diff --git a/mach/pdp/libem/Makefile b/mach/pdp/libem/Makefile
new file mode 100644
index 000000000..7bc76fc01
--- /dev/null
+++ b/mach/pdp/libem/Makefile
@@ -0,0 +1,39 @@
+l=../lib
+
+install:	cp
+
+cp:             all
+		cp head_em $l/head_em
+		cp tail_em $l/tail_em
+		rm -f head_em tail_em
+
+cmp:            all
+		cmp head_em $l/head_em
+		cmp tail_em $l/tail_em
+		rm -f head_em tail_em
+
+all:            head_em tail_em
+
+head_em:        head_em.s
+		pdp -c head_em.s ; mv head_em.o head_em
+
+tail_em:        tail_em.s.a
+		mkdir tmp; \
+		cd tmp; \
+		ar x ../tail_em.s.a; \
+		for i in *.s; \
+		do \
+		  pdp -c $$i; \
+		done; \
+		ar cr tail.a `lorder *.o | tsort`; \
+		cp tail.a ../tail_em; \
+		cd ..; \
+		rm -r tmp
+
+clean:
+		-rm -f `ar t tail_em.s.a` ; rm -rf temp ; rm -f *.o
+opr:
+		make pr | opr
+pr:
+		@pr `pwd`/Makefile `pwd`/head_em.s
+		@ar pv tail_em.s.a | pr -h `pwd`/tail_em.s.a
diff --git a/mach/pdp/libem/RT.s b/mach/pdp/libem/RT.s
new file mode 100644
index 000000000..c6e14d3ca
--- /dev/null
+++ b/mach/pdp/libem/RT.s
@@ -0,0 +1,10 @@
+	.globl RT,RTr2,RTr2r4
+
+RTr2r4:
+	mov (sp)+,r4
+RTr2:
+	mov (sp)+,r2
+RT:
+	mov r5,sp
+	mov (sp)+,r5
+	rts pc
diff --git a/mach/pdp/libem/aar.s b/mach/pdp/libem/aar.s
new file mode 100644
index 000000000..5b98774dc
--- /dev/null
+++ b/mach/pdp/libem/aar.s
@@ -0,0 +1,12 @@
+.text
+.globl aar~
+
+/r0 : description address
+/r1 : element number
+/base address is on stack
+aar~:
+	sub	(r0),r1
+	mov	04(r0),r0
+	mul	r0,r1
+	add	r1,02(sp)
+	rts	pc
diff --git a/mach/pdp/libem/adf.s b/mach/pdp/libem/adf.s
new file mode 100644
index 000000000..b3bfc9166
--- /dev/null
+++ b/mach/pdp/libem/adf.s
@@ -0,0 +1,13 @@
+.text
+.globl adf~
+.globl setfloat~
+
+/size in r0
+adf~:
+	mov	(sp)+,r1
+	jsr	pc,setfloat~
+	movf	(sp)+,r0
+	addf	(sp)+,r0
+	movf	r0,-(sp)
+	setl
+	jmp	(r1)
diff --git a/mach/pdp/libem/adi.s b/mach/pdp/libem/adi.s
new file mode 100644
index 000000000..8f896d7f6
--- /dev/null
+++ b/mach/pdp/libem/adi.s
@@ -0,0 +1,19 @@
+.text
+.globl adi~
+.globl unknown~
+
+/size in r0
+adi~:
+	mov	(sp)+,r1
+	cmp	r0,$04
+	bgt	1f
+	cmp	r0,$02
+	bgt	2f
+	add	(sp)+,(sp)
+	jmp	(r1)
+2:	add	(sp)+,02(sp)
+	add	(sp)+,02(sp)
+	adc	(sp)
+	jmp	(r1)
+1:
+	jmp	unknown~
diff --git a/mach/pdp/libem/and.s b/mach/pdp/libem/and.s
new file mode 100644
index 000000000..76d6596ff
--- /dev/null
+++ b/mach/pdp/libem/and.s
@@ -0,0 +1,13 @@
+.text
+.globl and~
+.globl save1~
+
+and~:
+	mov	(sp)+,save1~
+	mov	sp,r1
+	add	r0,r1
+	asr	r0
+1:	com	(sp)
+	bic	(sp)+,(r1)+
+	sob	r0,1b
+	jmp	*save1~
diff --git a/mach/pdp/libem/blm.s b/mach/pdp/libem/blm.s
new file mode 100644
index 000000000..73f47585b
--- /dev/null
+++ b/mach/pdp/libem/blm.s
@@ -0,0 +1,28 @@
+.globl blm~
+.globl save~,retu~
+
+/ Size in r0
+blm~:
+	jsr	pc,save~
+	mov	(sp)+,r2
+	mov	(sp)+,r3
+	mov	r0,r1
+	asr	r0
+	beq	2f
+/ Now avoid wrong copy.
+/ The pieces may overlap !
