Wednesday, 22 October 2014

Reverse Polish Notation Calculator update

The Superdecade Games Reverse Polish Notation Calculator has received a new update.  Marvel at the new colour scheme and amazing features!

Find the downloads page here - follow this link.

RPN Calculator has been expanded to include loads of new features (see below).

Here is a quick summary:

* Enter Reverse Polish Calculations in a single line.
* Denary, Binary, Octal and Hex modes.
* Open Windows dialogue boxes.
* Search Google or Bing from the calculator.
* Full BB4W source code provided for the curious student.

For more on Reverse Polish Notation - follow this link.

RPN Calculator Help version

Reverse Polish Notation is a method for expressing algebra in which the operators are placed to the right of their operands. For example, the algebraic expression (4+5)*3 becomes 4 5 + 3 *.
Functions are placed to the right of their argument, and return a single value. For example, sin(x+y) becomes x y + sin
Visit the RPN homepage.



  • +         Addition.
  • -         Subtraction.
  • *         Multiplication.
  • /         Division.
  • ^         Raise to power.
  • div       Integer division.
  • mod       Remainder of division.
  • and       Bitwise logical AND operation.
  • or       Bitwise logical OR operation.
  • eor       Bitwise logical EXCLUSIVE OR operation.
  • ==      Checks for equality between the operands. Returns -1 (true) if the two operands are equal, otherwise returns 0 (false)


  • abs A function which returns the absolute value of its numeric argument.
  • acs A function which returns, in radians, the arc-cosine of its numeric argument. The permitted range of the argument is –1 to +1.
  • asn A function which returns, in radians, the arc sine of its numeric argument. The permitted range of the argument is –1 to +1.
  • atn A function which returns, in radians, the arc tangent of its numeric argument. The permitted range of the argument is from minus infinity to plus infinity.
  • cos A function giving the cosine of its radian argument.
  • deg A function which converts radians to degrees.
  • exp A function returning 'e' to the power of the argument.
  • int A function truncating a real number to the lower integer.
  • inv A function which returns the inverse 1/x of the argument.
  • ln This function gives the logarithm to the base 'e' of its argument. The 'natural' number, 'e', is approximately 2.71828183.
  • log A function giving the base-10 logarithm of its argument.
  • not A function return the opposite boolean value to its argument. All +ve/-ve numbers evaluate as -1 (true). Zero evaluates as 0 (false)
  • rad A function which converts degrees to radians.
  • rnd A function which returns a random number. The type and range of the number returned depends upon the optional parameter.
  • sgn A function returning –1 for negative argument, 0 for zero argument and +1 for positive argument.
  • sin This function returns the sine of an angle. The angle must be expressed in radians, not degrees.
  • sqr A function returning the square root of its argument.
  • tan This function returns the tangent of an angle. The angle must be expressed in radians, not degrees.
  • round This function returns a real number rounded to the nearest integer.


  • copy Copies the accumulator to the Windows Clipboard. NB CTRL+C copies the current input line to the clipboard instead.
  • help Loads this help file.
  • clear Sets the accumulator, all user-defined variables and the system clock to zero.
  • quit Closes the RPN calculator without further warning.
  • den Enters DENARY mode (base 10).
  • hex Enters HEXADECIMAL mode (base 16).
  • oct Enters OCTAL mode (base 8).
  • bin Enters BINARY mode (base 2).
  • acc on Prevents the accumulator from clearing between calculations. The value of each calculation is added to the previous value of the accumulator.
  • acc off Returns the accumulator to its usual behaviour.
  • set time Opens the Windows 'set time' dialogue.
  • set date Opens the Windows 'set date' dialogue.
  • programs Opens the Windows 'programs' dialogue.
  • admin Opens Windows admin tools.
  • sound Opens Windows sound controls.
  • version Shows current version of RPN calc and OS.
  • files Opens windows explorer.
  • power Shows current power status.
  • cp Opens Windows 'control panel' dialogue.
  • google Sends search query to Google, eg google this thing.
  • bing Sends search query to Bing, eg bing this thing.
  • define word Defines the search term using Google.
  • free space Shows free space on drive letter, eg free space c.
  • magnifier Opens Windows magnifier tool.
  • notepad Opens Windows Wordpad.
  • ping Sends a ping to ip eg ping
  • tasks Opens Windows task scheduler.
  • cmd Windows command line.

Special variables and constants

  • pi This variable has a constant value of 3.14159265
  • time This special variable holds the value of the current internal system clock in centi-seconds (one-hundreths of a second).
  • last This special variable holds the current value of the accumulator. Thus a calculation can make use of the previous result.

