Commands and Tutorial

Author........Zeda Elnara
e-mail........xedaelnara@gmail.com
Project.......Grammer
Version.......2.50.0.2
Last Update...01 March 2012
Language......English
Programming...Assembly
Size..........1-Page app

To follow the progress of Grammer, check out Omnimaga, Cemetech or GitHub, where development is most active.

If you have questions or suggestions, feel free to email me or post in the forums!

Intro

Grammer is a powerful programming language for the TI-83+/84+/SE calculators. Unlike TI-BASIC, it is not designed to do math and as such, Grammer math is fairly limited in some respects. This also means, however, that it uses a math system with its own tricks and optimizations. If you are going to learn how to effectively use Grammer, you will first need the Grammer interpreter on your calculator (this document assumes you have the latest version of the Grammer App). After that, you should become familiar with Grammer's:

Getting Started

First, send Grammer 2 to your calculator. If you have this document, I assume you have the App. Next, run the app on your calc. Grammer is now installed until your next RAM clear.
Grammer Main Menu-- (Default) Grammer programs only Grammer Main Menu-- All Programs and Appvars Grammer Main Menu-- Appvars Only

Grammer Main Menu-- Assembly Programs Only Grammer Main Menu-- Token Hook Enabled

Your First Program

If you want to make a program, you have to remember two very important things:

Now, before I explain all the technical stuff, could you to create this program and run it?

:.0:Return
:ClrDraw
:Text(0,0,"YUM
:DispGraph
:Stop

It should look like this:

alt text

Number System

The Grammer number system works like this: Numbers are integers 0 to 65535. This means no fractions, or decimals. There are a few commands that handle higher numbers.

Let's look at this closer. First, why 65535? That is easy to answer. Grammer uses 16-bit math. In binary, the numbers are 0000000000000000b to 1111111111111111b. Convert that to decimal (our number system) and you get 0 to 65535. If you don't understand binary or hexadecimal, see the Binary Lesson section. Understanding binary and hex is not necessary, but it will help you understand why certain commands act the way they do. Plus, it can help you figure out some advanced tricks.

Now, let's look at some scenarios. If you overflow and add 1 to 65535, it loops back to 0. Similarly, if you subtract 1 from 0, you loop back to 65535. Then you can see that 65530+11=5. You also now know that -1=65535. So what happens if you multiply 11*65535? Believe it or not, you will get -11 which is 65536- 11=65525.(If you ever want to go into more advanced math in college, hold on to this info for when you get into Abstract Algebra. You are working with the ring Z216).

Division, unfortunately is not as nice as multiplication, addition, or subtraction. 3/-1 will give you 0 because it is 3/65535. Don't worry, though, there are ways to get around this, just read the next section.

Math

Grammer math is very different from the math that you are used to. The main points are:

For the first point, let's look at an example of the math string 3+9/58-3*14+2*2:

3+9/58-3*14+2*2
3+9/58-3*14+4
3+9/58-3*18
3+9/58-54
3+9/4
3+2
5

Parentheses are not part of Grammer math, but to give you better control, you have two main options: Use a space or use a colon between chunks of math to compute each chunk in order. In most situations, you should use a colon. So say you want to do ((3+4)*(6+3))/6. You have 3 chunks that you can compute in order:

3+4:*6+3:/6
7:*6+3:/6
7*6+3:/6
7*9:/6
63:/6
63/6
10

Pretty cool, right? That is actually even more optimized than using parentheses! Now, if you are like me, you might not like the look of that missing remainder of 3 in that division. 63/6 is 10.5, not 10, but you know Grammer rounds down. But guess what? There is a system variable called θ' that will contain the remainder after division and other such extra information after math.

You probably want to know what math operations you have access to and what they do, so here you go:

Pointers and More

To understand pointers, you have to understand how memory works. First, every byte of memory has what is called an address. An address, is a pointer to that byte. For example, the first byte of memory is at address 0, the second byte is at address 1, et cetera. On the calcs, there are 65536 bytes of memory addressed at a time. The last 32768 bytes are RAM. This is where your program and everything in it is stored. This has some powerful implications. If you have a pointer to a section of code and you tell Grammer to start executing there, it can jump there immediately. If you have a pointer to a string, you can use that pointer to draw the string or use it. This means you don't have to create any external variables for your strings or sprites. If you want to create an appvar for save data, having the pointer to that lets you edit the data, save to it, or read from it. Pointers are powerful. As such, you will probably be using a bunch of them, so you should use pointer vars:

Pointer Vars-(or just "vars") are two byte values. These can hold a 16-bit number, so these are well suited to holding pointers. These are all the letters A to Z and θ and A' to Z' and θ'. For readability, you can use the lowercase letters instead of A', for example.

