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[pdp8.git] / sw / adventure / src / SEED.RA

	FIELD1	SETIDL\r
/IDLE RANDOM NUMBER GENERATOR\r
	EXTERN	#IDLE\r
\r
	JA	#RET\r
	TEXT	+SETIDL+\r
SXR,	SETX	XR\r
	SETB	BP\r
BP,	F 0.0\r
XR,	ORG	.+3\r
EXP,	0\r
IDLAD,	ADDR	#IDLE-1		/ Pointer to idle routine in FRTS\r
POINT,\r
JOB,	ADDR	DOIT		/ Address of routine to run\r
	ORG	XR+10\r
K0100,	100\r
K0003,	3\r
ROTWRD, 0017\r
	#LBL=.\r
	COMMON	NUMCOM\r
NUMBER,	ORG	.+3\r
\r
	COMMON	TXTCOM\r
RTEXT,	ORG	.+1147\r
LINES,	ORG	.+0044\r
ASCVAR,	ORG	.+0003\r
TXTLOC,	ORG	.+0003\r
DATA,	ORG	.+0352\r
	ORG	#LBL\r
SEEDPT,	ADDR	NUMBER\r
	0\r
DATHAK,	7777\r
	ADDR	ASCVAR\r
DATABL,	1763-1		/ Address of Direct Access table entry 8 in FRTS\r
COUNT,	0		/ Idle loop count\r
COUNT2,	7774		/ Outer counter\r
RESET,	7774		/ Outer counter value\r
X4=14			/ Autoindex reg\r
	ORG	10*3+BP\r
	FNOP\r
	JA	SXR\r
	0\r
RET,	JA	.\r
\r
	BASE	0\r
#RET,	STARTD\r
	FLDA	10*3\r
	FSTA	RET\r
	SETB	BP\r
	BASE	BP\r
	STARTF\r
	TRAP4	SET8	/GO TO 8 MODE STUFF.\r
	JA	RET	/DONE. ON IDLE QUEUE.\r
\r
SET8,	0\r
/\r
/ Horrible hackery. This sets up the FRTS direct access table\r
/ to allow us to open the ADVENT.DA file without having to\r
/ rebuild it each time. Open it using USR, and this lets us\r
/ go use it later. (DEFINE FILE always creates a new one.)\r
	TAD	DATABL\r
	DCAZ	X4\r
SCDF,	CDF	0\r
	TAD	DATHAK\r
	DCA%	X4\r
	TAD	DATHAK+1\r
	DCA%	X4\r
	TAD	DATHAK+2\r
	DCA%	X4\r
	TAD	CDFIDL\r
	SZA CLA\r
	JMP	SFIELD	/ALREADY DONE\r
	TAD	IDLAD	/FIELD OF IDLE ROUTINE\r
	JMS	MKCDF\r
	DCA	CDFIDL\r
	TAD	IDLAD+1	/ADDRESS OF #IDLE\r
	DCAZ	X4\r
CDFIDL,	0		/GETS CDF\r
	TAD	SKPINS	/SKP INSTRUCTION\r
	DCAZ%	X4	/STORE AT #IDLE\r
	TAD	JOB+1	/ADDRESS OF IDLE ROUTINE\r
	DCAZ%	X4	/STORE AT #IDLE+1\r
	TAD	JOB\r
	JMS	MKCDF\r
	IAC		/ CDF -> CIF CDF\r
	DCAZ%	X4	/STORE AT #IDLE+2\r
SFIELD,	CIF CDF\r
	JMP%	SET8\r
\r
/\r
/ Blinky lights\r
/\r
SKPINS,\r
DOIT,	SKP		/ Entry point, one-time use constant\r
	TAD	ROTWRD	/GET WORD TO DISPLAY\r
STALL,	ISZ	COUNT\r
	JMP	STALL\r
	ISZ	COUNT2\r
	JMP	STALL\r
FLOP,	RAL		/Shift over\r
	DCA	ROTWRD	/Save it\r
	TAD	RESET	/Reset outer counter\r
	DCA	COUNT2\r
	SNL\r
	JMP	DONE\r
	TAD	ROTWRD\r
FLIP,	RAR		/Rotate back\r
	DCA	ROTWRD\r
	TAD	FLOP\r
	DCA	COUNT	/Save old rotate\r
	TAD	FLIP	/And flip 'em around\r
	DCA	FLOP\r
	TAD	COUNT\r
	DCA	FLIP\r
	DCA	COUNT\r
DONE,	TAD	SEEDPT\r
	JMS	MKCDF\r
	DCA	.+1\r
	0\r
	TAD	SEEDPT+1\r
	DCA	EXP\r
	CLL IAC\r
	TAD	EXP\r
	DCA	POINT\r
	TAD%	POINT\r
	TAD	K0100\r
	SPA\r
	JMP	OVRFLO\r
	DCA%	POINT\r
	JMP	DOIT+1\r
\r
OVRFLO,	CLA CLL\r
	DCA%	POINT\r
	TAD%	EXP\r
	IAC\r
	AND	K0003\r
	DCA%	EXP\r
	JMP	DOIT+1\r
/ Change field number into CDF instruction\r
MKCDF,	0\r
	CLL RTL\r
	RAL		/INTO BITS 6-8\r
	TAD	SCDF	/CDF TO #IDLE\r
	JMP%	MKCDF\r
\r
	END\r