Hello World! with scrolly text (if you like).

/** This does something similar to the classic
 *  "Hello World!" code that's a popular starting
 *  point for learning programming. It also adds
 *  a scrolly text at the bottom of the screen.
 *  For the Sinclair ZX Spectrum using z88dk
 *  MMXII Donkeysoft. */
#include <stdio.h>
#include <input.h>
//#include <spectrum.h>
// Here are our default colour attributes
#define INK     7
#define PAP     2
#define FLA     0
#define BRI     1
#define INV     0
#define BOR     5
// This is used in the setup function, which drops into
// machine code - see my blog for more information:
#define COL     128*FLA+64*BRI+8*PAP+INK
// Forward declarations of functions:
static void main(void);
static void setup(void);
static void hello(void);
static void magazine(void);
static void scroll(void);
// Global variables:
static int c=0;
static int i=0;
static int j=0;
// Here is an array which will set up the default colour
// attributes for printing our message to the screen,
// 255 is used as a 'terminator' to say "we've finished here"
static int screensetup[]=
{
    1,32,16,48+INK,17,48+PAP,18,48+FLA,19,BRI,20,48+INV,12,255
};
static int scrollsetup[]=
{
    1,64,16,48+INK-1,22,0,5,255
};
static char text[]="................ This is an example of a simple scrolly text in C           #"; // Hash used as terminator!
static char buffer=' ';
// This is the 'entry point' of our program:
void main(void)
{
    // This will call a routine to set the default
    // colour arrtibutes for the whole screen as
    // defined above:
    setup();
    // This does the same for outputting out character
    // see http://www.z88dk.org/wiki/doku.php?id=platform:zx
    // for more information under the heading "The standard
    // ZX Spectrum console driver" - hopefully, these numbers
    // will now make more sense!
    while(screensetup[i]!=255)
    {
        // The %c means 'print character code' or something similar
        printk("%c",screensetup[i]);
        // Increase i to read the next element of the array:
        i=i+1;
    }
    i=0;
    // Calls our functions, firstly hello:
    hello();
    // and now magazine:
    magazine();
    // This should set up our next lot of text as specified in the
    // look-up table aka array called scrollsetup:
    while(scrollsetup[i]!=255)
    {
        printk("%c",scrollsetup[i]);
        i=i+1;
    }
    // This simply waits for a key to be pressed:
    in_WaitForKey();
    // This invokes an infinite loop:
    while(1)
    {
        // Here is the time we'll wait in milliseconds:
        in_Wait(48);
        // This effectively moves the cursor or something:
        printf("\x16\x37\x20");
        printf(" ");
        // Here's our loop, as we're going to print out 64 characters
        // now instead of 32:
        for(c=0;c<62;c=c+1)
        {
            // Okay, we want to print all of the chatacters in the
            // scrolly text except for the hash as we're using that
            // as a terminator to say 'end of string':
            if(text[c]!="#")
            {
                printf("%c",text[c]);
            }
        }
        // This calls our scroll function:
        scroll();
    }
}
// This function sets up the default colours for our screen as
// defined above:
void setup(void)
{
    #asm
    // Sets default ink and paper colour, then clears screen
    ld a,COL
    ld (23693),a
    call 3503
    // Sets border colour
    ld a,BOR
    call 8859
    #endasm
}
void hello(void)
{
    // Here is where the magic happens, can you tell what it does?
    printf("Hello ");
}
void magazine(void)
{
    // And what about this bad boy then?
    printf("Magazine!\n");
}
void scroll(void)
{
    // Sets counter to zero
    c=0;
    // The buffer will preserve the first char otherwise the
    // scrolling won't wrap around
    buffer=text[c];
    // Loop will happen whilst the terminator hasn't been reached:
    while(text[c]!='#')
    {
        // Moves each character one element to the left:
        text[c]=text[c+1];
        // Increase our counter
        c=c+1;
    }
    // Puts the old first character from the start to the end so
    // it wraps around:
    text[c-1]=buffer;
    // Checks to see if the terminator has been over-written, if not
    // then it's restored:
    if(text[c]!='#')
    {
        text[c]='#';
    }
}