How do you store to these? Like all BASIC programmers know, use →. For example: 3→A
Likewise, for a string: "Hello World→A
Don't be fooled, that does not store the string anywhere. It just stores where the string is located in A. So if you change the byte at A, you will change the "H" in your program. If you want to try it, run this program and then check the source again.

:.0:
:"HELLO WORLD→A
:int(A,47
:Stop

You will see that after running the program, it now says "QuartReg ELLO WORLD" ! That is because we changed the first byte of the string to the value 47, which corresponds to the token QuartReg. Be careful! Not all tokens are one byte-- lowercase letters are a notorious example of two-byte tokens.

Where else are pointers useful? The best example is with labels or finding programs. Anything that requires searching, actually. For example, in Grammer, to goto a label, you would do something like Goto Lbl "HI and that would jump to the label named .HI. You can also get a pointer to this label. If you need to jump to that label often, this saves lots of time by not having to search for the label every time. Remember, everything is math in Grammer:

:.0:
:Lbl "HI→A
:Repeat getKey(15   ;`getKey(15` returns 1 if clear is being pressed
:prgmA              ;This calls the subroutine pointed to by A
:End
:Stop
:.HI
:B+1→B
:Text('0,0,B        ;Displays the number B at (0,0)
:DispGraph
:End                ;End the subroutine

Remember to always End your subroutines! Now I want to take time to finally start explaining some code. Labels can be a bit more descriptive than in BASIC. You can use up to 42 bytes for a name, technically, but try to maintain readability. You can also use pretty much whatever tokens you want in a label name. For example, I had a label named ICircle( that I had draw inverted filled circles. Lbl takes a string argument where the string is the name of a label. It returns the pointer to the line after the label.

Goto and prgm let you redirect your program. Goto jumps to the code and prgm will execute the code and return once it gets to End. Both of these take a pointer to figure out where to go.

Repeat works like it does in TI-BASIC. It first executes the code between Repeat...End and then it tests the condition. If the result is 0, it repeats the procedure. If it is anything else, it stops looping and continues after the End.

getKey gives you two ways to read keys. Key codes are different in Grammer from TI-BASIC. The first way is to use it like you would in TI-BASIC. For example, getKey→A stores the current keypress in A. You can also use something like getKey(15 to quickly test a specific key. This is great if you want to use multiple key presses. I shamelessly stole this wonderful idea from Axe, I think. Or maybe somebody suggested it to me? I can't remember.

Drawing

Drawing in Grammer has a few similarities to TI-BASIC, but not many. The first concept I want to tell you about is that of drawing buffers. These include the graph screen and other chunks of memory that you use like the graph screen. A drawing buffer is 768 bytes and there are two that do not use user RAM that you can use in Grammer. Their pointers are π9872 and π9340. The first is called AppBackUpScreen by assembly programmers and the second is what we know as the graph screen. The graph screen is default. You can also use π86EC, but Grammer uses that for scratch work for a few commands as well. Now, to the actual drawing! In all cases, (0,0) is the upper left corner of the screen. If you want to try to draw a circle, be prepared for how awesome this will be to if you were a BASIC coder:

:.0:
:ClrDraw
:Repeat getKey(15
:randInt(0,96→X
:randInt(0,64→Y
:randInt(0,64→R
:Circle(Y,X,R,3       ;Draws a circle with an inverted outline at (Y,X)
:DispGraph
:End
:Stop

If you tried it, you will see that drawing in Grammer is very fast compared to BASIC. One of the reasons is that Grammer does not update the LCD with the contents of the graph screen automatically. This means you have to do it yourself with DispGraph and this means that you can do a lot of drawing without showing your users the behind the scenes stuff.

Now let's say you want to draw to another buffer as default. This is where you use Disp: Disp π9872. Now, whenever you draw or update the LCD, that is the buffer that will be used. This means you can preserve the graph screen. Alternatively, most drawing commands have an optional argument to draw to a specific buffer.

Grayscale

Grayscale is a nice little feature in Grammer that can be used if you do it correctly. Now that you know how buffers work, you can give this a try. First, you need two buffers-- the back buffer and the front buffer. Define these using Disp and Disp ', respectively (both found in the Angle menu). For example, to add the gray buffer, use Disp π9872 and now whenever you use DispGraph, it will update one cycle of gray. Because the LCD does not support grayscale naturally, you will need to update the LCD often and regularly.

