Chess AI

History:
    1.10 - First NATIVE AmigaOS 4.1 release (PPC). The game evolved
           from the 68k/OS3 version; this is a separate, native PPC
           build - engine and GUI run in a single process. (July 2026)
           New in the OS4 version:
           - Six screen modes: windowed and fullscreen at 640x480,
             800x600 and 1024x768
           - Ten difficulty levels named after Amiga models
             (A1000 Pioneer ... A4000T Ultimate)
           - 120-second per-move time limit added
           - Four piece sets in-menu: Crystal, Classic, Amber, Marble
           - Highlights toggle to switch off all square highlighting
           - Hint added to the Help menu (next to the H key)
           - Transposition table up to 16 MB, auto-sized to free RAM
           - Fixed X1000/X5000 freeze, red king-in-check highlight,
             two-square hint, progress bar on truecolor Workbench,
             two-digit level display, and move ordering at high levels

    ---- earlier 68k / AmigaOS 3.x history ----
    1.06a- removal of a minor bug that prevented the game from launching
    1.06 - Added CyberGraphics (cybergraphics.library) support alongside
           Picasso96. Single binary auto-detects available RTG system.
           Numerous bugfixes: knight animation (pieces disappearing under
           knight), percentage display during AI thinking, last move
           highlight for black pieces, debug output removed. (July 2026)
    1.05 - RTG version (Picasso96, 16-bit HiColor, 640x480/800x600).
           Crystal Staunton pieces from BMP. Built-in 8x14 bitmap font.
           Thank you, Domenico Lattanzi, for identifying the bug and
           helping to fix the castling issue involving the king and rook.
           (May 2026)
    1.04 - 4 piece sets, opening book 14 variants, full SEE, level 7,
           hint key (H), PGN date+result, critical move_pool bugfix
           (May 2026)
    1.03 - Improved evaluation, check extension, adaptive null-move,
           extended futility pruning depth 3, aggressive LMR (May 2026)
    1.02 - First 68040/68060 binary. Single binary auto-detects CPU.
           Level 6 Master added (May 2026)

--- ENGLISH -------------------------------------------------------

Native AmigaOS 4.1 chess game for Amiga computers with a PowerPC
processor and an RTG graphics card. The engine runs in the same
process as the interface - no 68k emulation.

This is the first native OS4 release. The game evolved from the
68k/AmigaOS 3.x version, but this is a separate, standalone PPC
build - not a replacement for the 68k edition.

Requires AmigaOS 4.1 and at least 32 MB RAM.
Developed and compiled natively on an Amiga 1200 with Blizzard PPC
300 MHz and BVision. Also tested on AmigaOne X1000 and X5000.

Use Chess_RTG_Prefs to select the screen mode.

This project is proof that Claude AI (Anthropic) handles Amiga C
programming surprisingly well. The Amiga community finally has a new
native OS4 chess game in 2026!

Features:
- Native PPC binary for AmigaOS 4.1, RTG graphics
- Six screen modes: windowed and fullscreen at 640x480, 800x600, 1024x768
- Four piece sets loaded from BMP, switchable in-game:
  Crystal, Classic, Amber, Marble
- Wood gradient chessboard loaded from board.bmp
- Built-in 8x14 bitmap font (no dependency on system fonts)
- 3D gradient highlights for selection, legal moves and last move
- Highlights toggle (turn off all square highlighting)
- Hint (H key or Help menu) - highlights source and destination squares
- Progress bar and Skip button during AI thinking
- Negamax alpha-beta engine with iterative deepening
- Quiescence search, aspiration windows
- Full SEE (Static Exchange Evaluation) for accurate capture ordering
- Improved evaluation: passed pawns, doubled pawns, bishop pair,
  rooks on open files, connected rooks, king pawn shield
- Null-move pruning with adaptive R (R=2 depth<5, R=3 depth>=5)
- Check extensions, aggressive LMR
- Extended Futility Pruning: depth 1=330cp, depth 2=500cp, depth 3=900cp
- Razoring at depth 1
- Transposition table (Zobrist hashing, auto-sized to free RAM, up to 16 MB)
- Move ordering: PV, SEE, killer moves, history heuristic
- Piece-square tables (middlegame + endgame)
- Opening book: 14 openings with weighted random selection (default ON)
  Italian Game, Ruy Lopez, Sicilian, French, Caro-Kann, Queen's Gambit,
  King's Indian, Nimzo-Indian, English, London, Scotch, Pirc,
  King's Gambit, Reti
- 10 difficulty levels named after Amiga models:
    1-A1000 Pioneer, 2-A500 Classic, 3-A2000 Workstation,
    4-A2500 Accelerator, 5-A3000 Pro, 6-A500+ Enhanced,
    7-A600 Compact, 8-A1200 AGA, 9-A4000 Power, 10-A4000T Ultimate
  Default: level 5 (A3000 Pro)
- Time limits per move: none / 30s / 60s / 90s / 120s
- Player vs AI / Player vs Player / AI vs AI modes
- PGN save/load with real date (from Amiga clock) and result
- Move history, Undo/Redo
- Game timer with pause (P key)
- Force move: N key or Skip button
- Settings saved to PROGDIR:Chess.prefs
- GadTools menus, English interface

A note on strength:
  This is NOT the strongest chess engine on the Amiga, and it is far
  weaker than Stockfish and other top engines on modern PCs. It is a
  complete, modern program (alpha-beta with pruning, transposition
  table, opening book) built to be an enjoyable opponent running
  natively on Amiga PPC - a solid challenge for most club players,
  especially at the higher levels.

