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SYSTEM.X68
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SYSTEM.X68
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; =============================================================================
; SYSTEM MANAGEMENT (SYSTEM CODE)
; =============================================================================
; -----------------------------------------------------------------------------
SYSINIT
; INITIALIZES THE SYSTEM
; INPUT - NONE
; OUTPUT - NONE
; MODIFIES - NONE
; -----------------------------------------------------------------------------
MOVE.L (A7)+,A0 ; GET RETURN ADDRESS
JSR KBDINIT ; INIT KEYBOARD
JSR SCRINIT ; INIT SCREEN
JSR DMMINIT ; INIT DYNAMIC MEMORY
ANDI.W #$DFFF,SR ; SWITCH TO USER
MOVE.L A0,-(A7) ; PUT RETURN ADDRESS
RTS
; =============================================================================
; SCREEN MANAGEMENT (SYSTEM CODE)
; =============================================================================
; -----------------------------------------------------------------------------
SCRINIT
; INITIALIZES THE SCREEN, SCREEN-RELATED INTERRUPT AND VARS.
; INPUT - NONE
; OUTPUT - NONE
; MODIFIES - D0,D1,D2,D3
; -----------------------------------------------------------------------------
; TO DO:
; - DISABLE INTS (SET INT BITS IN SR TO 111)
MOVE.W SR,D0
OR.W #$0700,D0
MOVE.W D0,SR
; - DISABLE ALL AUTO-IRQ (SEE TRAP #15 TASK 32)
* MOVE.B #32,D0
* MOVE.B #6,D1
* CLR.B D2
* TRAP #15
; - INSTALL SCRUPD INTO TRAP SCRTRAP
MOVE.L #SCRUPD,($80+SCRTRAP*4)
; - SET RESOLUTION TO SCRWIDTH X SCRHEIGHT
MOVEQ #33,D0
MOVE.L #SCRWIDTH<<16+SCRHEIGH,D1
TRAP #15
; - SET WINDOWED MODE
MOVE.L #1,D1
TRAP #15
; - CLEAR VISIBLE BUFFER
MOVEQ #94,D0
TRAP #15
; - ENABLE DOUBLE BUFFER
MOVEQ #92,D0
MOVE.B #17,D1
TRAP #15
; - CLEAR HIDDEN BUFFER
MOVEQ #11,D0
MOVE.W $FF00,D1
TRAP #15
; - INSTALL SCRISR FOR IRQ SCRIRQ (IRQ INTERRUPT VECTOR BEGINS
; AT $60. INSTALLATION IS SIMILAR TO TRAP INSTALLATION)
MOVE.L #SCRISR,($60+SCRIRQ*4)
; - ENABLE AUTO-IRQ EVERY SCRTIM MS FOR IRQ SCRIRQ (SEE TRAP #15
; TASK 32)
MOVEQ #32,D0
MOVE.B #6,D1
MOVE.L #SCRIRQ,D2
OR.B #$80,D2
MOVE.L #SCRTIM,D3
TRAP #15
; - CLEAR SCRINTCT AND SCRCYCCT
CLR.B (SCRINTCT)
CLR.B (SCRCYCCT)
; - ENABLE INTS (SET INT BITS IN SR TO 000)
MOVE.W SR,D0
AND.W #$F8FF,D0
MOVE.W D0,SR
RTS
; -----------------------------------------------------------------------------
SCRISR
; SCREEN TIMER ISR. INCREASES THE INTERRUPT COUNTER AND UPDATES DOUBLE BUFFER.
; INPUT - NONE
; OUTPUT - NONE
; MODIFIES - NONE
; -----------------------------------------------------------------------------
ADDQ.B #1,(SCRINTCT) ; UPDATE INT FLAG/COUNTER
ADDQ.B #1,(SCRCYCCT) ; UPDATE CYCLE COUNTER
RTE
; -----------------------------------------------------------------------------
SCRUPD
; TRAP SERVICE ROUTINE IN CHARGE OF VISUALIZING CURRENT FRAME AND CLEARING
; BUFFER FOR THE NEXT ONE.
; INPUT - NONE
; OUTPUT - NONE
; MODIFIES - NONE
; -----------------------------------------------------------------------------
; TO DO: UPDATE DOUBLE BUFFER AND CLEAR HIDDEN BUFFER
MOVEM.L D0-D1,-(A7)
MOVEQ #94,D0
TRAP #15
MOVEQ #11,D0
MOVE.W #$FF00,D1
TRAP #15
MOVEM.L (A7)+,D0-D1
RTE
; =============================================================================
; KEYBOARD MANAGEMENT (SYSTEM CODE)
; =============================================================================
; -----------------------------------------------------------------------------
KBDINIT
; INITIALIZES THE SYSTEM VARIABLES KBDSYS AND KBDVAL
; INPUT - NONE
; OUTPUT - NONE
; MODIFIES - NONE
; -----------------------------------------------------------------------------
CLR.B (KBDVAL) ; INIT VARS
CLR.B (KBDEDGE)
MOVE.L #KBDREAD,($80+KBDTRAP*4) ; INSTALL
RTS
; -----------------------------------------------------------------------------
KBDREAD
; TRAP SERVICE ROUTINE.
