Letters on Tiles

The tiles are empty. This unit fills them — one letter at a time, with a rising tone on each. This animated reveal is the game’s signature visual moment, and it’s built from one new idea: string slicing.

Reaching Inside a String

  10 LET w$="planet"
  20 PRINT "Word: ";w$
  30 PRINT "First letter: ";w$(1 TO 1)
  40 PRINT "Third letter: ";w$(3 TO 3)
  50 PRINT "Letters 2 to 4: ";w$(2 TO 4)
  60 FOR i=1 TO LEN w$
  70 PRINT w$(i TO i);" ";
  80 NEXT i

w$(1 TO 1) extracts the first character. w$(3 TO 3) extracts the third. w$(2 TO 4) pulls three characters from the middle. The numbers are positions, starting at 1, and TO marks the range.

For a single character at position i, use w$(i TO i). Put that inside a FOR loop and you can walk through every letter in the word.

The Animated Reveal

   5 BORDER 0: PAPER 0: INK 7: CLS
  10 FOR i=0 TO 31
  12 PRINT AT 0,i; PAPER 2;" "
  14 NEXT i
  16 PRINT AT 0,8; PAPER 2; INK 7; BRIGHT 1;" WORD SCRAMBLE "
  20 PRINT AT 4,10; INK 5;"Unscramble:"
  30 LET w$="planet"
  32 LET c=(32-LEN w$*2)/2
  34 FOR i=1 TO LEN w$
  36 PRINT AT 8,c+i*2-2; PAPER 1;" "
  38 PRINT AT 9,c+i*2-2; PAPER 1;" "
  40 NEXT i
  50 FOR i=1 TO LEN w$
  52 PRINT AT 8,c+i*2-2; PAPER 1; INK 6; BRIGHT 1;w$(i TO i)
  54 BEEP 0.05,5+i*2
  56 NEXT i

Each letter appears on its blue tile with a rising BEEP. The loop on lines 50-56 does the work:

• w$(i TO i) extracts the character at position i
• PRINT AT 8, c + i * 2 - 2 places it on the correct tile
• PAPER 1; INK 6; BRIGHT 1 prints bright yellow on blue
• BEEP 0.05, 5 + i * 2 plays a note that rises with each letter

The pitch formula 5 + i * 2 means the first letter plays at pitch 7, the second at 9, the third at 11 — a climbing scale that builds anticipation. When the last letter lands, the word is complete.

Why TO and Not Just a Number?

On many computers, w$(3) gives you the third character. On the Spectrum, w$(3) is shorthand for w$(3 TO 3) — it works, but the TO syntax is more flexible. w$(2 TO 5) gives you four characters in one go. You’ll use longer ranges in the next unit.

Try This

Slower reveal. Change BEEP 0.05 to BEEP 0.15 for a more dramatic, slower appearance. Each letter hangs in the air before the next arrives.

Descending pitch. Replace 5 + i * 2 with 20 - i * 2. The notes fall instead of rising — a different mood entirely.

What You’ve Learnt

• String slicing — w$(i TO i) extracts a single character at position i
• Ranges — w$(2 TO 4) extracts characters 2 through 4
• Animated reveal — a FOR loop placing one character at a time with BEEP
• Rising pitch — 5 + i * 2 creates an ascending tone sequence