+	cmp	r3,r2
+	beq	2f
+	blt	3f
+1:
+	mov	(r3)+,(r2)+
+	sob	r0,1b
+2:
+	jmp	retu~
+3:
+	add	r1,r3
+	add	r1,r2
+4:
+	mov	-(r3),-(r2)
+	sob	r0,4b
+	br	2b
diff --git a/mach/pdp/libem/cff.s b/mach/pdp/libem/cff.s
new file mode 100644
index 000000000..c8c6c59df
--- /dev/null
+++ b/mach/pdp/libem/cff.s
@@ -0,0 +1,14 @@
+.text
+.globl cff~
+.globl setfloat~
+
+cff~:
+	mov	(sp)+,r1
+	mov	(sp)+,r0
+	cmp	(sp)+,r0
+	beq	1f
+	jsr	pc,setfloat~
+	movof	(sp)+,r0
+	movf	r0,-(sp)
+	setl
+1:	jmp	(r1)
diff --git a/mach/pdp/libem/cfi.s b/mach/pdp/libem/cfi.s
new file mode 100644
index 000000000..8dbb51317
--- /dev/null
+++ b/mach/pdp/libem/cfi.s
@@ -0,0 +1,14 @@
+.text
+.globl cfi~
+.globl setfloat~,setint~
+
+cfi~:
+	mov	(sp)+,r1
+	mov	(sp)+,r0
+	jsr	pc,setint~
+	mov	(sp)+,r0
+	jsr	pc,setfloat~
+	movf	(sp)+,r0
+	movfi	r0,-(sp)
+	setl;seti
+	jmp	(r1)
diff --git a/mach/pdp/libem/cif.s b/mach/pdp/libem/cif.s
new file mode 100644
index 000000000..e7bf0dd34
--- /dev/null
+++ b/mach/pdp/libem/cif.s
@@ -0,0 +1,24 @@
+.text
+.globl cif~,cuf~
+.globl setint~,setfloat~
+
+cif~:
+	mov	(sp)+,r1
+	mov	(sp)+,r0
+	jsr	pc,setfloat~
+	mov	(sp)+,r0
+1:	jsr	pc,setint~
+	movif	(sp)+,r0
+	movf	r0,-(sp)
+	setl;seti
+	jmp	(r1)
+cuf~:
+	mov	(sp)+,r1
+	mov	(sp)+,r0
+	jsr	pc,setfloat~
+	mov	(sp)+,r0
+	cmp	r0,$02
+	bne	1b
+	clr	-(sp)
+	mov	$04,r0
+	br	1b
diff --git a/mach/pdp/libem/cii.s b/mach/pdp/libem/cii.s
new file mode 100644
index 000000000..fb442f722
--- /dev/null
+++ b/mach/pdp/libem/cii.s
@@ -0,0 +1,23 @@
+.text
+.globl cii~
+.globl save1~
+
+/convert int to int
+/ 1 byte -> ? : sign extension
+cii~:
+	mov	(sp)+,save1~
+	mov	(sp)+,r0
+	sub	(sp)+,r0
+	ble	1f
+	asr	r0
+	bcc	2f
+	movb	(sp),r1
+	mov	r1,(sp)
+2:	tst	r0
+	beq	3f
+	tst	(sp)
+4:	sxt	-(sp)
+	sob	r0,4b
+3:	jmp	*save1~
+1:	sub	r0,sp
+	jmp	*save1~
diff --git a/mach/pdp/libem/ciu.s b/mach/pdp/libem/ciu.s
new file mode 100644
index 000000000..6ce2ee0a3
--- /dev/null
+++ b/mach/pdp/libem/ciu.s
@@ -0,0 +1,13 @@
+.text
+.globl cuu~
+cuu~:
+	mov	(sp)+,r1
+	mov	(sp)+,r0
+	sub	(sp)+,r0
+	ble	1f
+	asr	r0
+2:	clr	-(sp)
+	sob	r0,2b
+	jmp	(r1)
+1:	sub	r0,sp
+	jmp	(r1)
diff --git a/mach/pdp/libem/cmf.s b/mach/pdp/libem/cmf.s
new file mode 100644
index 000000000..abe6c956e
--- /dev/null
+++ b/mach/pdp/libem/cmf.s
@@ -0,0 +1,19 @@
+.text
+.globl cmf~
+.globl setfloat~
+
+cmf~:
+	jsr	pc,setfloat~
+	mov	(sp)+,r1
+	movf	(sp)+,r0
+	movf	(sp)+,r1
+	clr	r0
+	cmpf	r0,r1
+	setl
+	cfcc
+	beq	1f
+	blt	2f
+	dec	r0
+	jmp	(r1)
+2:	inc	r0
+1:	jmp	(r1)
diff --git a/mach/pdp/libem/cmi.s b/mach/pdp/libem/cmi.s
new file mode 100644
index 000000000..c17775c3b
--- /dev/null
+++ b/mach/pdp/libem/cmi.s
@@ -0,0 +1,17 @@
+.text
+.globl cmi~
+.globl cmi4~,unknown~
+
+/ Size in r0
+cmi~:
+	cmp	r0,$02
+	bne	1f
+	mov	(sp)+,r1
+	mov	(sp)+,r0
+	sub	(sp)+,r0
+	neg	r0
+	jmp	(r1)
+1:	cmp	r0,$04
+	bne	2f
+	jmp	cmi4~
+2:	jmp	unknown~
diff --git a/mach/pdp/libem/cmi4.s b/mach/pdp/libem/cmi4.s
new file mode 100644
index 000000000..6aec66bfa
--- /dev/null
+++ b/mach/pdp/libem/cmi4.s
@@ -0,0 +1,21 @@
+.text
+.globl cmi4~
+.globl save1~
+
+cmi4~:
+	mov	(sp)+,r1
+	clr	r0
+	cmp	(sp),4(sp)
+	bgt	1f
+	blt	2f
+	cmp	2(sp),6(sp)
+	bhi	1f
+	beq	3f
+2:
+	inc	r0
+	br	3f
+1:
+	dec	r0
+3:
+	add	$10,sp
+	jmp	(r1)
