculations.

In the graffiti area of your Palm, draw a long backspace (a horizontal line from right to left), across the entire area (numeric -> alphabetic) to clear the entire calculation from the screen.

CalcWrite allows you to write numbers anywhere on the screen, in any order (even right to left if you want). The graffiti digits have even been enhanced a little to make handwritten entry a bit more natural. Add extra digits to the screen at any time. You can even drag existing digits anywhere on the screen to make room or alter the calculation. Change any operator (or number) at will and recalculate (see right) to perform 'what ifs'. Want to work with more numbers than will fit on the screen? Just scroll using the page up and down arrow buttons. Or CalcWrite can automatically scroll for you when you get too close to the bottom of the screen. (Registered version only).

I bet you just can't wait to show CalcWrite off to your friends, or to impress the boss!

That's CalcWrite in a nutshell - the scrolling, free form pen-driven calculator technology you would expect to find in the new millennium. Once you've tried it, you may never want to go back to pushing buttons again. Most Palm applications are merely "pen assisted" - they can't wait to turn your handwritten input into printed text at the first opportunity. CalcWrite is a totally new "pen powered" application - one that works with your very own handwritten numbers exactly when and where they were entered.


Table of Contents

Introduction Table of Contents Compatibility Installation Accuracy Getting Started
Entering Data Entering Calculations Order of Entry Methods of Entry Entering Numbers Entering Decimals
Guiding Boxes Entering Operators Selecting and Editing Digits Precedence and Brackets Clearing selected entries from the Screen Scrolling the Screen
Computing Results Using Results in Further Calculations Reworking a Previous Calculation Preferences Menus Bugs
HandEra 330 Support Known Deficiencies in CalcWrite Error Messages The Future

Compatibility

CalcWrite works on all Palm devices that run PalmOS 2.0 or later. That is, all released Palms starting with the PalmPilot Personal and PalmPilot Professional to the present day models. (At time of writing, PalmOS 4.0 is the latest operating system tested with CalcWrite). CalcWrite is around 68K in size and doesn't require very much free memory to run. CalcWrite does currently supports colour Palms but only in black and white. Please report any compatibility problems with your particular Palm model. Version 3.0 also supported the jog wheel found on Sony Clie devices. Version 5.0 supported the addtional screen size and rotation modes of the HandEra 330.

CalcWrite may not becompatible with 3rd party input software like TealScript or CIC's Jot. You may need to disable these in order to use CalcWrite. If you have any conflicting HackMaster hacks installed, you will be warned when you start CalcWrite. You should then exit immediately and disable the hacks. Or you can proceed to use CalcWrite with the hacks still enabled, to see if there is any noticeable effect. If the startup warnings annoy you, they can be turned off.

If you use TealMaster (instead of HackMaster) it gives you the option of enabling hacks only on a per-application basis, which some users find more convenient. Thus you can turn a hack off whilst using CalcWrite and on again when using all other applications.

CalcWrite will run whilst Art's simpliWrite software is enabled, although CalcWrite still interprets the standard graffiti numeric strokes, not the enhanced simpliWrite digits.

When upgrading CalcWrite to version 8.0, be sure to delete any old version of CalcWrite from your handheld BEFORE installing the new one. Failure to do this may result in weird preference settings or even a crash. Version 8.0 will automatically recognise if an old version hasn't been deleted properly and notify you that it has been deleted.

Installation

To install CalcWrite, open "CalcWrite.prc" using the Palm Install Tool. Add "CalcWrite Demo.pdb" to the list of files to be installed. (See above) Then, the next time you HotSync, both CalcWrite and its demo database should be successfully installed on your Palm device.

Tap on the CalcWrite icon in your handheld's launcher to run CalcWrite. If you see a conflict warning screen similar to that shown at the right, you have one or more HackMaster 'hacks' installed that will probably prevent CalcWrite from working correctly.

The safest option is to immediately click 'Exit' and then run HackMaster to turn off the offending hacks before restarting CalcWrite.

If you click 'Proceed -I'll risk it' CalcWrite will attempt to run with your hacks still installed. There shouldn't be any disasterous effects, but CalcWrite will probably have trouble recognising your handwritten digits and operators correctly. You will most likely see messages like: "Unrecognised graffiti symbol" when you try to write on the screen. Use the 'Proceed -I'll risk it' option to assess the impact of your set of installed hacks on the normal operation of CalcWrite. If everything seems to work, you can run CalcWrite with the hacks still installed.

