Initial commit.

atari/warm.src

@@ -0,0 +1,131 @@
+	PAGE
+	SBTTL "--- WARMSTART ROUTINE ---"
+
+	; -------------
+	; ZIP WARMSTART
+	; -------------
+
+WARM1:	LDA	#0		; CLEAR ALL Z-PAGE VARIABLES
+	LDX	#ZEROPG
+ST0:	STA	0,X
+	INX
+;	CPX	#ZPGTOP		; NOT NEEDED FOR ATARI
+	BNE	ST0
+
+	; INIT THE PAGING TABLE
+
+	TAX			; = 0
+	LDA	#$FF
+ST1:	STA	PTABL,X
+	STA	PTABH,X
+	INX
+	BNE	ST1
+
+	; CLEAR THE TIMESTAMP MAP
+
+	TXA			; = 0
+ST2:	STA	LRUMAP,X
+	INX
+	BNE	ST2
+
+	INC	ZSP		; INIT Z-STACK POINTERS
+	INC	OLDZSP		; TO "1"
+	INC	STAMP		; INIT TIMESTAMP
+
+	; GRAB THE FIRST BLOCK OF PRELOAD
+
+	LDA	#HIGH ZBEGIN	; MSB OF PRELOAD START ADDRESS
+	STA	ZCODE		; FREEZE IT HERE
+	STA	DBUFF+HI	; LSB IS ALWAYS ZERO
+	DEC	ZPURE		; (ATARI ONLY) FORCE FETCH FROM PRELOAD
+	JSR	GETDSK		; [DBLOCK] SET TO Z-BLOCK 0
+
+	; EXTRACT GAME DATA FROM Z-CODE HEADER
+
+	LDX	ZBEGIN+ZENDLD	; MSB OF ENDLOAD POINTER
+	INX			; ADD 1 TO GET
+	STX	ZPURE		; 1ST "PURE" PAGE OF Z-CODE
+
+	TXA			; ADD START PAGE OF PRELOAD
+	CLC			; TO CALC ABSOLUTE START ADDRESS
+	ADC	ZCODE		; OF PAGING SPACE
+	STA	PAGE0
+
+	JSR	MEMTOP		; RETURNS TOP RAM PAGE IN [A]
+	SEC
+	SBC	PAGE0		; SUBTRACT ADDRESS OF PAGING SPACE
+	BEQ	NORAM
+	BCS	SETNP		; ERROR IF NOT ENOUGH RAM
+
+	; *** ERROR #0 -- INSUFFICIENT RAM ***
+
+NORAM:	LDA	#0
+	JMP	ZERROR
+
+SETNP:	STA	PMAX		; SET # SWAPPING PAGES
+
+	LDA	ZBEGIN+ZMODE
+	ORA	#%00100000	; ENABLE SPLIT-SCREEN
+	STA	ZBEGIN+ZMODE
+
+	AND	#%00000010	; ISOLATE STATUS-FORMAT BIT
+	STA	TIMEFL		; 0=SCORE, NZ=TIME
+
+	LDA	ZBEGIN+ZGLOBA	; GET MSB OF GLOBAL TABLE ADDR
+	CLC			; CONVERT TO
+	ADC	ZCODE		; ABSOLUTE ADDRESS
+	STA	GLOBAL+HI
+	LDA	ZBEGIN+ZGLOBA+1	; LSB NEEDN'T CHANGE
+	STA	GLOBAL+LO
+
+	LDA	ZBEGIN+ZFWORD	; DO SAME FOR FWORDS TABLE
+	CLC
+	ADC	ZCODE
+	STA	FWORDS+HI
+	LDA	ZBEGIN+ZFWORD+1	; NO CHANGE FOR LSB
+	STA	FWORDS+LO
+
+	LDA	ZBEGIN+ZVOCAB	; NOW DO VOCABULARY TABLE
+	CLC
+	ADC	ZCODE
+	STA	VOCAB+HI
+	LDA	ZBEGIN+ZVOCAB+1	; LSB SAME
+	STA	VOCAB+LO
+
+	LDA	ZBEGIN+ZOBJEC	; NOT TO MENTION
+	CLC			; THE OBJECT TABLE
+	ADC	ZCODE
+	STA	OBJTAB+HI
+	LDA	ZBEGIN+ZOBJEC+1	; LSB SAME
+	STA	OBJTAB+LO
+
+	; FETCH THE REST OF THE PRELOAD
+
+LDPRE:	LDA	DBLOCK+LO	; CHECK CURRENT BLOCK #
+	CMP	ZPURE		; LOADED LAST PRELOAD PAGE YET?
+	BCS	WARMEX		; YES, TIME TO PLAY!
+	JSR	GETDSK		; ELSE GRAB NEXT Z-BLOCK
+	JMP	LDPRE
+
+WARMEX:	LDA	ZBEGIN+ZGO	; GET START ADDRESS OF Z-CODE
+	STA	ZPCM		; MSB
+	LDA	ZBEGIN+ZGO+1	; AND LSB
+	STA	ZPCL		; HIGH BIT ALREADY ZEROED
+
+	LDA	#21
+	STA	LMAX		; PREVENT WEIRDNESS
+
+	JSR	SIDE2		; REQUEST SIDE 2 OF DISK
+	JSR	CLS		; CLEAR SCREEN
+
+	LDA	#$FF
+	STA	SCRIPT		; ENABLE SCRIPTING
+
+	LDA	ZBEGIN+ZSCRIP+1	; SET SCRIPT FLAG
+	ORA	SFLAG		; TO PREVIOUS SETTING
+	STA	ZBEGIN+ZSCRIP+1 ; (BM 5/14/85)
+
+	; ... AND FALL INTO MAIN LOOP
+
+	END
+