diff --git a/mach/pdp/libem/cms.s b/mach/pdp/libem/cms.s
new file mode 100644
index 000000000..9d7fedd8f
--- /dev/null
+++ b/mach/pdp/libem/cms.s
@@ -0,0 +1,16 @@
+.text
+.globl cms~
+.globl save~,retu~
+
+cms~:
+	jsr	pc,save~
+	mov	r0,r2
+	add	sp,r2
+	mov	r2,r4
+	add	r0,r4
+	asr	r0
+2:	cmp	(sp)+,(r2)+
+	bne	1f
+	sob	r0,2b
+1:	mov	r4,sp
+	jmp	retu~
diff --git a/mach/pdp/libem/cmu.s b/mach/pdp/libem/cmu.s
new file mode 100644
index 000000000..11ccc459b
--- /dev/null
+++ b/mach/pdp/libem/cmu.s
@@ -0,0 +1,22 @@
+.text
+.globl cmu~
+.globl unknown~,cmu4~
+
+cmu~:
+	cmp	r0,$02
+	bne	3f
+	mov	(sp)+,r1
+	clr	r0
+	cmp	(sp)+,(sp)+
+	beq	2f
+	bhi	1f
+	inc	r0
+	br	2f
+1:
+	dec	r0
+2:
+	jmp	(r1)
+3:	cmp	r0,$04
+	bne	2f
+	jmp	cmu4~
+2:	jmp	unknown~
diff --git a/mach/pdp/libem/cmu4.s b/mach/pdp/libem/cmu4.s
new file mode 100644
index 000000000..e81f03861
--- /dev/null
+++ b/mach/pdp/libem/cmu4.s
@@ -0,0 +1,20 @@
+	.text
+	.globl	cmu4~
+	.globl	save~,retu~
+cmu4~:
+	mov	(sp)+,r1
+	clr	r0
+	cmp	(sp),4(sp)
+	bhi	1f
+	blo	2f
+	cmp	2(sp),6(sp)
+	bhi	1f
+	beq	3f
+2:
+	inc	r0
+	br	3f
+1:
+	dec	r0
+3:
+	add	$10,sp
+	jmp	(r1)
diff --git a/mach/pdp/libem/csa.s b/mach/pdp/libem/csa.s
new file mode 100644
index 000000000..46fb2d650
--- /dev/null
+++ b/mach/pdp/libem/csa.s
@@ -0,0 +1,21 @@
+.text
+.globl csa~
+.globl fat~
+
+ECASE	= 20.
+
+csa~:
+	sub	02(r0),r1
+	blt	1f
+	cmp	04(r0),r1
+	blo	1f
+	asl	r1
+	add	r1,r0
+	mov	06(r0),r1
+	beq	2f
+	jmp	(r1)
+1:	mov	(r0),r0
+	beq	2f
+	jmp	(r0)
+2:	mov	$ECASE,-(sp)
+	jmp	fat~
diff --git a/mach/pdp/libem/csb.s b/mach/pdp/libem/csb.s
new file mode 100644
index 000000000..2feba2d88
--- /dev/null
+++ b/mach/pdp/libem/csb.s
@@ -0,0 +1,25 @@
+.text
+.globl csb~
+.globl fat~
+
+ECASE	= 20.
+
+csb~:
+	mov	r3,-(sp)
+	mov	(r0)+,-(sp)
+	mov	(r0)+,r3
+	beq	1f
+3:	cmp	(r0)+,r1
+	beq	2f
+	tst	(r0)+
+	sob	r3,3b
+1:	mov	(sp)+,r1
+	br	4f
+2:	tst	(sp)+
+	mov	(r0),r1
+4:	beq	5f
+	mov	(sp)+,r3
+	jmp	(r1)
+5:	mov	(sp)+,r3
+	mov	$ECASE,-(sp)
+	jmp	fat~
diff --git a/mach/pdp/libem/dup.s b/mach/pdp/libem/dup.s
new file mode 100644
index 000000000..a47ebc71b
--- /dev/null
+++ b/mach/pdp/libem/dup.s
@@ -0,0 +1,12 @@
+.text
+.globl dup~
+.globl save1~
+
+dup~:
+	mov	(sp)+,save1~
+	mov	sp,r1
+	add	r0,r1
+	asr	r0
+1:	mov	-(r1),-(sp)
+	sob	r0,1b
+	jmp	*save1~
diff --git a/mach/pdp/libem/dvf.s b/mach/pdp/libem/dvf.s
new file mode 100644
index 000000000..db8b9e1a1
--- /dev/null
+++ b/mach/pdp/libem/dvf.s
@@ -0,0 +1,13 @@
+.text
+.globl dvf~
+.globl setfloat~
+
+dvf~:
+	mov	(sp)+,r1
+	jsr	pc,setfloat~
+	movf	(sp)+,r0
+	movf	(sp)+,r1
+	divf	r0,r1
+	movf	r1,-(sp)
+	setl
+	jmp	(r1)
diff --git a/mach/pdp/libem/dvi.s b/mach/pdp/libem/dvi.s
new file mode 100644
index 000000000..f50b93924
--- /dev/null
+++ b/mach/pdp/libem/dvi.s
@@ -0,0 +1,19 @@
+.text
+.globl dvi~
+.globl save1~,unknown~,dvi4~
+
+dvi~:
+	mov	(sp)+,save1~
+	cmp	r0,$04
+	bgt	1f
+	beq	2f
+	mov	02(sp),r1
+	sxt	r0
+	div	(sp)+,r0
+	mov	r0,(sp)
+	br	3f
+2:	jsr	pc,dvi4~
+	mov	r1,-(sp)
+	mov	r0,-(sp)
+3:	jmp	*save1~
+1:	jmp	unknown~
diff --git a/mach/pdp/libem/dvi4.s b/mach/pdp/libem/dvi4.s
new file mode 100644
index 000000000..0708330a2
--- /dev/null
+++ b/mach/pdp/libem/dvi4.s
@@ -0,0 +1,81 @@
+.text
+.globl dvi4~
+.globl save~,retu~
+
+dvi4~:
+	jsr	pc,save~
+	mov	02(sp),r3