If you uncheck the 'Warn me each time' option, this warning will not be shown again, even if conflicting hacks are discovered. You will need to use the User Preferences "Report conflicting hacks at start" option to turn the warning back on again.

CalcWrite's splash screen (see left) gives the option of runing a short animated demo to show the progran's capabilities (click 'Demo' button) or performing your own calculations straight away (click 'OK' button). This demonstration may flash several messages at the bottom of the screen to document the program feature it is about to use. A user preference allows this splash screen to be bypassed on startup if desired. (The 'r' after the version number signifies that this is the registered version).


Accuracy

CalcWrite internally uses 64 bit floating point numbers allowing numbers containing up to 8 significant digits before the decimal point, like most calculators. Final or intermediate results larger than 8 digits will cause an error 'e' to be displayed instead of a calculated result.

CalcWrite's accuracy is directly related to the care you take in writing and placing your numbers on the screen.

CalcWrite is only as accurate as your numeric graffiti. If you have found graffiti frustrating as an input method because of your handwriting style, you may find CalcWrite equally frustrating.

CalcWrite is extremely flexible in the input and placement of handwritten numbers on the screen. However, flexibility comes at some cost. CalcWrite attempts to make sense of whatever numbers you have written on the screen, where ever you have placed them. This can sometimes lead to mis-interpretation if you do not follow the few simple rules described in the rest of this document. Mis-interpretation of your numbers will almost certainly lead to a wrong result being computed for your calculation. If you are crunching the numbers for the 'deal of a lifetime' this may be to your distinct dis-advantage!.

Example 1: You may enter some numbers to add containing what looks like a correctly formed digit (6). The graffiti recogniser often sees a 'real world' digit 6 as the digit 4. This is not graffiti's fault. If you write accurate graffiti, according to Palm's rules, it will be correctly recognised. But if you are lazy and write a 6 that 'looks ok to you', you run the real risk of it being seen as a 4. The problem comes in that what appears on the screen is a 6 to your naked eye. (After all you wrote it). But CalcWrite will perform the calculation using not what you see, but what CalcWrite sees, that is, it will calculate using a 4 not a 6. So at least part of your calculation will be off by 2.

Example 2: If you write decimal points (or periods) near the bottom of the preceding digit, CalcWrite may see them as part of the number on the next line. This can lead to misinterpretation of the numbers on both lines, because one now has no decimal point and the other now has an added decimal. The rules below specify that you place decimal points around the centre of each line.

Example 3: If you write lines too close together, misgrouping of digits into numbers can occur. In the example on the right, the top of the '2' is too close to the bottom of the '3', so they are "seen" by CalcWrite as being part of the same number '32'.

To assist with solving these problems, CalcWrite automatically provides verification of each digit immediately it is entered, as well as the final calculation. CalcWrite also provides screen guidelines to assist you place each digit, operator or dot in a safe place. Be especially careful to allow enough space when adding new digits or moving existing ones, as CalcWrite can't always help you with guidelines in these cases.

You need to always carefully check the verification information that CalcWrite automatically provides for you as you enter numbers and perform calculations. Failure to do this can result in wrong results. You have been warned.

Remember, CalcWrite's results are only as accurate as the placement and accuracy (graffiti-wise)of your handwritten numbers. Checking only that what you have hand written on the screen is correct is definitely not enough. With a conventional calculator, careful users often check that you didn't inadvertently press the wrong button by quickly verifying the display entry after punching in each number. It is no different using CalcWrite.


Getting Started

CalcWrite's calculations are performed using numbers and operators entered anywhere on the Palm screen. Numbers are composed of digits and dots (also called decimal points or periods) substantially aligned horizontally. Significant variation in horizontal alignment can lead to digits being considered part of the number above or below it, so always follow the on screen guidelines.

Operators may be entered before or after complete numbers and operate on that number. Only one operator is permitted per number (apart from a leading - or +).

Digits and operators may comprise one or more strokes. Only one stroke is ever required, another may be added if desired. If the additional stroke is incorrect, or unrecognised, a dialog will appear (see left) indicating the strokes that are allowed for the particular digit or operator. Remember that additional strokes are not usually required, the correct symbol has probably already been recognised.

Brackets '(' and ')' may be used to group terms of the calculation together.