Making an assignment to a variable

The RPN calculator has 26 variables with the identifiers 'a', 'b', 'c' ... 'z'. Assignment to a variable is made as follows:
5 5 + = x
Here, the value '10' is assigned to the varible 'x'. This variable can now be used in further expressions.
All variables are initialised to zero upon the program starting, and can be cleared with the clear command.

User Interace


  • Insert - Toggle Insert/Overwrite mode
  • Enter - End input
  • Esc - Terminate input, returns NUL string
  • Ctrl+J - As Enter but does not store in line history
  • Ctrl+S - Toggle case of current character
  • Ctrl+T - Transpose adjacent characters
  • Ctrl+G - Sound system bell


  • Left - Move left one character
  • Right - Move right one character
  • Ctrl+Left - Move left one word
  • Ctrl+Right - Move right one word
  • Home - Move to start
  • End - Move to end


  • Ctrl+C - Copy line to clipboard
  • Ctrl+X - Cut line to clipboard
  • Ctrl+V - Paste text from clipboard


  • BkSp - Delete left one character
  • Del - Delete right one character
  • Ctrl+U - Clear input buffer
  • Ctrl+Home - Delete to start
  • Ctrl+End - Delete to end


  • Up - Previous input
  • Down - Next input
  • Ctrl+Up - Select first input in buffer
  • Ctrl+Down - Select last input
  • Shift+Up - Skip back 16 inputs
  • Shift+Down - Skip forward 16 inputs

Error messages

Stack is empty

This error is generated when the calculator cannot find an argument to a function, or the operands to an operation. This error is generated by the following example: 4 +.

Insufficient operators

This error is generated when the calculator cannot find the right amount of operators for the expression to make sense. The following example will generate this message: 4 4

Unknown operator

This error is generated when the input makes no sense to the calculator. This is usually generated by spelling mistakes.

Friday, 17 October 2014

A simple Clock App in BBC BASIC

     rem Simple Clock
mode 12:off
date$ = left$( time$, 15)
       clock$ = right$( time$, 8)
       *font Courier New, 60
       print tab(2, 3)date$
       *font Courier New, 94
       print tab(2,3)clock$
       wait 50
     until false

This code produces a very simple, but rather effect clock app.

Monday, 22 September 2014

Another bug fixed in Spellunker

Spellunker should now run happily for all users.

Bug fixed - system crashed if admin rights for Windows sound was disabled.  Some PC's in schools are set up so sound can only play through the headphones - so as not to annoy tired teachers.  Spellunker will now 'fail silently' in these circumstances.  If you are having no problems with version then there is probably no need to upgrade at this point.

Happy Spellunking!
Proceed to the downloads page.

Proceed to the downloads page.

Saturday, 20 September 2014

Bug fixed in Spellunker

I became aware of a bug in Spellunker that crashed the game shortly upon loading.  This bug is now fixed and you can download the latest version of Wordsworth's adventures on the downloads page by following this link.

I have now test the game on my Windows 7 and 8.1 machines and everything is working as expected.  I have also run the game from a USB device without any problems.  If anyone still has difficulties getting version working, please let me know through the contact forms on this page.

Join Worthsworth Spellunker on his adventures in the Qwerty Caverns.

Cast 'spells' using the letters provide to defeat the various obstacles in Wordsworth's way.

Defeat the Semanticore and the dreaded killer spelling bees.

Score points for the longest possible word within the time limit.
Follow this link to the Downloads page.

Sunday, 14 September 2014

Spellunker - the adventures of Wordsworth Spellunker

Introducing our latest game - Spellunker (the adventures of Wordsworth Spellunker)!

Spellunker is a spelling game for Windows.  Defeat each level by earning as many points as you can spelling words from the letters you are given.  Help our hero, Wordsworth Spellunker find his missing parents by defeating the Semanticore!  Ride the Lexicorn and out spellunk the cyclops.

Just beware of the Killer Spelling Bees!

Spellunker is a spelling game with a story (thanks to Ben for writing the story, and Pob for the artwork).

Play with your mouse or touch screen.  Over twenty levels of spelling fun awaits you...

Proceed to the downloads page.

Three minutes - Sixteen letters.  Spell as many words as you can to defeat each level.  The longer the word, the more points you score.

Help our Hero Wordworth Spellunker find his parents by defeating the various perils of the Qwerty Caverns.