+	sxt	r4
+	bpl	1f
+	neg	r3
+1:	cmp	r4,(sp)
+	bne	hardldiv
+	mov	06(sp),r2
+	mov	04(sp),r1
+	bge	2f
+	neg	r1
+	neg	r2
+	sbc	r1
+	com	r4
+2:	mov	r4,-(sp)
+	clr	r0
+	div	r3,r0
+	mov	r0,-(sp)
+	mov	r1,r0
+	mov	r1,r4
+	mov	r2,r1
+	div	r3,r0
+	bvc	3f
+	mov	r2,r1
+	mov	r4,r0
+	sub	r3,r0
+	div	r3,r0
+	tst	r1
+	sxt	r1
+	add	r1,r0
+3:	mov	r0,r1
+	mov	(sp)+,r0
+	br	4f
+hardldiv:
+	clr	-(sp)
+	mov	010(sp),r2
+	mov	06(sp),r1
+	bpl	5f
+	com	(sp)
+	neg	r1
+	neg	r2
+	sbc	r1
+5:	clr	r0
+	mov	02(sp),r3
+	bge	6f
+	neg	r3
+	neg	04(sp)
+	sbc	r3
+	com	(sp)
+6:	mov	$16.,r4
+9:	clc
+	rol	r2
+	rol	r1
+	rol	r0
+	cmp	r3,r0
+	bhi	7f
+	bcs	8f
+	cmp	04(sp),r1
+	blos	8f
+7:	sob	r4,9b
+	br	1f
+8:	sub	04(sp),r1
+	sbc	r0
+	sub	r3,r0
+	inc	r2
+	sob	r4,9b
+1:
+	mov	r2,r1
+	clr	r0
+4:	tst	(sp)+
+	beq	1f
+	neg	r0
+	neg	r1
+	sbc	r0
+1:	add	$010,sp
+	jmp	retu~
diff --git a/mach/pdp/libem/dvu.s b/mach/pdp/libem/dvu.s
new file mode 100644
index 000000000..d70910c49
--- /dev/null
+++ b/mach/pdp/libem/dvu.s
@@ -0,0 +1,17 @@
+.text
+.globl dvu~
+.globl save1~,unknown~,dvu4~,dvu2~
+
+dvu~:
+	mov	(sp)+,save1~
+	cmp	r0,$04
+	bgt	1f
+	beq	2f
+	jsr	pc,dvu2~
+	mov	r0,-(sp)
+	br	3f
+2:	jsr	pc,dvu4~
+	mov	r1,-(sp)
+	mov	r0,-(sp)
+3:	jmp	*save1~
+1:	jmp	unknown~
diff --git a/mach/pdp/libem/dvu2.s b/mach/pdp/libem/dvu2.s
new file mode 100644
index 000000000..2107c0365
--- /dev/null
+++ b/mach/pdp/libem/dvu2.s
@@ -0,0 +1,15 @@
+.text
+.globl dvu2~
+dvu2~:
+	clr	r0
+	mov	04(sp),r1
+	tst	02(sp)
+	blt	1f
+	div	02(sp),r0
+2:	mov	(sp)+,r1
+	add	$04,sp
+	jmp	(r1)
+1:	cmp	02(sp),r1
+	bhi	2b
+	inc	r0
+	br	2b
diff --git a/mach/pdp/libem/dvu4.s b/mach/pdp/libem/dvu4.s
new file mode 100644
index 000000000..974f1e083
--- /dev/null
+++ b/mach/pdp/libem/dvu4.s
@@ -0,0 +1,61 @@
+.text
+.globl dvu4~
+.globl save~,retu~
+
+dvu4~:
+	jsr	pc,save~
+	clr	r0
+	tst	(sp)
+	bne	harddvu4
+	tst	02(sp)
+	blt	harddvu4
+	mov	06(sp),r2
+	mov	04(sp),r1
+	mov	02(sp),r3
+	div	r3,r0
+	mov	r0,-(sp)
+	mov	r1,r0
+	mov	r1,r4
+	mov	r2,r1
+	div	r3,r0
+	bvc	1f
+	mov	r2,r1
+	mov	r4,r0
+	sub	r3,r0
+	div	r3,r0
+	tst	r1
+	sxt	r1
+	add	r1,r0
+1:	mov	r0,r1
+	mov	(sp)+,r0
+	br	2f
+harddvu4:
+	mov	06(sp),r2
+	mov	04(sp),r1
+	mov	(sp),r3
+	mov	$17.,r4
+	br	3f
+6:	rol	r2
+	rol	r1
+	rol	r0
+3:	cmp	r3,r0
+	bhi	4f
+	blo	5f
+	cmp	02(sp),r1
+	blos	5f
+4:	clc
+	sob	r4,6b
+	br	7f
+5:	sub	02(sp),r1
+	sbc	r0
+	sub	r3,r0
+	sec
+	sob	r4,6b
+7:	rol	r2
+	bcc	8f
+	mov	$01,r0
+	br	9f
+8:	clr	r0
+9:	mov	r2,r1
+2:	add	$010,sp
+	jmp	retu~
diff --git a/mach/pdp/libem/eret.s b/mach/pdp/libem/eret.s
new file mode 100644
index 000000000..cce078fa4
--- /dev/null
+++ b/mach/pdp/libem/eret.s
@@ -0,0 +1,8 @@
+	.globl eret
+
+eret:
+	mov r5,sp
+	mov (sp)+,r5
+	mov (sp)+,r4
+	mov (sp)+,r2
+	rts pc
diff --git a/mach/pdp/libem/exg.s b/mach/pdp/libem/exg.s
new file mode 100644
index 000000000..7b5119382
--- /dev/null
+++ b/mach/pdp/libem/exg.s
@@ -0,0 +1,18 @@
+	.text
+	.globl exg~
+exg~:	jsr pc,save~
+	mov sp,r4
+	sub r0,sp
+	mov sp,r3
+	mov r0,r1
+1:
+	mov (r4)+,(r3)+
+	sob r0,1b
+	asr r1
+	mov sp,r4
+1:
+	mov (r4)+,(r3)+
+	sob r1,1b
+	mov r4,sp
+	jmp retu~
+
diff --git a/mach/pdp/libem/fef.s b/mach/pdp/libem/fef.s
new file mode 100644
index 000000000..bd4b56a04
--- /dev/null
+++ b/mach/pdp/libem/fef.s