Calculations are triggered by the entry of a horizontal line(_____), or an equals sign (=) depending upon the layout of the calculation.

Upon exit, CalcWrite attempts to save all the terms and the result of the last calculation so they can be restored to the screen the next time CalcWrite is run. If the last calculation resulted in an error, the erroneous calculation will not be saved, instead the screen is simply cleared before exit.


Entering Data

Calculation data is entered into CalcWrite in the form of the digits (0 through 9), a decimal point (.), round brackets and operators (+, -, x, ÷, % and square root). CalcWrite does not currently support more advanced constructs involving fractions, powers or mathematical constants like pi or e.

Start entering numbers at the top of the screen, either to the left or around the centre, depending on the type of equation. As a general rule, proceed from left to right across the screen, and then from top to bottom down the screen. However you can always come back and add omitted digits or operators at a later time.

Digits and operators should always be spaced out across the screen. Some overlapping of symbols is now acceptable since version 3.0.


Entering Calculations on the Screen

Calculations can be entered in two ways, column style or equation style.

In column style, (see left) numbers are entered down the screen, one strictly below the other with a single operator to the right or left. A straight line (____) is drawn directly under the column to trigger calculation of the result. CalcWrite displays the result below the line and adds another parallel line beneath it (which is not selectable) to frame the result.

In equation style, (see right) numbers are entered across the screen with operators between each number. An equals sign (=) is entered to the right of the last figure to trigger the calculation of the result.

In equation style, you cannot split numbers across lines. The following layout is not permitted in equation style:

CalcWrite may sometimes accept a mixture of column and equation styles, but it is not recommended. Stick to one style or the other. Nor can you use any other style (like Reverse Polish for example). Do not use an equals sign (=) under a column of figures to trigger calculation of a result.


Order of Entry

Numbers can be entered anywhere on the screen. For column style, you usually start at the top of the screen in the centre or to the left. For equation style, start at the left hand side of the screen. There should always be (white) space between digits and digits or digits and operators, however the size of this space is not significant to CalcWrite.

Note carefully that when performing a calculation, CalcWrite always reads numbers from top to bottom and then from left to right as they are laid out on the screen, regardless of the order in which they were entered.

Numbers can be entered in any order. Normally, column style data is entered left to right, top to bottom. However numbers can be drawn in reverse order without any ill effects. For example, an omitted leading digit several lines above the current entry, could always be added later if desired. However, be sure to always leave sufficient space between the digits as guided by the boxes. (See "Guide Boxes", below).

Equation style numbers are usually entered from left to right but can be entered in any order provided there is room.

Do not try to cram numbers or digits too close together as this may cause them to be incorrectly recognised. This can lead to an incorrect result being calculated.

Remember that all marks on the screen are significant to CalcWrite. Even the most innocuous little spot may be interpreted as a decimal point by CalcWrite. Always select (by tapping) then erase any extra marks on the screen immediately by drawing a backspace (a horizontal line from right to left) across the numeric graffiti area.


Methods of Entry

CalcWrite supports several methods of entry for digits, decimals and operators.

The usual method of entry is drawing the digits, decimals and operators using the pen directly onto the screen using correctly formed graffiti strokes.

CalcWrite also implements a popup list for easy selection of operators, decimals and digits. Hold the pen stationary for a second where you want the new symbol to appear and a popup list of symbols will appear under the pen. Move the pen up and down until the required symbol is highlighted and then release the pen. To access additional symbols, move the pen just beyond the bottom (or top) edge of the list (where the black arrow is) and a further selection of symbols will appear. Release the pen and the highlighted symbol will then appear on the screen at the position where the pen was first held down. Be careful with the positioning of short symbols like '.' and '-'. They need to be centered (vertically) between their neighbours. To achieve this, the initial pen position (to trigger the popup list) should be on the dotted centre guide line that extends to the right of the selected symbol.


Entering Numbers or Digits

Digits are written using the familiar graffiti strokes (see diagram to the right) but onto the main Palm screen instead of the lower graffiti area. Digits are shown as they are being written. Since the digits are recognised by the built in Palm graffiti recogniser, the same basic rules apply as when writing in the graffiti area:

After the pen is lifted, the current number is usually verified at the side of the screen. Check this verification carefully to ensure what has been recognised is what you intended to write. If you have any experience with graffiti, you know that it can sometimes misread your entries, especially if you are not writing strictly according to the graffiti outlines as defined by Palm.