; UPDATES THE SYSTEM VARIABLES KBDEDGE AND KBDVAL ACCORDING TO THE BITFIELD
; DESCRIBED IN SYSCONST. KBDVAL HOLDS THE CURRENT VALUES AND KBDEDGE HOLDS
; RISING EDGES FROM PREVIOUS CALL TO THE CURRENT ONE.
; INPUT - NONE
; OUTPUT - (KBDVAL) AND (KBDEDGE)
; MODIFIES - NONE
; -----------------------------------------------------------------------------
; TO DO: UPDATE KBDVAL AND KBDEDGE
MOVEM.L D0-D3,-(A7)
MOVE.B (KBDVAL),D3
;PUT IN D2 THE VALUES OF KEYS: ARROW LEFT, UP, RIGHT AND DOWN
MOVEQ #19,D0
MOVE.L #KBDLEFT<<24+KBDUP<<16+KBDRIGHT<<8+KBDDOWN,D1
TRAP #15
MOVE.L D1,D2
;PUT IN D1 THE VALUES OF KEYS: FIRE1, FIRE2, FIRE3 AND PAUSE
MOVE.L #KBDFIRE1<<24+KBDFIRE2<<16+KBDFIRE3<<8+KBDPAUSE,D1
TRAP #15
;SET D3 WITH KEYS PRESSED AND NOT PRESSED
BTST.L #24,D2
BNE .KBDLEFT
ANDI.B #%11111110,D3
BRA .COND1
.KBDLEFT ;LEFT ARROW PRESSED
ORI.B #KBDMSKLF,D3
.COND1
BTST.L #16,D2
BNE .KBDUP
ANDI.B #%11111101,D3
BRA .COND2
.KBDUP ;UP ARROW PRESSED
ORI.B #KBDMSKUP,D3
.COND2
BTST.L #8,D2
BNE .KBDRT
ANDI.B #%11111011,D3
BRA .COND3
.KBDRT ;RIGHT ARROW PRESSED
ORI.B #KBDMSKRT,D3
.COND3
BTST.L #0,D2
BNE .KBDDOWN
ANDI.B #%11110111,D3
BRA .COND4
.KBDDOWN ;DOWN ARROW PRESSED
ORI.B #KBDMSKDN,D3
.COND4
BTST.L #24,D1
BNE .KBDF1
ANDI.B #%11101111,D3
BRA .COND5
.KBDF1 ;FIRE1 PRESSED
ORI.B #KBDMSKF1,D3
.COND5
BTST.L #16,D1
BNE .KBDF2
ANDI.B #%11011111,D3
BRA .COND6
.KBDF2 ;FIRE2 PRESSED
ORI.B #KBDMSKF2,D3
.COND6
BTST.L #8,D1
BNE .KBDF3
ANDI.B #%10111111,D3
BRA .COND7
.KBDF3 ;FIRE3 PRESSED
ORI.B #KBDMSKF3,D3
.COND7
BTST.L #0,D1
BNE .KBDP
ANDI.B #%01111111,D3
BRA .FINISH
.KBDP ;PAUSE PRESSED
ORI.B #KBDMSKPS,D3
.FINISH ;PUT D3 IN (KBDVAL) AND SET (KBDEDGE)
MOVE.B (KBDVAL),D1
MOVE.B D3,(KBDVAL)
NOT.B D1
AND.B D1,D3
MOVE.B D3,(KBDEDGE)
MOVEM.L (A7)+,D0-D3
RTE
; =============================================================================
; DYNAMIC MEMORY MANAGEMENT (SYSTEM CODE)
; DYNAMIC MEMORY IS A SET OF DMMBNUM SLOTS OF DMMBSIZE BYTES EACH ONE.
; DMMBSIZE MUST BE POWER OF TWO. A SLOT HAS:
; - HEADER - 1 WORD. SPECIFIES THE OWNER (0 MEANS OWNED BY SYSTEM)
; - DATA - DMMBSIZE - 2 BYTES. MAY CONTAIN VARS AND ANY KIND OF DATA RELATED
; THE THE OWNER. IF OWNER==0, DATA IS MEANINGLESS.
; =============================================================================
; -----------------------------------------------------------------------------
DMMINIT
; INITIALIZES THE DYNAMIC MEMORY TO ALL OWNED BY SYSTEM.