A pixel is seen as gray if it is ON in one of the buffers, but OFF in the other buffer. If a pixel is on in the front buffer, it will appear darker. Because grayscale is so important, I will give an example program that draws in grayscale:

:.0:
:π9872→Z
:Disp o Z
:ClrDraw
:ClrDrawZ
:0→X→Y
:Repeat getKey(15)
:Pxl-Change(Y,X       ;Just drawing the cursor
:Pxl-Change(Y,X,Z     ;Pixel changing it on both buffers
:DispGraph
:Pxl-Change(Y,X
:Pxl-Change(Y,X,Z
:If getKey(54
:Pxl-On(Y,X,Z
:If getKey(9
:Pxl-On(Y,X
:If getKey(54:+getKey(56  ;If [2nd] or [Del]
:Pxl-Off(Y,X
:If getKey(9:+getkey(56   ;If [Enter] or [Del]
:Pxl-Off(Y,X,Z
:X+getKey(3
:-getKey(2
:If <96
:→X
:Y+getKey(1
:-getKey(4:If <64
:→Y
:End
:Stop

Sprites

Using sprites is a pretty advanced technique, so don't expect to understand everything here. Sprites are pretty much mini pictures. They are a quick way to get detailed objects that move around making them a powerful graphics tool. In Grammer, the main sprite commands are Pt-On( and Pt-Off( and both have differences and advantages over the other.

Sprite Data

Sprite data is in the form of bytes or hexadecimal and you will want to understand binary to hex conversions for this. For example, to draw an 8x8 circle, all the pixels on should be a 1 in binary and each row needs to be converted to hex:

0 0 1 1 1 1 0 0 =3C
0 1 0 0 0 0 1 0 =42
1 0 0 0 0 0 0 1 =81
1 0 0 0 0 0 0 1 =81
1 0 0 0 0 0 0 1 =81
1 0 0 0 0 0 0 1 =81
0 1 0 0 0 0 1 0 =42
0 0 1 1 1 1 0 0 =3C

So the data would be 3C4281818181423C in hexadecimal.

Sprite Logic

There are 5 forms of sprite logic offered by Grammer, currrently. These tell how the sprite should be drawn and can all be useful in different situations.

Pt-On(

This is used to display sprites as tiles. This means it displays the sprite very quickly, but you can only draw to every 8 pixels.

Pt-Off(

This is a slightly slower sprite routine, but it allows you to draw the sprite to pixel coordinates.

Command List

Here are a bunch of commands that do not fit in the drawing or math category. This is a whole lot of info (about 9 pages), but I made some examples later on so that you can figure out how to use these better :)

Operators

→

This stores the last computed value to a variable. For example Return→A' will store the value output from Return to A'.

Likewise, you can store to some OS variables such as real vars (A through θ) and Strings (Str1 to Str256). For real vars, use the prefix i (the imaginary number) and Strings just use their string number. For example, 3→iA will store to the OS realvar A. "Hello→Str2 will store the string "Hello" to Str2. With Strings, if you use the Str1 token followed by a number like 55, you will be accessing the hacked string 155. Str0 is the same as string 10, remember, so Str00 is the same as Str100.

As another note, when storing to an OS string, if you want to use it as a Grammer string, you need to have ' follow the string name (it adds a newline token to the end of the string).

To store 32-bit results, you will need 2 vars. →AB will store Ɵ' in A and Ans in B. So to store a 32-bit result from multiplication: A*D→AB.

//

This is used to start a comment. The comment goes to the end of the line. A commented line is skipped. As a note, the user can include a comment after code.

"

This starts a string. The output is a pointer to the string that can be used later to reference it.

π

If you put a π symbol before a number, the number is read as hexadecimal. For example, π3F would be read as 63.

!

This has several uses. The first is to work like the not() token in TI-BASIC. So for example, 3=4 would return 0 because it is not true. However, !3=4 would return 1. Likewise, !3=3 would return 0. The other use is with loops and If. For example, If A=3 will test if A is 3 and if it is, it executes the code. However, !If A=3 will execute the code if A is not 3. See If , If-Then, If-Then-Else, While, Repeat, and Pause If.

i

This is the imaginary i. Use this to access OS real vars. For example, to read OS var A and store it to Grammer var A: iA→A. To store a Grammer var to an OS var: B'→iA. This does not read decimals or imaginary parts of a number.

E

This indicates the start of a binary string. This is the exponential E.

Loops/Conditionals

If

If the expression following is not 0, the line following it will be executed. The line is skipped if it is 0. Conditions are computed to the next newline. For example, you can have → and : in an If statement in Grammer.

:If A=B      ;Since A=B is false, the following line is skipped
:9→A

Or also:

:If 3=B→A:*14:-14   ;This is the full statement
:Text(0,0,"Yay!

If-Then

This is similar to If except if the statement results in 0, any code between and including Then and End will be skipped. This works like the TI-BASIC command. For example:

:If 3=4
:Then
:3→A
:9→B
:16→C
:End

If-Then-Else

This is similar to If-Then, except if the condition is non-zero, only the code between Then and Else is executed, otherwise the code between Else and End is executed.