If a digit is not recognised at all, a dialog will be displayed to allow you to nominate the correct digit (see left) This is the 'instant correct' feature new in CalcWrite 4.0. Tap the correct digit or operator to dismiss the dialog. If a digit is wrongly recognised it will verify as an incorrect digit (see example at right where a handdrawn '3' is too small and has been seen as a '2'). If so, erase it (backspace in numeric graffiti area) and enter it again. Or you can enter the correct digit as graffiti, although this will not change the look of the digit already drawn on the screen.

Another way of correcting an error is to draw a long horizontal line from left to right across both graffiti areas. If an incorrect symbol is selected, this will bring up a dialog allowing you to tap the correct value. Audible verification is also available if required. (See preferences)

Be especially careful with digits like (6) (often mistaken for (4) if the end is not curved enough, likewise a badly formed (3 or 4) can become (9) etc). Loopy (2)s can be mistaken for (4) or even (8). A graffiti (2) has a straight bottom. 3's can be mistaken for 8's if the beginning and end are too curled.

To more closely approximate the real handwriting world, CalcWrite optionally allows some digits to be entered with extra strokes. These are the digits 4, 5 and 7. (For example, with 5, you have the option of entering the top line as a second stroke). This facilitiy is provided as a convenience only and may be turned off by setting the "Graffiti only" preference. If entered, the extra stroke is ignored and is not essential to the operation of CalcWrite. The digit 8 can be entered as two circles, one beneath the other, but the second circle must start within the shaded area. If you are comfortable using just the graffiti shorthand strokes, then that is all you need. The screen display may look a little strange, however. If you do enter the extra strokes when writing 4, 5 or 7, they should not cause any problems. Extra strokes can only be entered when the digit is first being drawn. To indicate this, shading is displayed underneath the (incomplete) digit - see picture at left. Once you enter the extra stroke, the shading disappears (see picture at right) and you cannot come back and add extra strokes later unless you use the popup menu's 'Add more strokes' option.

If you are used to drawing a closed '4' (as compared with the open graffiti '4') this can be formed by using two strokes. One stroke is a vertical '1'. The other an open graffiti '4' stroke crossing that vertical stroke The first part of the open '4' stroke can be angled, but not too much or else it won't be recognised as a '4'. The '4' stroke and its matching '1' stroke can be drawn in any order. (See example to left. There is no necessity for the gap at the top, it was just drawn that way to emphasise the use of two strokes). There is currently no way of writing a closed '4' as a single stroke.

Extra strokes must start inside the box that outlines each digit to be considered a part of that digit. Otherwise it may be recognised on its own as a separate digit. Be especially careful when adding a backslash (\) to a slash (/) to form the multiply operator. If the second stroke starts outside the box around the first, an error will occur. The screen shot to the right shows the basic graffiti stroke in the left column and CalcWrite's enhanced graffiti (with an extra stroke) in the right column.

Hint: If you go to enter a second stroke to a 0, 4, 5 or 7 and find the digit moving around with the pen, your digit has probably been misrecognised as one requiring only one stroke (eg a 0, 1, 2, 3, 6 or 9). If a single stroke digit has been recognised, the area underneath it will be clear, not grey. Glancing at the confirmation line on the screen will confirm the incorrect recognition. Erase the incorrect digit and enter it again.

Digits may also be entered by holding the pen stationary on a blank area of the screen until a popup menu appears (see example to the left). Scroll the menu to select a digit which will appear at the initial pen down position. You can freely mix hand drawn and typed digits anywhere on the screen.

If one digit is drawn too close to the previous digit, the second digit may be considered to be just part of the first one and thus ignored.

In colour handhelds, digits will appear in black.


Entering Dots, (also known as Decimal Points or Periods)

Care must be taken when entering dots on the screen because they are small compared with the size of the digits 0 - 9. Small dots (like digits that are written too small) are extremely suitable candidates for misinterpreted by CalcWrite.

If you aim to place the dot approximately centred vertically between the top and bottom of the preceding digit you should have no problems. If you are using the guidelines (recommended) place the dot on the dotted line extending to the right of the selected digit (see diagram to the right). If the dot is too close to the top (or bottom) of the two surrounding digits, it may be 'seen' as part of the number on the line above (or below) causing your calculation to fail. CalcWrite attempts to warn you if this situation occurs.

