UltimateBasic 64 1.5.3

Ultimate Basic v1.5.3 – Release Notes

2026-08-18 – Multi-dimensional arrays

• Arrays can now be declared with more than one dimension using a
  comma-separated dimension list, for both byte and word arrays:
  var grid = array(8, 8) # 8x8 = 64 bytes
  var wm = array_word(4, 4) # 4x4 word elements = 32 bytes
• Elements are indexed with a comma-separated subscript list and stored
  row-major; the flat offset is base + i0*(d1*..) + i1*(d2*..) + ... :
  grid[row, col] = 42
  var v = grid[row, col]
• Any number of dimensions is supported. Dimensions must be compile-time
  constants (integer literals or const values).
• When every subscript is a constant the address is folded at compile time to a
  single absolute store/load; a variable subscript emits the row*stride + col
  computation followed by an indexed (ptr),Y access.
• A single subscript into a multi-dimensional array is still allowed and is
  treated as a flat/linear index (e.g. grid[10]).
• Indexing with a subscript count that is neither 1 nor the declared rank is
  reported as a compile-time error.
• Implemented entirely in the parser (multi-index folds to one flat index
  expression), so code generation is unchanged.
• Added examples/array2d_demo.ub and integration tests covering constant and
  variable indices, row-major layout, word-element stride, linear access,
  const-derived dimensions, and the wrong-rank error.

2026-08-18 – PETSCII bracket encoding fix

• Fixed string encoding of the '[' , ']' and '^' characters, which previously
  fell through to the unknown-character placeholder and printed as '?'.
• They now emit their correct C64 codes ($5B, $5D, $5E). These code points are
  identical in the uppercase/graphics and lowercase charsets, so the fix is
  correct in both uppercase and lowercase modes.
• Added a regression test for bracket encoding in both charset modes.