:If 3=4
:Then
:3→A
:9→B
:Else
:16→C   ;This is the code that gets executed
:End

For(

The arguments for this are For(Var,Start,End.

Alternatively, you can use For(Val. Val is the number of times to execute the loop. 0=65536

What this does is load the initial Start value into Var. It executes code until it reaches an End statement, then it increments the var. If incrementing goes higher than the End value, the loop finishes and code continues, otherwise it executes the loop again. So for an example:

:For(R,0,48
:Circle(32,48,R,1
:DispGraph
:End
:Stop

Pause If

This will pause so long as the condition is true for example, to pause until a key is pressed, Pause If !getKey Alternatively, using !Pause If will pause while the condition is false. So to pause until enter is pressed, do !Pause If 9=getKey.

While

While loops are like If, except they keep running the code so long as the condition is True. An If statement is content with just checking if the result is true (true is anything but 0), but a while loop will not only execute the code up to End if it is true, but it will loop back to try it again! To give you an idea, this will keep looping until Clear is pressed, and while it is at it, it will increment A and decrement B:

:0→A→B
:While getKey≠15
:A+1→A
:B-1→B
:End     ;This tells the While loop to End / restart!

Alternatively, !While will only execute the code if the statement is not true.

Repeat

This is a loop that is kind of the opposite of a While loop. This will repeat the code up to an End until the statement is true. So for example, to wait until clear is pressed:

:Repeat getKey=15
:End

!Repeat checks if the statement is false in order to end. For example, to remain in the loop while Enter is being pressed:

:!Repeat getkey=9
:End

Control

Return

This returns a pointer to the next line of code.

Goto

This is unlike the BASIC Goto command. This jumps to a pointer as opposed to a label. For example:

:Return→L
:<<code>>
:Goto L     ;This jumps to the line after "Return→L"

Lbl

This returns the pointer of a label. The argument is a pointer to the label name. For example, Lbl "HI will search for .HI in the program code. Also, you can specify which variable the label is in. For example, if you wanted to jump to a label in another program, you can add a second argument as the name of the var. For example, to find the label HI in prgmBYE: Lbl "HI","BYE

Pause

This will pause for approximately x/100 seconds. So Pause 66 will pause for about .66 seconds.

prgm

This is used to execute a sub routine.

Func

The arguments are FuncPointer[,Counter.

This will automatically execute the subroutine pointed to by <> based on Counter. Counter is based on an internal counter, not based on actual timings like seconds or milliseconds. The default is 128. So for example:

:FuncLbl "DISP
:Repeat getKey(15
:<<do stuff>>
:End
:Stop
:.DISP
:DispGraph
:End

That will do DispGraph several times per second automatically.

Asm(

This can be used to run an assembly program.

AsmPrgm

This allows you to input asm code in hex. (C9 is needed)

ln(

This will let you jump forwards or backwards a given number of lines. For example:

:ln(3
:"NOT
:"Executed
:"YAY :D

Or to jump backwards:

:"YAY :D
:"Erm...
:"Yeah...:ln(-3

L

The list L. Arguments are Lline#,[start,[size,[EOL This let's you execute a specific line number. By default, it starts the line count within the main program, but you can pass an optional start value, an optional size value (default is 32768 bytes long), and an optional End-Of-Line argument (default is 63, the newline token).

Input/Computing

getKey

This returns a value from 0 to 56 that is the current key press. You can use this chart for values.

Alternatively, getKey( will allow you to see if a key is being pressed. For example, getKey(9 will return 1 if enter is pressed

Input

This allows you to input a string. The pointer to the string is returned. (this is not a permanent location, the data will be overwritten the next time Input is used). To get a value input from the user, you can use expr( : expr(Input →A. This will store the result to A

Input can also take an optional string input. The input string will be displayed after what the user is typing. If you execute this code, I think it'll explain it better. It's honestly pretty cool for a calulator.

.0:Return
ClrDraw
Text(°"(x,y)=(           ;ClrDraw sets the cursor to (0,0), so I can use °
expr(Input ",)→X         ;I get the next input here. The string is ,)
Text(,+1                 ;This increments the X coordinate.
expr(Input ")→Y          ;This gets the Y value.
Pxl-On(Y,X               ;Or whatever you want to do with the coordinates.
DispGraph
Stop

Menu(

This requires the default package, GramPkg to be on your calc (in RAM or archived).

Syntax is, Menu(y,x,w,"Header","Item0","Item1","Item2","Exit

It basically makes a pop-up style menu, returning the number of the selected item.