; INPUT - NONE
; OUTPUT - NONE
; MODIFIES - NONE
; -----------------------------------------------------------------------------
MOVEM.L D0/A0,-(A7)
LEA DMMDATA,A0
MOVE.W #DMMBNUM-1,D0
.LOOP MOVE.W #DMMSYSID,(A0)
ADD.L #DMMBSIZE,A0
DBRA.W D0,.LOOP
MOVEM.L (A7)+,D0/A0
RTS
; -----------------------------------------------------------------------------
DMMFIRST
; SEARCHES THE FIRST MEMORY SLOT NOT OWNED BY SYSTEM AND OUTPUTS A POINTER
; TO THE CORRESPONDING DATA (SLOT ADDRESS+2)
; INPUT - NONE
; OUTPUT - A0 : POINTER TO THE DATA OR 0 IF NOT FOUND
; MODIFIES - NONE (ASIDE OF OUTPUT)
; -----------------------------------------------------------------------------
LEA DMMDATA,A0
DMMFRLOP TST.W (A0)+
BNE DMMFRFND
ADD.L #DMMBSIZE-2,A0
DMMFRCOM CMP.L #DMMDATA+DMMBSIZE*DMMBNUM-1,A0
BLT DMMFRLOP
MOVE.L #0,A0
DMMFRFND RTS
; -----------------------------------------------------------------------------
DMMNEXT
; SEARCHES THE NEXT MEMORY SLOT NOT OWNED BY SYSTEM AND OUTPUTS A POINTER
; TO THE CORRESPONDING DATA (SLOT ADDRESS+2)
; INPUT - A0 : POINTER WITHIN THE CURRENT SLOT
; OUTPUT - A0 : POINTER TO THE DATA OR 0 IF NOT FOUND
; MODIFIES - NONE (ASIDE OF OUTPUT)
; -----------------------------------------------------------------------------
MOVE.L D0,-(A7)
MOVE.L A0,D0
AND.L #-DMMBSIZE,D0 ; TAKE ADVANTAGE OF ALIGNMENT
ADD.L #DMMBSIZE,D0
MOVE.L D0,A0
MOVE.L (A7)+,D0
BRA DMMFRCOM
; -----------------------------------------------------------------------------
DMMFRSTO
; SEARCHES THE FIRST MEMORY SLOT WITH THE SPECIFIED ID AND OUTPUTS A POINTER
; TO THE CORRESPONDING DATA (SLOT ADDRESS+2)
; INPUT - D0.W : ID TO SEARCH
; OUTPUT - A0 : POINTER TO THE DATA OR 0 IF NOT FOUND
; MODIFIES - NONE (ASIDE OF OUTPUT)
; -----------------------------------------------------------------------------
LEA DMMDATA,A0
DMMFLOOP CMP.W (A0)+,D0
BEQ DMMFFND
ADD.L #DMMBSIZE-2,A0
DMMFCOM CMP.L #DMMDATA+DMMBSIZE*DMMBNUM-1,A0
BLT DMMFLOOP
MOVE.L #0,A0
DMMFFND RTS
; -----------------------------------------------------------------------------
DMMNEXTO
; SEARCHES THE NEXT MEMORY SLOT WITH THE SPECIFIED ID AND OUTPUTS A POINTER
; TO THE CORRESPONDING DATA (SLOT ADDRESS+2)
; INPUT - D0.W : ID TO SEARCH
; A0 : POINTER WITHIN THE CURRENT SLOT
; OUTPUT - A0 : POINTER TO THE DATA OR 0 IF NOT FOUND
; MODIFIES - NONE (ASIDE OF OUTPUT)
; -----------------------------------------------------------------------------
MOVE.L D0,-(A7)
MOVE.L A0,D0
AND.L #-DMMBSIZE,D0 ; TAKE ADVANTAGE OF ALIGNMENT
ADD.L #DMMBSIZE,D0
MOVE.L D0,A0
MOVE.L (A7)+,D0
BRA DMMFCOM
; -----------------------------------------------------------------------------
DMMALLOC
; SEARCHES THE FIRST FREE (SYS OWNED) SLOT, ASSIGNS TO THE SPECIFIED OWNER
; AND RETURNS A POINTER TO THE CORRESPONDING DATA (SLOT ADDRESS + 2)
; INPUT - D0.W : ID TO ASSIGN
; OUTPUT - A0 : POINTER TO THE DATA OR 0 IF NOT FREE SPACE
; MODIFIES - NONE (ASIDE OF OUTPUT)
; -----------------------------------------------------------------------------
MOVE.W D0,-(A7)
CLR.W D0
JSR DMMFRSTO
MOVE.W (A7)+,D0
CMP.L #0,A0
BEQ .END
MOVE.W D0,-2(A0)
.END RTS
; -----------------------------------------------------------------------------
DMMFREE
; FREES THE SLOT TO WHICH THE PROVIDED POINTER BELONGS BY SETTING ITS OWNED TO
; SYSTEM (0)
; INPUT - A0 : POINTER BELONGING TO THE SLOT TO FREE
; OUTPUT - NONE
; MODIFIES - NONE
; -----------------------------------------------------------------------------
MOVEM.L D0/A0,-(A7)
MOVE.L A0,D0
AND.L #-DMMBSIZE,D0 ; TAKE ADVANTAGE OF ALIGNMENT
MOVE.L D0,A0
CLR.W (A0)
MOVEM.L (A7)+,D0/A0
RTS
*~Font name~Courier New~
*~Font size~10~
*~Tab type~0~
*~Tab size~4~