/ vim: set sw=8 noexpandtab :

*000

INTRET,	0
	JMP GOTINT

*010

HEAD,	7777		/ because preincrement
TAIL,	7777

*100

TTBUSY,	0

*200

	CLA IAC
	KIE
	ION
LOOP,	CLA
	TAD TTBUSY
	SZA
	JMP LOOP
	TAD TAIL
	CMA IAC
	TAD HEAD
	SNA
	JMP LOOP
	CLA
	CDF 0010
	TAD I TAIL
	CDF 0000
	IOF		/ critical section
	TPC
	CLA IAC
	ION
	DCA TTBUSY	/ end critical section
	JMP LOOP

*400

GOTINT,	DCA SAVEA
	GTF
	AND (7577)
	DCA SAVEF
	TSF
	JMP KBIN
	DCA TTBUSY
	TCF
KBIN,	KSF
	JMP RETINT
	KRB
	CDF 0010
	DCA I HEAD
	CDF 0000
RETINT,	CLA
	TAD SAVEF
	RTF
	CLA
	TAD SAVEA
	ION
	JMP I INTRET

SAVEA,	0
SAVEF,	0