Ans

This will return the value of the previous line

expr(

This will compute a string as a line of code (useful with Input)

inString(

This is similar to the TI-BASIC command. This will return the location of a sub-string. The inputs are where to start searching and the string to search for: inString(SearchStart,SearchString

So an example would be:

:Lbl "DATA→A
:inString(A,"How→B
:.DATA
:HELLOHowdyWoRlD!

The size of the input string is returned in Ɵ' and if there was no match found, 0 is returned.

length(

This will return the size of a variable (in RAM or Archive) as well as the pointer to the data in Ɵ'. For example, to get the size of the appvar named Data: length("UData→A

If the var is not found, -1 is returned.

length('

This is used to search for a line. For example, if you want to find a specific line number in a program, this is what you would use. The syntax: length('StartSearch,Size,LineNumber,[LineByte

The output is the location of the string and Ɵ' has the size of the string. If the line is not found, the last line is returned instead.

solve(

This is a command subset.

CopyVar

This will copy the program named by VarName1 from RAM or archive to a new program named by VarName2. If Varname2 already exists, it will be overwritten. So for example, to copy Str6 to Str7: solve(0,"DStr6","DStr7

This returns the pointer to the new var and the size of the var is in Ɵ' The last arguments are optional. Size lets you choose how many bytes are copied (instead of just copying the whole var). You can also add an offset argument to tell where to start reading from.

CopyDataI

This copies data from loc i to loc f . (Forward direction)

CopyDataD

This copies data from loc i to loc f . (Backward direction)

ErrorHandle

This will allow your program to have a custom error handler. Pointer is 0 by default (meaning Grammer will handle it). Otherwise, set it to another value and Grammer will redirect the program to that location. The error code is returned in Ans. For Example:

:solve(3,Lbl "ERR
:<<code>>
:.ERR
:If =1        ;Means there was a memory error
:Stop
:End

Ans and Ɵ' are put back to normal when the error handler completes.

Errors:

CallError

This will execute the error code of a Grammer error. For example, to make a Memory error: solve(4,1

Using Error 2, you can input a string for a custom error: `solve(4,2,"Uh-Oh!

PortWrite(

PortRead(

solve(7 Copy Variables solve(8 Overwrites variables with new data

Physics

R▶Pr(

This will clear the particle buffer.

R▶Pθ(

This will recalculate the particle positions and draw them. If you want to change the particle buffer, just add a pointer argument. If you want to use a program, for example, as a buffer:

:Get("EBUF→A
:R▶Pθ(A-2

P▶Rx(

This will add a particle to the buffer. Just use the pixel coordinate position. For example: P▶Rx(2,2

P▶Ry(

This will change the particle effect.

That makes it first check down, and if it cannot go down, it then checks left or right, and if it cannot go left or right, it tests up. In decimal, that is 2145, so you would do: P▶Ry(2,2145 To make things easier, though, you can just use a string. This will achieve the same effect: P▶Ry(2,"D,LR,U Note that you do need the actual string, not a pointer.

P▶Rx('

This will convert a rectangular region of the screen to particles. The inputs are P▶Rx('Y,X,Height,Width

This scans the area for pixels that are turned on and adds them to the current particle buffer.

Miscellaneous

>DMS

Found in the angle menu, this is the "module" token. Modules allow you to extend Grammer's functionality. Grammer comes with a default module which must be included to use some functions (like the Menu command).

Currently, you can have up to five other modules. For example, if you have a module packaged as an appvar called MyModule: "5MyModule→>DMS In order to execute a function MyFunc( from one of the modules, use : >DMSMyFunc.

If you have the token hook enabled (from Grammer's main menu), it looks a little cleaner: "5MyModule→$ and $MyFunc, respectively.

conj(

Warning: I have no knowledge of musical jargon, so excuse my mistakes.

This is a sound command with three inputs. The syntax is conj(Note,Octave,Duration Notes are:

Octave is 0 to 6

Duration is in 64th notes. So for example, a 32nd dot note uses 3/64th time. Duration is thus 3.

conj('

This sound routine has several inputs:

This reads data for the period directly to save time (intead of converting numbers on the fly). Size is the size of the data in words, not bytes.

Drawing Commands

These are the drawing commands. Some of these have alternate syntax that do very different things. This section alone is six pages.

DispGraph

Displays the graph screen. You can display another buffer by using a pointer. For example, DispGraphπ9872

Circle(

The syntax is Circle(Y,X,R[,Method[,pattern[,buffer.

This draws a circle using Y and X as pixel coordinates and R as the radius of the circle in pixels. Method is how to draw the circle:

Pattern is a number from 0 to 255 that will be used as a drawing pattern. For example, 85 is 01010101 in binary, so every other pixel will not be drawn. Use 0 for no pattern. If the bit is 0, the pixel will be drawn, if it is 1, it won't be drawn. Buffer is the buffer to draw to (useful with grayscale).