@@ -0,0 +1,13 @@
+.text
+.globl fef~
+.globl setfloat~
+
+fef~:
+	mov	(sp)+,r1
+	jsr	pc,setfloat~
+	movf	(sp),r0
+	movei	r0,-(sp)
+	movie	$0,r0
+	movf	r0,02(sp)
+	setl
+	jmp	(r1)
diff --git a/mach/pdp/libem/fif.s b/mach/pdp/libem/fif.s
new file mode 100644
index 000000000..7382cfabe
--- /dev/null
+++ b/mach/pdp/libem/fif.s
@@ -0,0 +1,13 @@
+.text
+.globl fif~
+.globl setfloat~
+
+fif~:
+	mov	(sp)+,r1
+	jsr	pc,setfloat~
+	movf	(sp)+,r0
+	modf	(sp)+,r0
+	movf	r0,-(sp)
+	movf	r1,-(sp)
+	setl
+	jmp	(r1)
diff --git a/mach/pdp/libem/gto.s b/mach/pdp/libem/gto.s
new file mode 100644
index 000000000..845ae9232
--- /dev/null
+++ b/mach/pdp/libem/gto.s
@@ -0,0 +1,17 @@
+.text
+.globl gto~
+
+gto~:
+;	mov     (sp)+,r4
+;	mov     4(r4),r5
+;	mov     2(r4),sp
+;	jmp     *(r4)
+
+	mov	(sp)+,r3
+1:	cmp	4(r3),r5
+	jeq	2f
+	mov	2(r5),r4
+	mov	4(r5),r2
+	br	1b
+2:	mov	2(r3),sp
+	jmp	*(r3)
diff --git a/mach/pdp/libem/head_em.s b/mach/pdp/libem/head_em.s
new file mode 100644
index 000000000..de7fba87e
--- /dev/null
+++ b/mach/pdp/libem/head_em.s
@@ -0,0 +1,75 @@
+	.globl  LINO_AD,FILN_AD
+	.globl  ERANGE,ESET,EHEAP,EILLINS,ECASE
+	.globl  hol0,trppc~,trpim~,reghp~
+
+rti     = 2
+stst    = 170300 ^ tst
+
+.float  = 1             / this should be parameterized somehow
+.hardfp = 1             / only relevant if .float on
+
+LINO_AD = 0.
+FILN_AD = 4.
+
+ERANGE  = 1.
+ESET    = 2.
+EFOVFL  = 4.
+EFUNFL  = 5.
+EFDIVZ  = 7.
+EFUND   = 9.
+ECONV   = 10.
+EHEAP   = 17.
+EILLINS = 18.
+ECASE   = 20.
+
+.if .float
+/       .globl  fltused;        fltused:
+.if 1 - .hardfp
+/	sys     48.;4.;fptrap	/ if not commented it will appear as undefined
+.endif
+	sys     48.;8.;sig8
+	ldfps   $7600
+.endif
+	mov     2(sp),r0
+	clr     -2(r0)
+	mov     sp,r0
+	sub     $4,sp
+	mov     4(sp),(sp)
+	tst     (r0)+
+	mov     r0,2(sp)
+1:
+	tst     (r0)+
+	bne     1b
+	cmp     r0,*2(sp)
+	blo     1f
+	tst     -(r0)
+1:
+	mov     r0,4(sp)
+	jsr     pc,_m_a_i_n
+/ next two lines for as long as tail needs printf
+/	mov     r0,-(sp)
+/	jsr     pc,*$_exit
+	sys     1.
+
+	.data
+hol0:   0;0     / line no
+	0;0     / file
+trppc~: 0
+trpim~: 0
+reghp~: _end
+
+	.text
+sig8:
+.if .float
+	mov     r0,-(sp)
+	stst    r0
+	mov     1f(r0),-(sp)
+	jsr     pc,trp~
+	sys     48.;8.;sig8
+	mov     (sp)+,r0
+	rti
+
+	.data
+1:      EILLINS; EILLINS; EFDIVZ; ECONV; EFOVFL; EFUNFL; EFUND; EILLINS
+	.text
+.endif
diff --git a/mach/pdp/libem/hlt.s b/mach/pdp/libem/hlt.s
new file mode 100644
index 000000000..799feaedc
--- /dev/null
+++ b/mach/pdp/libem/hlt.s
@@ -0,0 +1,10 @@
+.text
+.globl hlt~
+
+exit	= 1
+
+hlt~:
+	mov	(sp)+,r0
+	bne	1f
+	sys	exit
+1:	4
diff --git a/mach/pdp/libem/iaar.s b/mach/pdp/libem/iaar.s
new file mode 100644
index 000000000..317d91745
--- /dev/null
+++ b/mach/pdp/libem/iaar.s
@@ -0,0 +1,18 @@
+.text
+.globl iaar~
+.globl aar~,trp~
+
+EILLINS = 18.
+
+iaar~:
+	mov	(sp)+,r0
+	cmp	(sp)+,$02
+	bne	1f
+	mov	02(sp),r1
+	mov	r0,02(sp)
+	mov	(sp)+,r0
+	jmp	aar~
+1:	mov	$EILLINS,-(sp)
+	jsr	pc,trp~
+	add	$06,sp
+	jmp	(r0)
diff --git a/mach/pdp/libem/ilar.s b/mach/pdp/libem/ilar.s
new file mode 100644
index 000000000..0b36a8778
--- /dev/null
+++ b/mach/pdp/libem/ilar.s
@@ -0,0 +1,18 @@
+.text
+.globl ilar~
+.globl lar~,trp~
+
+EILLINS = 18.