Installation:
  Copy all files to any directory and run Chess_RTG_Prefs first
  to select your screen mode. Then run Chess_RTG_OS4.

  Required files:
    Chess_RTG_OS4    - main executable (native PPC)
    Chess_RTG_Prefs  - preferences program
    pieces1.bmp .. pieces4.bmp - the four piece sets
    pieces.bmp       - fallback piece set
    board.bmp        - board graphic

Created with Claude AI (Anthropic) by Benedykt Dziubaltowski.
Public Domain.

--- POLSKI --------------------------------------------------------

Natywna gra szachowa dla AmigaOS 4.1, przeznaczona dla Amigi z
procesorem PowerPC i karta graficzna RTG. Silnik dziala w tym samym
procesie co interfejs - bez emulacji 68k.

To pierwsza natywna wersja OS4. Gra wyewoluowala z wersji 68k/AmigaOS
3.x, ale jest to osobny, samodzielny build PPC - nie zastepuje wersji
68k.

Wymaga AmigaOS 4.1 i co najmniej 32 MB RAM.
Tworzona i kompilowana natywnie na Amiga 1200 z Blizzard PPC 300 MHz
i BVision. Testowana takze na AmigaOne X1000 i X5000.

Uzyj Chess_RTG_Prefs aby wybrac tryb ekranu.

Funkcje:
- Natywna binarka PPC dla AmigaOS 4.1, grafika RTG
- Szesc trybow ekranu: okno i pelny ekran w 640x480, 800x600, 1024x768
- Cztery zestawy figur ladowane z BMP, przelaczane w grze:
  Crystal, Classic, Amber, Marble
- Szachownica z gradientem drewna ladowana z board.bmp
- Wbudowana czcionka bitmapowa 8x14
- Podswietlenia 3D z gradientem dla wyboru, legalnych ruchow i ostatniego ruchu
- Przelacznik Highlights (wylaczenie wszystkich podswietlen)
- Hint (klawisz H lub menu Help) - podswietla pole zrodlowe i docelowe
- Pasek postepu i przycisk Skip podczas myslenia AI
- Silnik negamax alpha-beta z iteracyjnym poglebianiem
- Quiescence search, okna aspiracyjne, pelny SEE
- Lepsza ewaluacja: wolne piony, podwojone piony, para goncow,
  wiezy na otwartych liniach, polaczone wiezy, tarcza pionkowa krola
- Null-move pruning, rozszerzenia szachowe, LMR, Futility, Razoring
- Tablica transpozycji (rozmiar dobierany wg wolnego RAM, do 16 MB)
- Ksiazka debiutowa: 14 wariantow (domyslnie WL)
- 10 poziomow trudnosci nazwanych od modeli Amigi:
    1-A1000 Pioneer, 2-A500 Classic, 3-A2000 Workstation,
    4-A2500 Accelerator, 5-A3000 Pro, 6-A500+ Enhanced,
    7-A600 Compact, 8-A1200 AGA, 9-A4000 Power, 10-A4000T Ultimate
  Domyslny: poziom 5 (A3000 Pro)
- Limity czasu na ruch: brak / 30s / 60s / 90s / 120s
- Tryby: Gracz vs AI / Gracz vs Gracz / AI vs AI
- Zapis/odczyt PGN z data i wynikiem
- Historia ruchow, Cofanie/Ponowienie
- Timer partii z pauza (klawisz P)
- Wymuszanie ruchu: klawisz N lub przycisk Skip
- Ustawienia zapisywane do PROGDIR:Chess.prefs
- Menu GadTools, interfejs angielski

Uwaga o sile gry:
  To NIE jest najsilniejszy silnik szachowy na Amige i jest znacznie
  slabszy niz Stockfish oraz czolowe silniki na wspolczesnych pecetach.
  Jest to kompletny, nowoczesny program (alpha-beta z przycinaniem,
  tablica transpozycji, ksiazka debiutowa) stworzony jako przyjemny
  przeciwnik dzialajacy natywnie na Amiga PPC - solidne wyzwanie dla
  wiekszosci graczy klubowych, zwlaszcza na wyzszych poziomach.