Thursday, 4 September 2014

File Analyser

File analyser

There is a common misconception in computing that computer files have inherent qualities about them that define them.  For example, image files actually ARE pictures, and that .wav and .mp3 files actually ARE sounds, when in reality they are a series of binary values stored on disk. I have also seen students attempting to convert bitmap files into jpeg format by removing the .bmp extension and replacing it with .jpg (completely ignoring any compression codecs and metadata required)!

The reality is that all files a series of binary 'bytes' that are interpreted by your operating system or associated codecs as needed.  There is nothing inherently 'image-y' about the bytes of an image file - in fact you can load it into any other package - it just wont make much sense to your computer.

The Superdecade Games file analyser program is designed to show how files can be interpreted in different ways, in other words to show the binary nature of all files.

When you load the program you will have 12 options to choose from:  View your file as Binary, ASCII, Hex or denary values; view your file interpreted as colour information; view your file interpreted as sound information, or get a character distribution - ie which ASCII values are most common in your file.

The program is at an early stage of development, however your interest may prompt further development.

Proceed to the Downloads page...
Choose from one of 12 output modes.

View your file as binary data.

View your file as HEX, ASCII or denary.

Convert an image file into 'music' played on one of three musical scales.

Interpret your image as coloured 'pixels'.

Get character distribution data for your graphics package.  Here we are looking at the most common characters in a MS-WORD file (the most common character is an 'e' - by the way).

Thursday, 21 August 2014

Sanctuary RPG

We are loving this game at the moment. Don't be put off by the ASCII graphics, this game has a great deal going for it. Sanctuary RPG has a lot of people working on it, and a lot of development time has been expended (>10000 hours).  Want to fight blue slime?  Want to run a fantasy-themed tavern?  Want to craft your own magical items?  Need to cause a player "STR overflow error" in enemy robots?  Sanctuary RPG is a 'rouge-like' game for you.  Unlike many RPG games a lot of the most cumbersome and boring mechanics have been abstracted away in favour of a face-paced monster-slaughter fest.  The combat system is strategic and fast.  Unlike many games of this genre you do not end up carrying loads of unused items back to the town to sell.  Instead, unused items are salvage for scrap metal that can be used to make even better items.  This makes for a very fast paced game without losing any of the fun.
Hundreds of monsters and objects all crafted in glorious mono-coloured ASCII graphics!

6 customizable characters to choose from.
He reaches into his bag of gold and pulls out some gold!
Combat is fast paced, full of deadly combos and opportunities for cunning strategies.

Find the Sanctuary RPG homepage - you can pay what you wish to help support development - follow this link.

Sunday, 6 April 2014


Circles is a program to aid independent learning in mathematics.

Circles was written for Mr Bakr Al Bazi, Mathematics teacher at the Grammar School at Leeds, who writes:

"3 circles, 6 values for each circle. Students started to investigate these values with no input from me."

"Independent Learning was taking place. Ratio, radius, diameter.... every notion that involved circles was discussed and then pi came in." 

"It was wonderful! I realised that adopting the use of new technology to support traditional instructions has not only it made me change the way I teach, but also the way students learn." 

Saturday, 15 March 2014


We came across this site recently following a recommendation.  Textcraft provides a way of generating Minecraft style text.  You can then save your image as a file to use in your games and websites.

Follow this link to textcraft.

Sunday, 16 February 2014

My Planet - progress report #10

Oh dear!  Here are some screenshots showing the dreadful collapse of my planet.

Friday, 14 February 2014

My Planet - progress report #9

I know you have been dying to find out about my planet's progress.  Sorry for the delay, I hope this information is not mission-critical for you.

Current population:
18.9 million currently alive.
9.2 million currently listening to Pearl Jam in The Underworld.
1.6 with me in Paradise.

Population of the Moon.
zero (why did they all die?)

Play yourself - My Planet is available from ApeApps - (follow this link for Android version and this link for the Windows 8 version. I'm playing on Windows 8.)

Stuff we would like to see in My Planet: more planets; asteroids!; terraform equipment; more planet-development graphics.
Just a graveyard to the 100 brave astronauts and the 33 babies they sired whilst exploring this airless world.  Now they are in the Underworld listening to Grunge music from the 1990s.

Thursday, 13 February 2014

My Planet - progress report #8

Oh dear.  To teach my people a lesson I sent an Earthquake their way.  Now they have lost their 'faith'.  And I only have 20 astronauts left on the moon.

Wednesday, 12 February 2014

My Planet - progress report #7

Houston. We have problem.

My moon in crisis.  Where has the little colony ship gone?

After successfully colonising the moon of my planet with 100 people and full supplies, our intrepid astronauts got to work exploring their new would and, erm, reproducing at a startling rate.  There were 133 astronauts and astro-babies when I went to work, but only 89 when I arrived home.