Pt-Off(

This is used to draw sprites to pixel coordinates. It is limited in some ways, compared to the Pt-On( command, but more flexible in others. The syntax is: Pt-Off(Method,DataPointer,Y,X,[Width,[Height[,Buffer

Pt-On(

This also draws sprites, but only to 12 columns (every 8 pixels). This is slightly faster than Pt-Off( and has the advantage of variable width. It also has the DataSwap option that isn't present with the Pt-Off( command. Here is the syntax of the command: Pt-On(Method,DataPointer,Y,X,[Width,[Height[,Buffer

Line('

This is used to draw lines. The syntax for this command is Line('x1,y1,x2,y2[,Method[,Buffer So it is two sets of pixel coordinates and then the Method:

If Method is omitted, it uses 1 as the default.

Text(

Text( has a lot of neat features in Grammer. By default, it uses a 4x6 fixed-width font, and can draw to 24 columns (much like the TI-BASIC Output( command drawing to only 16 columns on the homescreen). Font settings can be modified using the Output( command, including loading custom fixed- and variable-width fonts, and selecting grid-aligned or pixel-aligned drawing. Another feature is that text wraps to the next line and if it goes off the bottom, it wraps to the top.

To draw text, Text(Y,X,"Text. "Text" can be a pointer to a string.

To draw a number, use the ' modifier: Text('Y,X,99

To draw numbers as signed values, set the mode flag with Fix or 32

To draw a number in a specific base (use 2 to 32), add another argument: Text('Y,X,99,16

To draw at the end of the last text drawn, use a degree symbol modifier, ° to replace coordinates: Text(°"Text

Likewise, you can do this with numbers: Text('°99,2 displays 99 in binary

You can use /Text( or Text(r for typewriter text mode (that is the superscript r found at [2nd][APPS]). This will display characters with a delay. The delay is chosen with FixText(. This will even display the individual letters in a token as if it is being typed. Here is an example: /Text(Y,X,"HELLO
And you can use numbers and other operators, too!

To display a char by number, use: Text(Y,X,'#

To draw text as an ASCII string (instead of TI tokens), use ° before the string. For example: Text(Y,X,°"HIrandM(WORLD
That will display the text "HI WORLD" because randM( corresponds to the space char in the ASCII set.

To display 32-bit numbers, the upper and lower 16-bits must be in a pVar. An example where B is the upper 16-bits and C' is the lower 16-bits: :Text('0,0,BC'

Using the Text( command with no arguments returns the X position in Ans and the Y position in Ɵ'.

If you want to draw to coordinates based on the last drawn coordinates, you can do something like this: Text(+3,+0,"Hello. But instead of +0, just leave it empty like this: Text(+3,,"Hello

Line(

This is used to draw rectangles. The syntax for this command is: Line(x,y,Height,Width,Method

Pxl-On(

This turns a pixel on using coordinates (y,x). To draw to a specific buffer, add its pointer as a last argument.

Pxl-Off(

This turns a pixel off using coordinates (y,x). To draw to a specific buffer, add its pointer as a last argument.

Pxl-Change(

This inverts a pixel using coordinates (y,x). To draw to a specific buffer, add its pointer as a last argument.

Pxl-Test(

This returns 0 if the pixel is off, 1 if the pixel is on.

ClrDraw

This clears the graph screen buffer and resets the text coordinates. Optionally, you can clear a specific buffer by putting its pointer directly after. For example, ClrDrawπ9872

ClrHome

This clears the home screen buffer and resets the cursor coordinates

Shade(

This sets the contrast to a value from 0 to 39. 24 is normal and this is not permanent. An example is Shade(30

Horizontal

This draws a horizontal line on the graph. The syntax is Horizontal y[,method,[,Buffer

Vertical

This draws a vertical line on the graph. The syntax is: Vertical x[,method[,Buffer

Tangent(

This is used to shift the screen a number of pixels. The syntax is: Tangent(#ofShifts,Direction[,Buffer # of shifts is the number of pixels to shift the graph screen Direction is represented as a number: 1 = Down 2 = Right 4 = Left 8 = Up You can combine directions by adding the values. For example, Right and Up would be 10 because 2+8=10

Disp

This will let you change the default graph buffer. For example, if you don't want to use the graph screen, you can put this at the start of the program: :Disp π9872 Also, if you are using grayscale, you can use the following: Disp ' will set the back buffer. Dispwill set the front buffer.

Pt-Change(

This command is used to draw tilemaps. There is currently one method, but more should be added in the future. Here is the syntax: Pt-Change(0,MapData,TileData,MapWidth,MapXOffset,MapYOffset,TileMethod

Fill(

Stick around, this is a pretty full command list.