+
+ilar~:
+	mov	(sp)+,r0
+	cmp	(sp)+,$02
+	bne	1f
+	mov	02(sp),r1
+	mov	r0,02(sp)
+	mov	(sp)+,r0
+	jmp	lar~
+1:	mov	$EILLINS,-(sp)
+	jsr	pc,trp~
+	add	$06,sp
+	jmp	(r0)
diff --git a/mach/pdp/libem/inn.s b/mach/pdp/libem/inn.s
new file mode 100644
index 000000000..fdd1cd677
--- /dev/null
+++ b/mach/pdp/libem/inn.s
@@ -0,0 +1,22 @@
+.text
+.globl inn~
+
+inn~:
+	mov	r0,-(sp)
+	clr	r0
+	div	$010,r0
+	cmp	r0,(sp)
+	bcc	1f
+	add	sp,r0
+	add	$4,r0
+	bitb	bits(r1),(r0)
+	beq	1f
+	mov	$01,r0
+	br	2f
+1:	clr	r0
+2:	mov	02(sp),r1
+	add	(sp)+,sp
+	tst	(sp)+
+	jmp	(r1)
+.data
+bits:	.byte	1,2,4,10,20,40,100,200
diff --git a/mach/pdp/libem/isar.s b/mach/pdp/libem/isar.s
new file mode 100644
index 000000000..5a3c1863c
--- /dev/null
+++ b/mach/pdp/libem/isar.s
@@ -0,0 +1,18 @@
+.text
+.globl isar~
+.globl sar~,trp~
+
+EILLINS = 18.
+
+isar~:
+	mov	(sp)+,r0
+	cmp	(sp)+,$02
+	bne	1f
+	mov	02(sp),r1
+	mov	r0,02(sp)
+	mov	(sp)+,r0
+	jmp	sar~
+1:	mov	$EILLINS,-(sp)
+	jsr	pc,trp~
+	add	$06,sp
+	jmp	(r0)
diff --git a/mach/pdp/libem/lar.s b/mach/pdp/libem/lar.s
new file mode 100644
index 000000000..d242f21d7
--- /dev/null
+++ b/mach/pdp/libem/lar.s
@@ -0,0 +1,20 @@
+.text
+.globl lar~
+.globl save1~
+
+lar~:
+	mov	(sp)+,save1~
+	sub	(r0),r1
+	mov	04(r0),r0
+	mul	r0,r1
+	add	(sp)+,r1
+	add	r0,r1
+	asr	r0
+	beq	1f
+2:	mov	-(r1),-(sp)
+	sob	r0,2b
+	jmp	*save1~
+1:	clr	r0
+	bisb	-(r1),r0
+	mov	r0,-(sp)
+	jmp	*save1~
diff --git a/mach/pdp/libem/los2.s b/mach/pdp/libem/los2.s
new file mode 100644
index 000000000..e270e7d09
--- /dev/null
+++ b/mach/pdp/libem/los2.s
@@ -0,0 +1,16 @@
+.text
+.globl los2~
+.globl save1~
+
+los2~:
+	mov	(sp)+,save1~
+	cmp	r0,$01
+	bne	1f
+	clr	-(sp)
+	bisb	(r1),(sp)
+	jmp	*save1~
+1:	add	r0,r1
+	asr	r0
+2:	mov	-(r1),-(sp)
+	sob	r0,2b
+	jmp	*save1~
diff --git a/mach/pdp/libem/mlf.s b/mach/pdp/libem/mlf.s
new file mode 100644
index 000000000..b5b355a30
--- /dev/null
+++ b/mach/pdp/libem/mlf.s
@@ -0,0 +1,12 @@
+.text
+.globl mlf~
+.globl setfloat~
+
+mlf~:
+	mov	(sp)+,r1
+	jsr	pc,setfloat~
+	movf	(sp)+,r0
+	mulf	(sp)+,r0
+	movf	r0,-(sp)
+	setl
+	jmp	(r1)
diff --git a/mach/pdp/libem/mli.s b/mach/pdp/libem/mli.s
new file mode 100644
index 000000000..80399e941
--- /dev/null
+++ b/mach/pdp/libem/mli.s
@@ -0,0 +1,19 @@
+.text
+.globl mli~
+.globl save1~,unknown~,mli4~
+
+mli~:
+	cmp	r0,$04
+	bgt	1f
+	beq	2f
+	mov	(sp)+,r0
+	mov	(sp)+,r1
+	mul	(sp)+,r1
+	mov	r1,-(sp)
+	jmp	(r0)
+2:	mov	(sp)+,save1~
+	jsr	pc,mli4~
+	mov	r1,-(sp)
+	mov	r0,-(sp)
+	jmp	*save1~
+1:	jmp	unknown~
diff --git a/mach/pdp/libem/mli4.s b/mach/pdp/libem/mli4.s
new file mode 100644
index 000000000..b8f0d0798
--- /dev/null
+++ b/mach/pdp/libem/mli4.s
@@ -0,0 +1,19 @@
+.text
+.globl mli4~
+.globl save~,retu~
+
+mli4~:
+	jsr	pc,save~
+	mov	02(sp),r2
+	sxt	r1
+	sub	(sp),r1
+	mov	06(sp),r0
+	sxt	r3
+	sub	04(sp),r3
+	mul	r0,r1
+	mul	r2,r3
+	add	r1,r3
+	mul	r2,r0
+	sub	r3,r0
+	add	$010,sp
+	jmp	retu~
diff --git a/mach/pdp/libem/mlu.s b/mach/pdp/libem/mlu.s
new file mode 100644
index 000000000..8bd5c9188
--- /dev/null
+++ b/mach/pdp/libem/mlu.s
@@ -0,0 +1,19 @@
+.text
+.globl mlu~
+.globl save1~,unknown~,mlu4~
+
+mlu~:
+	cmp	r0,$04
+	bgt	1f
+	beq	2f
+	mov	(sp)+,r0
+	mov	(sp)+,r1