Instalacja:
  Skopiuj wszystkie pliki do dowolnego katalogu. Uruchom Chess_RTG_Prefs
  aby wybrac tryb ekranu, nastepnie uruchom Chess_RTG_OS4.

Stworzone z pomoca Claude AI (Anthropic) przez Benedykta Dziubaltowskiego.
Public Domain.

--- MAGYAR --------------------------------------------------------

Nativ sakkjatek AmigaOS 4.1 rendszerhez, PowerPC processzoru es RTG
grafikus kartyaju Amigara. A motor ugyanabban a folyamatban fut, mint
a felulet - 68k emulacio nelkul.

Ez az elso nativ OS4 valtozat. A jatek a 68k/AmigaOS 3.x valtozatbol
fejlodott, de ez egy kulonallo, onallo PPC build - nem valtja fel a
68k kiadast.

AmigaOS 4.1 es legalabb 32 MB RAM szukseges.
Egy Amiga 1200 gepen keszult es fordult nativan, Blizzard PPC 300 MHz
kartyaval es BVision karyaval. Tesztelve AmigaOne X1000 es X5000 gepeken is.

Hasznalja a Chess_RTG_Prefs programot a kepernyomod kivalasztasahoz.

Funkciok:
- Nativ PPC binaris AmigaOS 4.1 rendszerhez, RTG grafika
- Hat kepernyomod: ablakos es teljes kepernyos 640x480, 800x600, 1024x768
- Negy babukeszlet BMP-bol betoltve, jatek kozben valthato:
  Crystal, Classic, Amber, Marble
- Fa gradiens sakktabla board.bmp-bol betoltve
- Beepitett 8x14 bitmap betukeszlet
- 3D gradiens kiemelesek kivalasztashoz, szabalyos lepesekhez, utolso lepeshez
- Highlights kapcsolo (minden mezokiemeles kikapcsolasa)
- Hint (H billentyu vagy Help menu) - kiemeli a kiindulo es celmezot
- Haladasjelzo es Skip gomb az AI gondolkodasa kozben
- Negamax alfa-beta motor iterativ melyitessel
- Quiescence kereses, aspiracios ablakok, teljes SEE
- Jobb kiertekeles: szabad gyalogok, kettozott gyalogok, futopar,
  bastya nyitott vonalakon, kapcsolt bastya, kiraly gyalog-pajzs
- Null-move pruning, sakk-kiterjesztesek, LMR, Futility, Razoring
- Transzpozicios tabla (meret a szabad RAM alapjan, legfeljebb 16 MB)
- Megnyitokonyv: 14 valtozat (alapert. BE)
- 10 nehezsegi szint Amiga modellekrol elnevezve:
    1-A1000 Pioneer, 2-A500 Classic, 3-A2000 Workstation,
    4-A2500 Accelerator, 5-A3000 Pro, 6-A500+ Enhanced,
    7-A600 Compact, 8-A1200 AGA, 9-A4000 Power, 10-A4000T Ultimate
  Alapertelmezett: 5. szint (A3000 Pro)
- Idokorlat lepesenkent: nincs / 30s / 60s / 90s / 120s
- Modok: Jatekos vs AI / Jatekos vs Jatekos / AI vs AI
- PGN mentes/betoltes datummal es eredmennyel
- Lepestortenet, Visszavonas/Ujravegrehajtas
- Parti idomero szunettel (P billentyu)
- Lepes kikenyszeritese: N billentyu vagy Skip gomb
- Beallitasok: PROGDIR:Chess.prefs
- GadTools menu, angol felhasznaloi felulet

Megjegyzes a jatekerorol:
  Ez NEM a legerosebb sakkmotor Amigan, es sokkal gyengebb, mint a
  Stockfish es a mai szamitogepek elvonalbeli motorjai. Teljes erteku,
  modern program (alpha-beta nyesessel, transzpozicios tablaval,
  megnyitokonyvvel), amely elvezetes ellenfelnek keszult nativan Amiga
  PPC hardveren - komoly kihivas a legtobb klubjatekos szamara,
  kulonosen a magasabb szinteken.

Telepites:
  Masold az osszes fajlt barmely konyvtarba. Futtasd a Chess_RTG_Prefs
  programot a kepernyomod kivalasztasahoz, majd inditsd el a
  Chess_RTG_OS4 programot.

Keszult Claude AI (Anthropic) kozremukodesevel,
Dziubaltowski Benedek altal. Public Domain.

--- CREDITS -------------------------------------------------------

- Rafal "Mufa" Chyla - OS4 beta testing, found the X1000/X5000 freeze,
  patient testing of the high difficulty levels
- Domenico Lattanzi - identifying and helping fix the castling bug
  (king and rook) in the 68k version
- Marcel van Kervinck - author of MSCP, the inspiration for the
  engine architecture
- Anthropic / Claude AI - collaboration on the implementation
- The Amiga community - for keeping the platform alive for decades