For example, "4.1" may be recognised as "41" if the dot is too high or too low, meaning your calculation could be out by 37.9. Depending on what number is on the line above (or below) a misplaced dot may affect that number too.

Because dots are small but critical, they are shown enlarged on verification (ie as "") so that any misplaced dots are very obvious.

A dot may be placed at any time between any two digits, but be aware that each digit has a certain area surrounding it to make it easy to tap and select it. So if you attempt to insert a dot in the overlapping 'tap areas' of the two digits, one of the two digits will be selected instead. If this happens, just drag that digit a little further away then re-write the dot.


Guiding Boxes

After lifting the pen at the completion of writing a digit or operator, a box is drawn around it, with a line above and below. Use the box and lines as a guide to where to write the next stroke or symbol. This guiding box shows the borders of the symbol you have just entered to indicate where it is safe to enter the next one. If the next symbol you enter on the same line is slightly taller, the spacing of the top and bottom guidelines will be automatically adjusted to suit.

  1. If adding another stroke, be sure to start it within the shaded guiding box.

  2. If entering another symbol to its right, write sufficiently beyond the (right hand) edge of the guiding box to avoid any overlap.

  3. If starting a new line, make sure the next digit is completely below the bottom line under the guiding box.

  4. If centering a decimal point (.) or minus sign (-), be guided by the line jutting out from the right hand side of the guiding box.

The 'Guiding Box' feature can be turned off in the Preferences menu ('Show writing guidelines" checkbox). However it is there to help you. Without it, you greatly increase the chance of your handwritten digits being incorrectly grouped into numbers.

If you go to a random location on the screen and attempt to write another symbol between symbols already on the screen, no guides can be shown. (Guides are always based on the previous symbol written). In this case, extreme care needs to be taken to allow sufficient space between your new symbol and its neighbours, whether they be to the side or above or below. Likewise if you drag a digit from one screen position to another.

In colour handhelds, guiding boxes wil appear in green.

As a general rule, entering symbols from left to right then from top to bottom is safest, since guiding boxes are then always displayed to help you.


Entering Operators (+, -, x, ÷, % and square root)

Operators comprise plus (+), minus or negate (-), multiply (x), divide (÷), percent (%) and square root as well as two different forms of equals (= and _____ ). These may be entered into CalcWrite in one of three ways: by writing normal mathematical operators on the screen, by selecting from a popup menu, or by writing a graffiti stroke in the appropriate lower graffiti area. In colour handhelds, operators will appear in blue.

1. Writing on the screen

As the graffiti for these symbols bears little resemblance to real world mathematical symbols, additional strokes have been specially defined.

2. Selecting from a Popup Menu

Hold the pen down stationary on the screen where the operator is to be placed until a popup menu appears under the pen (see right). Once the popup menu appears, move the pen up or down until the required operator is highlighted. Release the pen and the highlighted operator will appear where the pen was first tapped. Select 'cancel' if the menu appears by accident.

3. Writing Graffiti Strokes

Using graffiti requires the correct extended shift stroke for plus (+), minus or negate (-), multiply (X) and divide (÷) in the graffiti area as defined by Palm (See diagram to the right). The operator so drawn will appear to the right of the selected symbol on the screen. If there is no selected symbol, it will appear at the top left of the screen. It is not currently possible to enter a leading operators or signs using graffiti without dragging them into their correct position after entry.

 


Selecting and Editing Digits

To select a digit or operator for editing, simply tap near its centre with the pen. A selection box will appear around the symbol you tapped to show that it has been selected.

Note: The selection box is often larger than the digit itself (to allow room to add strokes) and may appear to enclose more than one digit or operator. In CalcWrite, only one digit or operator can ever be selected at any one time.

Note: If you accidentally tap just outside a digit or operator when selecting, it will not be selected, instead a dot will appear selected on the screen where you tapped. Remember that dots are significant to CalcWrite - they represent decimal points. It is important to delete any such erroneously entered decimal point before proceeding, otherwise it may accidentally form part of the next calculation you perform. To delete the extraneous dot, just draw a backspace in the right hand (numeric) graffiti area.

Note: Tapping on a digit or operator that is already part of a completed calculation (ie where a result is showing on the screen) with the recalculate automatically preference turned off, will cause the calculation result to be cleared. This is because the result is no longer correct as you are modifying one of the terms used to produce that result.

If a digit has been incorrectly recognised, it can be corrected in several ways.