Tuesday, 11 February 2014

My Planet - progress report #6

59% of people born on my planet are currently alive.
36% of souls go to "Paradise".  

63% of people born on my planet are currently alive.
45% of souls go to "Paradise". 

Today I have exceeded my target of 1000 000 population.  You should notice that the space project is well under way.  That's a satellite in orbit around my planet.

See the tiny blip at top of the moon?  That is a colony of intrepid space adventurers.

Monday, 10 February 2014

My Planet - progress report #5

What have I done, or not done, to make my people stop believing in me?  Or is it that my people have embraced a new humanistic lifestyle with their recent technological gains?  (Look, they've invented piers the size of Italy)
61% of people born on my planet are currently alive.
51% of souls go to "Paradise".

59% of people born on my planet are currently alive.
36% of souls go to "Paradise". 

Tune in soon for colonisation of the moon (or maybe an Earthquake, if my people stop believing in me).  I am sure you cannot wait!

My moon.  Current hypothesis suggests it is made from cheese. but further investigation is required.  If my people can build boats the size of France, they can build a ladder into space.  They just gotta believe.... 
My Planet is a god-game from Ape Apps (follow this link for Android version and this link for the Windows 8 version.  I am playing on my Samsung Win 8.1 tablet computer).

Sunday, 9 February 2014

My Planet - progress report #4

The situation when I woke up this morning.  I've just turned the sun 'on' and found that my population has doubled since yesterday.  I'm one third of the way to my target of one million souls.

 56% of people born on my planet are currently alive.
 53% of souls go to "Paradise".

61% of people born on my planet are currently alive.
51% of souls go to "Paradise".

Saturday, 8 February 2014

My Planet - progress report #3

Breeding like rabbits.  My population is currently 150977.

Here you can see that I've collected enough 'God Power' to pull-off a special move.  I have no interest in rocking my world with an Earthquake just yet, but I am interested in the Colonize Moon option.  Tune in soon to see my brave astronauts making 'One Giant Leap'.
Stats fans:

53% of people born on my planet are currently alive.
59% of souls go to "Paradise".

 56% of people born on my planet are currently alive.
 53% of souls go to "Paradise".

If you are able to contain your excitement, come back tomorrow for more My Planet.

Friday, 7 February 2014

My Planet - progress report #2

It's time for a good deity to turn the rain back on.
Hi all.  I am sure you are all dying to know how my planet is faring.  Well, so far so good.  My planet was completely dry when I finished work today, but I managed to summon a rain cloud the size of Mars to soak the planet from it's northern pole.  The severe drought (literally no hydrogen atoms had formed any bonds with oxygen atoms on the surface of my planet) did not seem to affect the birth-rate: I've nearly doubled the population over-night. 

Statistics fans will want to know: 
53% of people born on my planet are currently alive.
59% of souls go to "Paradise"

Ignore the poor reviews on the App store, and give My Planet a good try from Ape Apps.

Tune in tomorrow for more updates from one deity to another.


Thursday, 6 February 2014

My Planet - progress report #1

I must be doing something right.  A good balance of sun and rain and I've jumped up to 48000 population.  It is still early days my planet - of all the people who have ever lived - over half of them are alive today (compared with Earth - on which 6.5% of all the people who have ever been born are still alive - source 2011).

Most of the deaths on my planet are from the great flood of a week ago.  59% of people on my planet go to "Paradise".  There is no middle ground.  I won't talk about those who went to "The Underworld".

Wednesday, 5 February 2014

My Planet

My Planet is a god-game from Ape Apps (follow this link for Android version and this link for the Windows 8 version.  I will be playing on my Samsung Win 8.1 tablet computer).

The aim of the game is to try and reach a population of one-million.  The game runs in real-time, so you have to check in two or three times a day to make sure your planet has the right conditions for life.

There are two controls:  Sunlight ON/OFF, and Rain ON/OFF.  You need about 12 hours of sunlight per day, and 12 of darkness, otherwise your planet's vegetation either scorch or wither.  You also need the right balance of water - too little and the plants die; too much and your people drown!

I've had the game running on my tablet for a couple of weeks and I thought I would share my quest to reach one-million population.

My planet just after 'The creation.'
After a flood of biblical proportions, my population has recovered nicely and I have a good balance of light and water.  My civilisation should prosper.
This god is saving up for a good Earthquake.

Ooops!  It is too easy for a god to leave the rain on.   Here's hoping my population have learned how to build boats, because there isn't a button for that.