*20
/LINC-8 SIMULATOR TRAP PROCESSOR, DEC-12-SI1B.
/
/COPYRIGHT 1969, DIGITAL EQUIPMENT CORP.
/MAYNARD, MASS.
/
/D. LANGBEIN, 27 MAY 1969
/REVISED 21 JULY 1969
/REVISED 8 AUGUST 1969
/
/OPERATION DEFINITIONS FOR LINC MODE ASSEMBLY
/OF PDP-8 MODE IOT INSTRUCIONS
KCCA=6032
KRSA=6034
KRBA=6036
TSFA=6041
TLSA=6046
RMFA=6244
/
/SOME LINC-8 DEFINITIONS
OPR=500
KBD=515
/
*20
	JMP	ST20	/BECOMES JMP INIT
	LDF	3
	LIF	2
	DJR
	JMP	20	/GO TO 20 IN SEGMENT 2
			/(04020)
/
/400 RESTART
RST400,	JMP	ST400	/BECOMES JMP INIT
	LDF	3
	LIF	2
	DJR
	HLT
	JMP	400	/GO TO 400 IN SEGMENT 2
			/(04400)
/
/START GUIDE
GUIDE,	JMP	INIT
	LDF	2
	RDC		/READ GUIDE START BLOCK
	7400		/INTO QUARTER 3,SEGMENT 2
	LDF	3
	LIF	2
	JMP	1400	/START GUIDE
/
/ERROR STOP
*130
ERR,	HLT		/UNIDENTIFIED INSTRUCTION
	JMP	RET	/IN AC AT HLT. RETURNS TO
			/USER W AC CLEARED WHEN
			/CONTINUE PRESSED.
/
/MISC CONSTANTS
*134
PC,	0		/ADDRESS OF TRAPPED
			/INSTRUCTION
M70,	70
ONE,	1
/
/TRAP ENTRY AND MACHINE STATE SAVING
*141
	STC	AC	/SAVE AC
	ROL  I	1	/SAVE LINK
	STC	LC
	QAC		/GET H O 11 Q REG BITS
	ROL	1
	QLZ		/GET L O BIT
	ADD	ONE
	STC	Q	/SAVE IT
	ADD ONE
	FLO		/GET OVERFLOW BIT IF ON
	CLR
	STC	OVL	/SAVE IT.0=OFF. 1=ON
	SET	17	/SAVE LOCATION 0
	0
/
/INSTRUCTION IDENTIFICATION.
	PDP
	PMODE
FETCH,	RIB		/READ INTERRUPT BUFFER
	AND	M70	/GET INSTRUCTION FIELD
	TAD	CDFX	/MAKE IT INTO A CDF N
	DCA	.+1
	7402		/BECOMES CDF N
	STA		/SET AC TO -1
	TAD	140	/COMPUTE ADDRESS OF
	DCA	PC	/TRAPPED INSTRUCTION
	TAD  I	PC	/OBTAIN INSTRUCTION
			/CAUSING TRAP
CDFX,	CDF		/SET DATA FIELDB/BMBJBJCSCOCRCRCYB,B CTCHCEB CCCOCNCTCECNCTB COCFB CRCECGB