+	mul	(sp)+,r1
+	mov	r1,-(sp)
+	jmp	(r0)
+2:	mov	(sp)+,save1~
+	jsr	pc,mlu4~
+	mov	r1,-(sp)
+	mov	r0,-(sp)
+	jmp	*save1~
+1:	jmp	unknown~
diff --git a/mach/pdp/libem/mlu4.s b/mach/pdp/libem/mlu4.s
new file mode 100644
index 000000000..46f8c2358
--- /dev/null
+++ b/mach/pdp/libem/mlu4.s
@@ -0,0 +1,23 @@
+.text
+.globl mlu4~
+.globl save~,retu~
+
+mlu4~:
+	jsr	pc,save~
+	clr	r0
+	mov	02(sp),r1
+	mov	06(sp),r3
+	mul	r3,r0
+	tst	r3
+	bge	1f
+	ashc	$15.,r0
+1:	mov	02(sp),r3
+	clr	r2
+	mul	04(sp),r2
+	add	r3,r0
+	mov	06(sp),r3
+	clr	r2
+	mul	(sp),r2
+	add	r3,r0
+	add	$010,sp
+	jmp	retu~
diff --git a/mach/pdp/libem/mon.s b/mach/pdp/libem/mon.s
new file mode 100644
index 000000000..a4a61adb0
--- /dev/null
+++ b/mach/pdp/libem/mon.s
@@ -0,0 +1,145 @@
+.text
+.globl mon~
+.globl sigtrp~,save~,retu~,save1~
+
+indir	= 0
+fork	= 2
+getpid	= 20.
+sigtrp	= 48.
+EBADMON = 25.
+
+HBMASK	= 0177400
+REG01M	= 030
+REG1M	= 020
+ERRMASK	= 040
+
+/ Associated with every monitor call is a descriptor.
+/ The low order three bits describe how values are returned,
+/ the next two bits specify if arguments are expected in
+/ r0 and/or r1, the next bit is not used, and the next
+/ three bits specify the number of arguments disregarding
+/ arguments in registers.
+
+mon~:
+	cmp	02(sp),$sigtrp
+	bne	1f
+	jmp	sigtrp~
+1:	jsr	pc,save~
+	mov	(sp)+,r4
+	mov	r4,r2
+	asl	r4
+	mov	args(r4),r3
+	mov	r3,r4
+	bit	$ERRMASK,r4
+	bne	err
+	cmp	r2,$fork
+	bne	2f
+	jbr	fork~
+2:	bic	$HBMASK,r2
+	bis	$sys,r2
+	mov	r2,9f
+	bit	$REG01M,r3
+	beq	1f
+	mov	(sp)+,r0
+	bit	$REG1M,r3
+	beq	1f
+	mov	(sp)+,r1
+1:	ash	$-6,r3
+	beq	2f
+	mov	$[9f+2],r2
+1:	mov	(sp)+,(r2)+
+	sob	r3,1b
+2:	sys	indir ; 9f
+	bcs	2f
+	clr	r3
+4:	asr	r4
+	bcc	1f
+	mov	r0,-(sp)
+1:	asr	r4
+	bcc	1f
+	mov	r1,-(sp)
+1:	asr	r4
+	bcc	1f
+	clr	-(sp)
+1:	jmp	retu~
+2:	mov	r0,-(sp)
+	mov	r0,-(sp)
+	jmp	retu~
+fork~:
+	sys	fork
+	br	1f
+	bcs	2b
+	clr	r1
+	br	4b
+1:	mov	$1,r1
+	br	4b
+err:
+	mov	$EBADMON,-(sp)
+	jsr	pc,trp~
+	tst	(sp)+
+	jmp	retu~
+.data
+.even
+9: .=.+12.
+args:	ERRMASK	/ 0 : error
+	010	/ 1 : exit(st); ---
+	07	/ 2 : fork(); e10
+	0215	/ 3 : read(addr,nb,fild); e-0
+	0215	/ 4 : write(addr,nb,fild); e-0
+	0205	/ 5 : open(str,flag); e-0
+	014	/ 6 : close(fild); e--
+	07	/ 7 : wait(); e10
+	0205	/ 8 : creat(str,mode); e-0
+	0204	/ 9 : link(str1,str2); e--
+	0104	/10 : unlink(str); e--
+	ERRMASK	/11 : error
+	0104	/12 : chdir(str); e--
+	03	/13 : time(); -10
+	0304	/14 : mknod(str,mode,addr); e--
+	0204	/15 : chmod(str,mode); e--
+	0304	/16 : chown(str,owner,grp); e--
+	ERRMASK	/17 : error
+	0204	/18 : stat(str,buf); e--
+	0217	/19 : lseek(high,low,fild); e10
+	01	/20 : getpid(); --0
+	0304	/21 : mount(str1,str2,fl); e--
+	0104	/22 : umount(str); e--
+	014	/23 : setuid(uid); e--
+	03	/24 : getuid(); -01
+	024	/25 : stime(high,low); e--
+	0315	/26 : ptrace(pid,addr,req,d); e-0
+	011	/27 : alarm(sec); --0
+	0114	/28 : fstat(buf,fild); e--
+	0	/29 : pause(); ---
+	0204	/30 : utime(str,timep); e--
+	ERRMASK	/31 : error
+	ERRMASK	/32 : error
+	0204	/33 : access(str,mode): e--
+	010	/34 : nice(incr); ---
+	0100	/35 : ftime(bufp); ---
+	0	/36 : sync(); ---
+	0114	/37 : kill(sig,pid); e--
+	ERRMASK	/38 : error
