PsCalc
A Calculating revolution
for the Psion Series 3

by Nick Buckenham & John Crook

Why another calculator for the Series 3? It's already got one!
The Psion Series 3 is infinitely better than the old Organiser .... except in one respect. It doesn't have a numeric keypad! Any serious number cruncher will soon give up when he/she has to use the top row of the keyboard to enter any volume of numbers.
Hence PsCalc......

As you can see below the  keys under 7, 8 & 9  have been used as a standard numeric keypad.

	4		5		6		%
	U		I		O		P

	1		2		3
	J		K		L

	,		O			.	.
	N		M		,		.

The Hardware Changes.
Just print or type the above numbers on a sticky label, cut them  out and stick them  on the keyboard and you are away!

Loading the Program.
The program is an "application" which should be installed via the system "Apps" menu. (See the Psion manual.)  Ccopy both programs  to the APP directory on the A, B or Internal drive. It can be allocated to one of the "Buttons". It expects an icon file ("\APP\PsCalc.pic") on the same drive as "\APP\PsCalc.opa". Once run a small data file is also created on the APP directory of your "default" drive.

Using the Calculator.
It is quite straight forward. Try entering some sums - using either or both sets of number keys. Hit enter. The answer appears and the original sum moves up. If you start a new sum the previous answer clears ready for the new sum. If, however, an operator (+,-,/ or *) is pressed the previous answer remains. Each time Enter is pressed the answer appears and the previous sums move up through the four registers. Only the sum is kept in the registers - if you want to keep the answers press Enter twice.

A Word about the Display.
PsCalc holds answers to one level of accuracy and displays to another. An accountant may want to use an accuracy of 2 dec. places and display 2 dec. places. An engineer may wish to display 3 dec. places but hold to 6 dec. places. The options can be set via the Menu. (See below). In addition the format can be General or Scientific.

Editing the Current Sum.
The cursor keys will move the cursor along the current sum. The Psion key plus the left or right arrow moves the cursor to the start or end of the line. The Control key and a cursor key moves the cursor 10 places. The delete key deletes the character to the left of the cursor. Shift Delete deletes the character under the cursor.

Editing a Previous Sum.
Use the Up arrow to highlight the required sum. Hit enter and it is copied down to the current register at the cursor position. Alternatively "Psion E" edits (rotates) the registers to allow changes to be made or a sum repeated.


Menu/Hot Keys.
The menu key gives access to all the functions. (You can also use the Psion hot keys.)

Memories
Any two of the usual memories (M0 - M9) can be accessed. The particular  memory numbers you want to use are set via the Settings menu card.
The second memory can be addressed using the menu card or the Psion hot keys. The fist memory can only be addressed by using the Control key instead of the Psion key.
The memory menu card is self explanatory! The Help screen gives a bit more info.

The "Settings" Menu Card.
The first four options should be self explanatory. The Percent VAT allows the rate held to be changed from the default of 17.5%. See below for the VAT key.
The Thousands option is unique. It turns  on a row of 000's markers to help when reading long numbers.

The "Others" Menu Card.
The Edit (Rotate) key has already been mentioned.
The Vat key. Enter a Vat inclusive figure in the input line. Hit Psion V and the net figure appears in the answer. BUT look at the register above. The Gross figure is displayed followed by the Vat amount. For example enter 117.5 and hit Psion V. The answer shows 100.00 and the register shows 117.5-17.5.
Conversely if you follow the figure you enter with a "+" the Vat will be added. ie from net to gross. E.G. enter 100+ and hit Psion V and the answer is 117.50 and the register shows 100.00+17.50.

Back to the "Other" Menu card.
Zap the List clears the registers but leaves the memories intact. Exit unloads the program but leaves the memories and default settings intact.

Some Hints and Tips.
Most functions can be applied to sums as well as answers. If, for example, you want to put the answer of a sum into memory just enter the sum and hit Psion or Control+I and the answer is displayed and put in memory.
To type in letters (e.g. LOG) use the Shift key.
Trig works but only uses Radians. To find the Tan of 45 degrees type TAN(RAD(45)).

Note PsCalc will run on the Series 3a - in Series 3 mode.	

Copyright 
John Crook & Nick Buckenham
 This software is available as Shareware. It may be passed on to others. Please send œ9 if you find it useful. A set of key labels will be sent by return. Cheques payable to John Crook.
Pencoed Software, Sheets Heath, Brookwood
Woking, Surrey, GU24 0EL.
Disclaimer.
Care has been taken to check this software fully. However no responsibility can be accepted for any loss , either direct or indirect, arising from errors in the program or for any other reason.

November 1993.