RecallPic

This is used to copy a picture to the current buffer. As an example of its use RecallPic 0. This works for pictures 0 to 255 and archived pics.

StorePic

This stores the contents of the current buffer to a picture. This automatically deletes a preexisting picture. You can use this to store to pictures 0 to 255.

Data Structures

Grammer doesn't really have any data structures which is both good and bad. Bad because it makes you have to think a little more about how to approach a problem, but good in that it allows you to create precisely what you need. This is where you will need commands to create variables, insert or remove data, and edit the data. I will also try to explain how to create some basic data structures like arrays and matrices. First, here are the commands you have to work with:

Memory Access

Get(

This uses a string for the name of an OS var and returns a pointer to its data.

(

Use this to read a byte of data from RAM

{

Use this two read a two byte value from RAM (little endian)

int(

Use this to write a byte of data to RAM.

iPart(

Use this to write a word of data to RAM, little-endian (a word is 2 bytes). For example, to set the first two bytes to 0 in prgmHI:

:Get("EHI→A
:iPart(A,0

Send(

Use this to create Appvars or programs of any size (so long as there is enough memory). For example, to create prgmHI with 768 bytes: Send(768,"EHI.

Programs must be prefixed with "E", protected programs "F" and appvars "U".

Lowercase letters are allowed! :)

[, [[, and [(

This allows you to write multiple bytes to a RAM location. For example, to write some bytes to the address pointed to by A:

:A[1,2,3,4

To store some values as words, you can use ° after the number. These will be stored little endian. For example:

:A[1,2,3°,4

In order to store all values as words, use [[ instead:

:A[[1,2,3,4

To directly store hexadecimal, use [(. For example:

:A[(3C7EFFFFFFFF7E3C

IS>(

This is used to read memory. The argument is one of the pointer vars. It reads the byte pointed to by the pvar and then the pvar is incremented (so consecutive uses will read consecutive bytes). For example, to display the hex of the first four bytes of a var:

:Get("EPROG→Z
:Text('0,0,IS>(Z,16
:Text('°IS>(Z,16
:Text('°IS>(Z,16
:Text('°IS>(Z,16

Archive

Follow this with a var name to archive the var. For example, to archive prgmPROG, do this: Archive "EPROG.

Unarchive

Use this like Archive, except this unarchives the var

Delvar

Use this like Archive, except this will delete a var

sub(

Use this to remove data from a variable. the syntax is: sub(#ofBytes,Offset,"Varname

For example, to delete the first 4 bytes of program Alpha: sub(4,0,"EAlpha

augment(

This is used to insert data into a var. The syntax is: augment(#ofbytes,Offset,"VarName

For example, to insert 4 bytes at the beginning of appvar Hello: augment(4,0,"UHello

Data Structures, continued

Now let's make an array! First you need to know what you want. Do you want to have 2-byte pieces of data or 1-byte? I like using one byte, so here is what we do:

:.0:Return
:Send(256,"VDat→Z   ;We create a TempProg with 256 bytes of data called Dat.
:Z[rand,rand,rand   ;write 3 random bytes.
:ClrDraw
:For(3
:Text('°Is<(Z       ;Display the value at byte Z. Also increments Z.
:Text('°",
:DispGraph
:End
:Stop

That didn't really need a 256-byte variable, but I figured I would show how to make one. Anyways, what that did was make a 256-byte tempprog (which the OS automatically deletes once control is returned to the OS and you are on the homescreen). Then, we stored 3 random values to the first three bytes, then we displayed those values with commas after each number. If you want to use that 256 bytes for a matrix, instead, you can make it a 16x16 matrix and access elements using a formula. For example, to read (Y,X): :(Z+X+Y*16 That means that the data is stored in rows. That is why we take the row number and multiply by 16 (that is the number of elements per row). This happens to be the syntax that tilemaps are stored (stored in rows).

Miscellaneous

Modes

Fix Text(

Use this to set the typewriter delay. The larger the number, the slower the typewriter text is displayed.

Fix

Use this to set certain modes. For all the modes that you want to set, add the corresponding values together. For example, to enable inverse text and inverse pixels, use Fix 1+2 or simply Fix 3

Here are the modes:

If you want to use bit logic to set or obtain specific bits or info about the current modes, you can do things like this:

Stores the current mode value:

:Fix →A

Set the first three modes without changing the rest:

:Fix or 7

Toggles mode 4 (enable/disable [ON] key)

:Fix xor 4

Full

This is used to set 15MHz mode. Alternatively, if you add a number to the end:

15MHz is only set if it is possible for the calc. This returns 0 if the previous speed setting was 6MHz, 1 if it was 15MHz. This gives us a way to determine if 15MHz is possible:

:Full     ;Sets 15MHz if possible
:If Full  ;Sets 15MHz if possible, but also returns 1 if the previous `Full` was able to set 15MHz
:Then
:Text(0,0,"15MHz possible!
:Else
:Text(0,0,"6MHz only :(
:End

Output(

This is used to change the font. The syntax is:

The output is a pointer to the fontset (custom or standard set), which could be useful if you wanted to read or process the built-in set.