If you wish to add additional digits, just write them in any available white space. For example, there is usually space to the left or right of a number. If wishing to add a digit between existing digits, you can make room by sliding the existing digits to the left or right. You may have to select and then slide other digits out of the way first to make space for your new digit.

Digits or operators can be dragged anywhere on the screen that makes sense. You can tap on a digit to select it then start dragging in one single action. The entire calculation can be rearranged in this way. If several drags are needed to complete the rearrangement, you may temporarily end up with an invalid calculation. If so, CalcWrite will report an error, but you can simply keep dragging until it is rearranged the way you want it. The only place it doesn't make sense to drag a digit is right next to a subtotal (or total) line. Likewise, you cannot dragor delete the computed digits of the result as it would no longer represent the correct result.

To insert a digit between two others, you may need to drag them apart first to make room.

If your calculation extends over several screens, dragging a digit or operator across the top or bottom edges of the screen will cause the rest of the calculation to automatically scroll into view.


Precedence and Brackets

CalcWrite's normal precedence is strictly left to right, top to bottom in the order symbols appear on the screen (not the order they were written). With a normal calculator, each time you enter an operator and another number, an intermediate result is calculated, which then feeds into the next calculation. CalcWrite works the same way, although intermediate results aren't shown.

Round brackets may be used to change the order of calculation. In order to use brackets, the "Allow ()%/" preference must be ticked. Insert opening and closing brackets to group sub-calculations you wish to be computed together

CalcWrite automatically inserts a multiply operator (x) after a number that appears preceeding an opening bracket (eg after the '2' in the example to the left). CalcWrite automatically inserts a multiply operator (x) between any pairs of adjacent brackets that appear on the same line. For example, "(3-2)(2+4)" is taken to mean "(3-2) x (2+4)". If the closing bracket of one term and the opening bracket of the next term are on separate lines, a '+' is inserted between the bracketed terms (rather than a 'x') for consistency with CalcWrite's column style of operation.

Within brackets, the precedence is always left-to-right, top-to-bottom.


Clearing selected entries from the Screen

The selected digit is the one contained in the (dotted or shaded) box.

To erase the selected digit write a backspace (horizontal line from right to left) in the numeric graffiti area (the right hand side). If an optional second stroke has just been entered to complete a 4, 5, 7 or 8 this will just delete that second stroke. Otherwise the entire symbol will be deleted. If a result has just been calculated, entering the backspace will clear both the printed result and the line or equals sign that triggered the result.

To erase the entire number containing the selected digit, write a backspace (horizontal line from right to left) starting in the alphabetic graffiti area (the left hand side). This will clear the selected digit, the rest of the number it is contained in and any operator associated with it. In column style, this will usually clear a complete line.

To clear the entire calculator screen, write a backspace (horizontal line from right to left) starting in the numeric graffiti area (the right hand side and continuing on well into the alphabetic graffiti area. Backspacing across both areas clears all numbers and operators, including any that are currently scrolled above or below the screen. This effectively resets the entire calculator.

If after clearing entries or numbers, the screen is completely empty, the message "-- Cleared CalcWrite v8.0 r --" will appear.


Scrolling the Screen

Scrolling in CalcWrite occurs either manually or automatically. If automatic scrolling is selected in the Preferences screen of the registered version, then when the pen is released near the bottom of the screen an automatic scoll up takes place to make room for subsequent numbers. If using this option, you need to wait until the scrolling has completed before adding further strokes or digits on the same line.

Manual scrolling is performed using the two arrow keys located at the bottom centre of your Palm device. The lower of these buttons scrolls the screen contents upwards whilst pressing the upper button scrolls in the opposite direction. The Sony Clie jog wheel can also be used. Any combination of manual and automatic scrolling can be used together.

Tapping on a partially visible digit or operator scrolls it completely into view.

When dragging a number or operator over the bottom (or top) edge of the screen, the screen will automatically scroll up (or down).

CalcWrite's can work with a 'page' that exceeds 200 Palm screens in length (to get to the very bottom would require pressing the scroll button over 2,000 times). This is equivalent to around 37 feet or over 12 metres of calculation !!


Computing Results

To activate the column style calculation you have entered on the screen, simply draw a horizontal line under the column of numbers. The result will appear centred under the line you drew. The horizontal line you draw needs to be at least 1/8th of the screen width in length, to distinguish it from a minus sign.

