/ LIVING PDP8

/ CONWAY'S GAME OF LIFE


/---------------------------------------------------------------------
/ CONFIGURATION PARAMETERS


/ SIZE OF THE PLAYING FIELD
/ MAX COLUMNS=64(DEC)=100(OCT)
/ MAX ROWS==64(DEC)=100(OCT)
	ROWS=10
	COLS=10

/ HAS THE FIELD LIMITS OR IS IT ENDLESS?
	
	LIMITS=1

/ BORDER BEHAVIOUR FOR LIMITED FIELD
/ 0 - OFF FIELD POSITIONS ARE ASSUMED TO BE ALWAYS DEAD
/ 1 - OFF FIELD POSITIONS ARE ASSUMED TO BE ALWAYS ALIFE
	
	BORDER=0

/---------------------------------------------------------------------
/ TEST PROGRAM
	*200
	TAD	DD
	JMS	XCALC
	HLT
DD,	30

/---------------------------------------------------------------------
/ DATA HOLDING AND ACCESS

/ DATA IS HELD IN AN ARRAY OF WORDS, ASSIGNING ONE BIT PER POSITION.
/ POSITION ADDRESS IS PASSED IN AC WHILE CALLING ACCESS ROUTINES.

	PAGE		/ START ON NEW PAGE

GET,	0		/ GET POSITION'S VALUE
	DCA	ADR	/ SAVE ADDRESS
	JMS	LIMIT	/ TEST LIMIT
	JMP I	GET	/ ERROR RETURN, RETURN WITH LIMIT VALUE IN AC
	JMS	POSCAL	/ CALC WORD ADDRESS AND BIT POSITION
	

SET,	0		/ SET POSITION'S VALUE TO 1
CLEAR,	0		/ CLEAR POSITION'S VALUE TO 0

LIMIT,	0
	TAD	ADR
	BSW		/ NOW ROW ADDRESS IN LOWER BITS
	AND	K77	/ MASK OUT UPPER BITS
	TAD	KNMROW
	SMA
	JMP	LGD1	/ ONE LIMIT GOOD
	CLA
	TAD	BORDER	/ BORDER STANDARD RETURN VALUE
	JMP I	LIMIT	/ ERROR RETURN
LGD1,	CLA CLL
	TAD	ADR
	AND	K77
	TAD	KNMCO
	SMA
	JMP	LGD2
	CLA CLL
	TAD	BORDER
	JMP I	LIMIT	/ ERROR RETURN
LGD2,	ISZ	LIMIT	/ PREPARE GOOD RETURN
	JMP I	LIMIT	/ GOOD RETURN

ADR,	0		/ TEMPORARY ADDRESS STORAGE
K77,	77
KNMCO,	1-COLS
KNMROW,	1-ROWS

/---------------------------------------------------------------------
/ CALCULATE BIT POSITION FOR X VALUE.
/ RESULTS IN FOLLOWING LOCATIONS:
/ XW: WORD ADDRESS OF DESIRED POSITION
/ XB: BIT ADDRESS OF DESIRED  POSITION

/ POSITION IN AC, HIGHEST SUPPORTED NUMBER IS 95!

POSCAL,	0
	DCA	XBIT
	DCA	XWORD

	TAD	KN48
	JMS	MTEST

	TAD	KN24
	JMS	MTEST
	HLT
	TAD	KN12
	JMS	MTEST

	TAD	XWORD	/ SHIFT BACK RESULT
	RAR	
	DCA	XWORD
	
	JMP I	POSCAL	/ RETURN TO CALLER

MTEST,	0
	TAD	XBIT
	SMA		
	SKP
	JMP	IGN12
	DCA	XBIT
	ISZ	XWORD
IGN12,	CLA CLL
	TAD	XWORD
	RAL
	DCA	XWORD	
	JMP I	MTEST
			
KN48,	-60
KN24,	-30
KN12,	-14
	
	*1000
XWORD,	0		/ INTEGER DIVISION RESULT
XBIT,	0		/ INTIGER DIVISION'S REST

/---------------------------------------------------------------------
/ THIS IS IT, FOLKS!
$