You guys are so lucky. I used to own this book back in the day. Now it is online for free. I think the last publication was 1983.
http://www.atariarchives.org/mlb/
Here is part of the code from a game called microchess:
Code:
;***********************************************************************
;
; MicroChess (c) 1996-2002 Peter Jennings, peterj@benlo.com
;
;***********************************************************************
; I have been given permission to distribute this program by the
; author and copyright holder, Peter Jennings. Please get his
; permission if you wish to re-distribute a modified copy of
; this file to others. He specifically requested that his
; copyright notice be included in the source and binary images.
; Thanks!
;
; modified by Daryl Rictor to work over a serial terminal connection, August 2002.
;
; 6551 I/O Port Addresses
;
ACIADat = $7F70
ACIASta = $7F71
ACIACmd = $7F72
ACIACtl = $7F73
;
; page zero variables
;
BOARD = $50
BK = $60
PIECE = $B0
SQUARE = $B1
SP2 = $B2
SP1 = $B3
INCHEK = $B4
STATE = $B5
MOVEN = $B6
REV = $B7
OMOVE = $DC
WCAP0 = $DD
COUNT = $DE
BCAP2 = $DE
WCAP2 = $DF
BCAP1 = $E0
WCAP1 = $E1
BCAP0 = $E2
MOB = $E3
MAXC = $E4
CC = $E5
PCAP = $E6
BMOB = $E3
BMAXC = $E4
BMCC = $E5 ; was BCC (TASS doesn't like it as a label)
BMAXP = $E6
XMAXC = $E8
WMOB = $EB
WMAXC = $EC
WCC = $ED
WMAXP = $EE
PMOB = $EF
PMAXC = $F0
PCC = $F1
PCP = $F2
OLDKY = $F3
BESTP = $FB
BESTV = $FA
BESTM = $F9
DIS1 = $FB
DIS2 = $FA
DIS3 = $F9
temp = $FC
;
;
;
*=$1000 ; load into RAM @ $1000-$15FF
LDA #$00 ; REVERSE TOGGLE
STA REV
JSR Init_6551
CHESS CLD ; INITIALIZE
LDX #$FF ; TWO STACKS
TXS
LDX #$C8
STX SP2
;
; ROUTINES TO LIGHT LED
; DISPLAY AND GET KEY
; FROM KEYBOARD
;
OUT JSR pout ; DISPLAY AND
JSR KIN ; GET INPUT *** my routine waits for a keypress
; CMP OLDKY ; KEY IN ACC *** no need to debounce
; BEQ OUT ; (DEBOUNCE)
; STA OLDKY
;
CMP #$43 ; [C]
BNE NOSET ; SET UP
LDX #$1F ; BOARD
WHSET LDA SETW,X ; FROM
STA BOARD,X ; SETW
DEX
BPL WHSET
LDX #$1B ; *ADDED
STX OMOVE ; INITS TO $FF
LDA #$CC ; Display CCC
BNE CLDSP
;
NOSET CMP #$45 ; [E]
BNE NOREV ; REVERSE
JSR REVERSE ; BOARD IS
SEC
LDA #$01
SBC REV
STA REV ; TOGGLE REV FLAG
LDA #$EE ; IS
BNE CLDSP
;
NOREV CMP #$40 ; [P]
BNE NOGO ; PLAY CHESS
JSR GO
CLDSP STA DIS1 ; DISPLAY
STA DIS2 ; ACROSS
STA DIS3 ; DISPLAY
BNE CHESS
;
NOGO CMP #$0D ; [Enter]
BNE NOMV ; MOVE MAN
JSR MOVE ; AS ENTERED
JMP DISP
NOMV CMP #$41 ; [Q] ***Added to allow game exit***
BEQ DONE ; quit the game, exit back to system.
