MICRO-SOKOBAN 1.2

MICRO-SOKOBAN 1.2 — Apple II+

MICRO-SOKOBAN 1.2 is a bootable DOS 3.3 disk image for the Apple II+ with 48 KB RAM and later Apple II models. Download MICRO-SOKOBAN.dsk, mount it as a 5¼-inch disk, and boot it. The disk contains all 454 Microban I–IV puzzles and the five introductory lessons; no installation is needed.

What's new since 1.1

• Two-voice title music: the title tune now has a walking bass under its melody, both on the built-in one-bit speaker, and runs ten bars (about 24 seconds) instead of three before it loops. MENU SOUND still controls it. A key or a button cuts the note being played at once.
• COLOR MODE: a new switch in OPTIONS gives crates on goals their filled green body back. It is off by default: on a monochrome display orange and green look the same, and the hollow frame with a check mark remains the readable choice there.
• Steadier title: the corridor animation now steps between two beats of the music instead of delaying a note.

Saved games, records, profiles and options from 1.1 disks keep working: the new switch uses a spare bit of the options byte.

Screenshots

OPTIONS with COLOR MODE	A crate on its goal in COLOR MODE

How the two voices work

The Apple II speaker has one bit. The player looks at the bass, then at the melody, 31,000 times a second: while both square waves are at the same level the speaker rests there, and while they differ it flips at every look. That carrier is too fast to hear; what remains is the sum of the two waves. Every path through the loop takes the same 33 cycles, so pitches are whole counts of turns, and the tune is written in the just scale of F, whose periods are whole.

Playing

Use I/J/K/L, W/A/S/D, the arrow keys, or a joystick to move. U undoes, Y redoes, R restarts the level, ESC opens the menu, and H opens help. The menu provides the tutorial, profiles, restart, level selection, options, the Hall of Fame, and exit to DOS; everything on screen is in English.

The game keeps ten independent player profiles, saved puzzle positions and records, and a 1,024-move Undo/Redo history during play. The collections are unchanged: 150, 122, 92 and 90 puzzles from David W. Skinner's Microban I–IV, with their original numbers.

Validation and credits

The release disk was rebuilt from a clean tree and compared byte-for-byte with the committed image. Automated emulator tests cover all 454 puzzles, the five tutorial lessons, solution playback, video-page restoration, menu navigation, saved positions, profiles, ranking, write-protected media, and return to BASIC. New in this version: the tests listen to the title music (both voices at their pitch and level, ten steady bars, a key cutting a note) and check the colour-mode tile on screen and its option across a reboot. These checks validate emulated Apple II execution; the two-voice music has not yet been heard on real hardware.

Puzzle collections: David W. Skinner, distributed with credit. Apple II adaptation: VERHILLE Arnaud. Source code is available under GPL-3.0. The full manual in the repository is in French.