To calculate the result of an equation style calculation, just write an equals sign (=) after the equation. The result will appear to the right of the equals, if it fits, otherwise on the next line.

If the "Verify calculation" preference is set, the equation used to perform the calculation is displayed underneath the result. For example," [3 x 2 + 6 = 12]". Always check this equation carefully to ensure that CopyWrite is calculating the same equation you believed you entered. If any of your handwritten digits have been misrecognised, you will see the effect in this equation. CalcWrite tries to ensure this equation is visible when you ask for a result by scrolling the screen a bit.

If the "recalculate automatically" preference is set, once a result has been computed, it will be re-computed each time the pen is lifted after a change has been made.

In colour handhelds, results will appear in blue except for negative results which will appear in red.


Using a Result in Further Calculations

Once a result has been calculated and entered on the screen, it can still take part in further calculations. Simply add an operator (+, -, x, or ÷) underneath or to the right of the result and a number after it. (To add additional numbers, just start writing them underneath the previous result). You can overwrite the verification equation if necessary. It will vanish as soon as you start writing over it. Continue to write operators and numbers in the usual way until the calculation terms have all been entered. Then draw a horizontal line or equals sign as usual to trigger calculation. The result calculated will start with the previous result as its first number and use the new operators and numbers you entered to calculate the new result. In this way, the previous total has now become a subtotal.

If the recalculate automaticallypreference is off, as soon as you modify before a subtotal, the subtotal and anything entered after that subtotal will be automatically cleared as it is no longer valid. If recalculate automatically is on, all subtotals remain on the screen and are kept up to date as the terms of the calculation are modified.


Reworking a Previous Calculation

With CalcWrite it is possible to recompute a calculation after changing some of its component numbers. Simply go back and modify the numbers by changing or deleting any of its digits, or adding new ones. See Selecting and Editing digits.

Be careful with positioning the new symbol(s) as the guides for the line you are modifying may not be on the screen. If this is the case, you can always select an existing digit on the new line first (to bring up its guiding box and lines) to guide you in positioning the new or changed digit.

Calculations can be completely rearranged by dragging digits to any new position on the screen. Digits can be selected and dragged in one motion. Digits can be dragged from one end of a number to the other, or from one line to another. Operators can be moved from the beginning to the end of a line, or from one line to another. If the recalculate automatically preference is on, each time you rearrange the digits, any existing subtotals and totals will be recomputed and redisplayed as soon as you release the pen. This feature gives an amazing amount of power in demonstrating mathematical concepts like commutativity and associativity.

If the recalculate automatically preference is off, all totals and subtotals after the point of change will be erased. You will need to draw a new line (or equals) to get an updated result.


Preferences

CalcWrite implements a number of useful preference settings (explained below) to enable the program to be adapted to your exact needs:

 

 

Round to (decimal places): float Confirm digits: Visually Scroll at bottom of screen: On * Show writing guidelines: On Verify calculation: On
Recalculate automatically: On Allow ( ) % /: off Report input errors: In detail User is: Righthanded Single slash means: multiply
Splash screen: On Graffiti only: Off Popups stay down: off Fast popup: off Report conflicting hacks at start: off Handwriting Smoothing: 3

*Scroll at bottom of screen: is on for registered version of CalcWrite, but disabled in the demonstration version.


 

Menus

CalcWrite has a main menu (accessible from the menu icon in the bottom left hand corner of the graffiti area) and two popup menus. One popup menu assists editing of digits or operators already on the screen. The other allows a way of entering operators or digits without having to draw them.

One popup menu is activated by holding the pen stationary over an existing digit or operator and offers editing facilities connected with just that digit or operator (See left).

The second popup men is activated by holding the pen stationary in any blank area of the screen. This popup menu allows the entry of digits or operators without having to draw them by hand. (See left).

 

CalcWrite's main menu offer the following choices, (each with its own graffiti shortcut):

 


Bugs

Yes, there are sure to be some. If you find a bug, please let us know so we can fix it and get a new version to you as soon as possible.

 


HandEra 330 Support

The HandEra 330 is a PalmOS based device with several advanced hardware features, including a larger rotatable screen and virtual graffiti area. CalcWrite 8.0 supports the larger screen real estate of this device and will operate in any of the rotation modes, although the default portrait mode works best.