JMP INPUT ; process move
DONE JMP $FF00 ; *** MUST set this to YOUR OS starting address
;
; THE ROUTINE JANUS DIRECTS THE
; ANALYSIS BY DETERMINING WHAT
; SHOULD OCCUR AFTER EACH MOVE
; GENERATED BY GNM
;
;
;
JANUS LDX STATE
BMI NOCOUNT
;
; THIS ROUTINE COUNTS OCCURRENCES
; IT DEPENDS UPON STATE TO INDEX
; THE CORRECT COUNTERS
;
COUNTS LDA PIECE
BEQ OVER ; IF STATE=8
CPX #$08 ; DO NOT COUNT
BNE OVER ; BLK MAX CAP
CMP BMAXP ; MOVES FOR
BEQ XRT ; WHITE
;
OVER INC MOB,X ; MOBILITY
CMP #$01 ; + QUEEN
BNE NOQ ; FOR TWO
INC MOB,X
;
NOQ BVC NOCAP
LDY #$0F ; CALCULATE
LDA SQUARE ; POINTS
ELOOP CMP BK,Y ; CAPTURED
BEQ FOUN ; BY THIS
DEY ; MOVE
BPL ELOOP
FOUN LDA POINTS,Y
CMP MAXC,X
BCC LESS ; SAVE IF
STY PCAP,X ; BEST THIS
STA MAXC,X ; STATE
;
LESS CLC
PHP ; ADD TO
ADC CC,X ; CAPTURE
STA CC,X ; COUNTS
PLP
;
NOCAP CPX #$04
BEQ ON4
BMI TREE ;(=00 ONLY)
XRT RTS
;
; GENERATE FURTHER MOVES FOR COUNT
; AND ANALYSIS
;
ON4 LDA XMAXC ; SAVE ACTUAL
STA WCAP0 ; CAPTURE
LDA #$00 ; STATE=0
STA STATE
JSR MOVE ; GENERATE
JSR REVERSE ; IMMEDIATE
JSR GNMZ ; REPLY MOVES
JSR REVERSE
;
LDA #$08 ; STATE=8
STA STATE ; GENERATE
; JSR OHM ; CONTINUATION
JSR UMOVE ; MOVES
;
JMP STRATGY ; FINAL EVALUATION
NOCOUNT CPX #$F9
BNE TREE
;
; DETERMINE IF THE KING CAN BE
; TAKEN, USED BY CHKCHK
;
LDA BK ; IS KING
CMP SQUARE ; IN CHECK?
BNE RETJ ; SET INCHEK=0
LDA #$00 ; IF IT IS
STA INCHEK
RETJ RTS
;
; IF A PIECE HAS BEEN CAPTURED BY
; A TRIAL MOVE, GENERATE REPLIES &
; EVALUATE THE EXCHANGE GAIN/LOSS
;
TREE BVC RETJ ; NO CAP
LDY #$07 ; (PIECES)
LDA SQUARE
LOOPX CMP BK,Y
BEQ FOUNX
DEY
BEQ RETJ ; (KING)
BPL LOOPX ; SAVE
FOUNX LDA POINTS,Y ; BEST CAP
CMP BCAP0,X ; AT THIS
BCC NOMAX ; LEVEL
STA BCAP0,X
NOMAX DEC STATE
LDA #$FB ; IF STATE=FB
CMP STATE ; TIME TO TURN
BEQ UPTREE ; AROUND
JSR GENRM ; GENERATE FURTHER
UPTREE INC STATE ; CAPTURES
RTS
;
; THE PLAYER'S MOVE IS INPUT
;
INPUT CMP #$08 ; NOT A LEGAL
BCS ERROR ; SQUARE #
JSR DISMV
DISP LDX #$1F
SEARCH LDA BOARD,X
CMP DIS2
BEQ HERE ; DISPLAY
DEX ; PIECE AT
BPL SEARCH ; FROM
HERE STX DIS1 ; SQUARE
STX PIECE
ERROR JMP CHESS
;
; GENERATE ALL MOVES FOR ONE
; SIDE, CALL JANUS AFTER EACH
; ONE FOR NEXT STE?
;
;
<snip>
;
; end of file
It is scary that I can understand most of that without having touched it for 20 plus years.
07-13-2006, 01:56 PM
6502 Machine Language
Linear Mode
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