For Output(3, remember that Omnicalc's font data starts at an offset of

  1. So if you have a font called BOLD, you would do: Output(3,11+Get("EBOLD

Binary Lesson

This document was designed to explain the basics of Decimal (our number system), Hexadecimal (base16, the ASM number system), and binary (machine code, 0's and 1's). Again, this is going to be very basic. Check the internet if you want to learn more.

Converting from Dec to Hex:

  1. Divide the number by 16. The remainder is the first number. If it is 0 to 9, just keep that. If it is 10 to 15, use letters A to F.

  2. If the number is 16 or larger, still, divide by 16.

  3. Repeat step 1 and 2 until finished.

Here is an example of 32173 converted to Hex:

32173/16= 2010 13/16  Remainder=13 “D”
2010/16= 125 10/16    Remainder=10 “A”
125/16= 7 13/16       Remainder=13 “D”
7/16= 7/16            Remainder=7  “7”

So the number is 7DADh

Converting from Hex to Dec:

I will start this with an example of 731h:

1*16^0 = 1
3*16^1 = 48
7*16^2 = 1792

Add them all up to get 1841. Did you see the pattern with the 16n?

Binary.

Converting to and from binary is pretty similar. Just replace all the 16's with 2's and you will have it.

Octal.

Replace all the 16's with 8's.

Other Bases

Replace the 16's with whatever number you want.

Here is some cool knowledge for spriting. Each four binary digits represents one hexadecimal digit. For example: 00110101 corresponds to 35 in hexadecimal. This makes it super easy to convert a sprite which is binary to hexadecimal! You only need the first 16 digits, so here you go:

0000 = 0 0100 = 4 1000 = 8 1100 = C
0001 = 1 0101 = 5 1001 = 9 1101 = D
0010 = 2 0110 = 6 1010 = A 1110 = E
0011 = 3 0111 = 7 1011 = B 1111 = F

Charts

Key Codes

You can use this as a guide to the key values output by getKey example, Clear=15

Key Codes

Also, there are the diagonal directions:
5=Down+Left
6=Down+Right
7=Up+Left
8=Up+Right
16=All directions mashed

Data Types

#  name     You use:
00=Real         log(    Real Format
01=List         A       Real Format
02=Matrix       B       Real Format
03=EQU          C       Symbol Var
04=String       D       Symbol Var
05=Program      E       Named Var
06=ProtProg     [       Named Var
07=Picture      ]       Symbol Var
08=GDB          {       Symbol Var
09=Unknown      }       Not Supported
10=UnknownEqu   J       Not Supported
11=New EQU      K       Not Supported
12=Complex      L       Real Format
13=Complex List M       Real Format
14=Undefined    N       Not Supported
15=Window       O       Not Supported
16=ZSto         0       Not Supported
17=Table Range  1       Not Supported
18=LCD          2       Not Supported
19=BackUp       3       Not Supported
20=App          4       Not Supported
21=Appvar       5       Named Var
22=TempProg     6       Named Var
23=Group        7       Named Var   this can mess stuff up unless you *really* know what you are doing.

Symbol Vars are compatible with each other. Named Vars are compatible with each other. Real Format variables are a special format generally not supported by Grammer.

Examples

Here are some code examples to hopefully help you. Some are really short snippets of code, others are longer pieces. Movement Here is code that changes X and Y based on key presses. :X+getKey(3 :min(-getKey(2,95→X :Y+getKey(1 :min(-getKey(4,63→YParticles :.0: :0→X→Y :Repeat getKey(15 :R▶Pθ( :If getKey(9 :P▶Rx(Y,X :X+getKey(3 :min(-getKey(2,95→X :Y+getKey(1 :min(-getKey(4,63→Y :End :Stop

Thanks

I have to give special thanks to Yeongjin Nam for his work on writing a better tutorial for Grammer and as well Louis Becquey (persalteas) for his work on writing a french readme/tutorial. Both of them have also made many valuable suggestions that have helped make Grammer what it is right now. Thanks much!

I also thank Hans Burch for reconstructing Grammer 2 after I lost my work. It must have been a tremendous amount of effort and tedium, and I greatly appreciate it.

Finally, I would like to thank the sites that have let me get the word out about this project, especially Omnimaga and Cemetech.