CalcWrite is an application that makes good use of the larger screen, by allowing more of the calculation to be visible at any one time. Column style calculations are enhanced by the HandEra portrait modes due to their essentially vertical nature, whilst equation style calculations are best suited to the two landscape (horizontal) modes. However, CalcWrite will operate in either column or equation style in any of the four Handera supported rotations. Its entirely up to you.

To rotate the HandEra screen from within CalcWrite, access the Preferences screen from the menu. A 'Rotate' button is available at the bottom of the 'CalcWrite Preferences' screen (see left). Pressing this button allows you to choose one of the four available rotation modes (see right).

On the HandEra 330, the graffiti area at the bottom of the screen can be shrunk (minimised) when not required. Since CalcWrite takes (almost) all its input directly from the main screen area, the graffiti area is rarely required. In fact, on a non-HandEra Palm device, the graffiti area is only used in CalcWrite to input three separate erase strokes. On the HandEra 330, these strokes are instead represented by three small buttons displayed in the shrunken graffiti area. Thus the graffiti area can remain minimised all the time whilst using CalcWrite, leaving most of the screen for writing your calculation. The HandEra has almost twice the vertical screen space of a standard Palm device available for calculation use. If you choose not to minimise the graffiti area on a HandEra 330, it operates exactly as outlined in the preceeding manual for standard Palms, with erasure being performed by the usual three horizontal strokes across the graffiti area.

The three erasure buttons that appear only in the minimised graffiti area are (from left to right) :

  1. Clear Number - clears the selected symbol. If a stroke has just been added, clears that stroke.
  2. Clear Entry - clears entire number (including any operator) containing the selected symbol.
  3. Clear Calculator - clears the entire calculation and resets the calculator.

In these three icons, the 'X' indicates which portion of the calculation will be cleared.

This makes CalcWrite an ideal HandEra 330 application since use of valuable screen real estate is optimised at all times.

The current screen rotation and size of the graffiti area are stored upon exit from CalcWrite and restored when next run.


Known Deficiencies in CalcWrite 8.0

  1. Cannot edit in "View as Text" mode.

  2. Equation style calculations are always displayed column style in "View as Text" mode.

  3. Occasionally all digits get deselected so you may have to tap to re-select one.

  1. CalcWrite has no printing support yet, although you can currently copy the entire calculation (using the menu) then paste it into the memopad application. A textual view of the calculation (column style only) can be saved as a new memo. This memo can be printed from the Palm desktop after the next HotSync.

  2. CalcWrite does not work with third party handwriting recognisers like Jot and TealScript.


Error Messages

The following is a list of the error messages that CalcWrite can produce. Because the layout of numbers is extremely flexible, the possibilities of misinterpretation are increased. Before calculating a result, CalcWrite checks for a number of possible layout (and other) errors and reports them. CalcWrite then terminates the calculation and attempts to highlight the digit or operator causing the problem.

Errors reported by CalcWrite (including the calculation as recognised by CalcWrite) are: (additional explanations, where necessary, follow in italics)

The following errors are internal and if they occur, they should be reported to the author. They usually indicate a program bug or incompatibility with the particular Palm model and PalmOS version you are using.


The Future

It is hoped that in the future, CalcWrite's few current entry and placement restrictions can continue to be relaxed. (There has already been some relaxing of restrictions from version 1 to the present). CalcWrite represents a genuine breakthrough in calculator technology. This is early days, however. It can only get better with your feedback. Future versions of CalcWrite may be able to be 'fine tuned' for even greater placement and number entry flexibility. In particular, if Palm eventually replaces graffiti with less restrictive recogniser technology, CalcWrite will be able to take advantage of it. In the meantime, if readers know of a more flexible commercially available recogniser (with programmer's SDK) for PalmOS, please let us know.

We could like to encourage other developers to produce "Pen powered", rather than just pen-assisted Palm applications. Or perhaps convert existing applications to this way of working. ( "Pen powered" applications work by displaying and manipulating purely handwritten symbols exactly as they were entered. The conversion to ascii text is always hidden from the end user).

By the way, Microsoft are also attempting to legitimise this approach with their newly announced "TabletPC" concept which promises to make 'ink' (handdrawn pen input) a 'first class citizen'.

The education market (particularly in the early years when they are just learning to write) is crying out for computer applications that work naturally with the handwritten input of either numbers or text. The Palm is the ideal platform for this. Please contact us if you need help converting educational applications to use this form of handwritten input. We would be more than happy to provide technical advice and code, if necessary.