+	ERRMASK	/39 : error
+	ERRMASK	/40 : error
+	025	/41 : dup(fild,newfild); e-0
+	07	/42 : pipe(); e10
+	0100	/43 : times(buf); ---
+	0400	/44 : profil(buff,siz,off,sc); ---
+	ERRMASK	/45 : error
+	014	/46 : setgid(gid); e--
+	03	/47 : getgid(); -01
+	0	/48 : sigtrp(trap,sig); e-0; SPECIAL TREATMENT
+	ERRMASK	/49 : error
+	ERRMASK	/50 : error
+	0104	/51 : acct(file); e--
+	0304	/52 : phys(seg,siz,phaddr); e--
+	0104	/53 : lock(flag); e--
+	0304	/54 : ioctl(fild,req,argp); e--
+	ERRMASK	/55 : error
+	0204	/56 : mpxcall(cmd,vec); e--
+	ERRMASK	/57 : error
+	ERRMASK	/58 : error
+	0304	/59 : exece(name,argv,envp); e--
+	0104	/60 : umask(complmode); e--
+	0104	/61 : chroot(str); e--
diff --git a/mach/pdp/libem/ngf.s b/mach/pdp/libem/ngf.s
new file mode 100644
index 000000000..64c1d2fe3
--- /dev/null
+++ b/mach/pdp/libem/ngf.s
@@ -0,0 +1,10 @@
+.text
+.globl ngf~
+.globl setfloat~
+
+ngf~:
+	mov	(sp)+,r1
+	jsr	pc,setfloat~
+	negf	(sp)
+	setl
+	jmp	(r1)
diff --git a/mach/pdp/libem/ngi.s b/mach/pdp/libem/ngi.s
new file mode 100644
index 000000000..db248cbab
--- /dev/null
+++ b/mach/pdp/libem/ngi.s
@@ -0,0 +1,17 @@
+.text
+.globl ngi~
+.globl unknown~
+
+ngi~:
+	mov	(sp)+,r1
+	cmp	r0,$02
+	bgt	1f
+	neg	(sp)
+	jmp	(r1)
+1:	cmp	r0,$04
+	bgt	2f
+	neg	(sp)
+	neg	02(sp)
+	sbc	(sp)
+	jmp	(r1)
+2:	jmp	unknown~
diff --git a/mach/pdp/libem/nop.s b/mach/pdp/libem/nop.s
new file mode 100644
index 000000000..bb11d432d
--- /dev/null
+++ b/mach/pdp/libem/nop.s
@@ -0,0 +1,12 @@
+.text
+.globl nop~
+.globl hol0,prf~
+
+nop~:
+	mov	hol0,-(sp)
+	mov	$fmt,-(sp)
+	jsr	pc,prf~
+	add	$04,sp
+	rts	pc
+.data
+fmt:	<test %d\n\0>
diff --git a/mach/pdp/libem/prf.s b/mach/pdp/libem/prf.s
new file mode 100644
index 000000000..d93b8c6f5
--- /dev/null
+++ b/mach/pdp/libem/prf.s
@@ -0,0 +1,33 @@
+.text
+.globl prf~
+.globl save~,retu~,hol0,_printf
+
+prf~:
+	jsr	pc,save~
+	mov	hol0,-(sp)
+	mov	hol0+4,r0
+	beq	1f
+	mov	r0,r2
+	mov	$40.,r1
+3:	movb	(r2)+,r3
+	beq	2f
+	cmpb	r3,$0177
+	bge	1f
+	cmpb	r3,$040
+	blt	1f
+	sob	r1,3b
+	clrb	(r2)
+2:	mov	sp,r1
+	mov	r1,-(sp)
+	mov	r0,-(sp)
+	mov	$fmt,-(sp)
+	jsr	pc,_printf
+	add	$010,sp
+	jsr	pc,_printf
+	jmp	retu~
+1:	mov	$name,r0
+	br	2b
+
+.data
+fmt:	<"%s", sp = %d, line %d: \0>
+name:	<_unknown file_\0>
diff --git a/mach/pdp/libem/printf.s b/mach/pdp/libem/printf.s
new file mode 100644
index 000000000..f690ae1e8
--- /dev/null
+++ b/mach/pdp/libem/printf.s
@@ -0,0 +1,62 @@
+.text
+.globl _printf
+
+write	= 4
+
+_printf:
+	mov	r2,-(sp)
+	mov	r3,-(sp)
+	mov	r4,-(sp)
+	mov	sp,r3
+	mov	$buff,r4
+	add	$010,r3
+	mov	(r3)+,r2
+prloop:
+	movb	(r2)+,r0
+	beq	ready
+	cmpb	r0,$045
+	bne	1f
+	movb	(r2)+,r0
+	cmpb	r0,$0144
+	beq	2f
+	cmpb	r0,$0163
+	beq	3f
+1:	movb	r0,(r4)+
+	br	prloop
+2:	mov	(r3)+,r1
+	bge	4f
+	movb	$055,(r4)+
+	neg	r1
+4:	jsr	pc,printn
+	br	prloop
+printn:
+	clr	r0
+	div	$010,r0
+	beq	5f
+	mov	r1,-(sp)
+	mov	r0,r1
+	jsr	pc,printn
+	mov	(sp)+,r1
+5:	add	$060,r1
+	movb	r1,(r4)+
+	rts	pc
+3:	mov	(r3)+,r1
+7:	movb	(r1)+,r0
+	bne	6f
+	br	prloop
+6:	movb	r0,(r4)+
+	br	7b
+ready:
+	movb	r0,(r4)+
+	sub	$buff,r4
+	mov	$01,r0
+	mov	$buff,9f
+	mov	r4,9f+2
+	sys	write
+9:	0;	0
+	mov	(sp)+,r4
+	mov	(sp)+,r3
+	mov	(sp)+,r2
+	rts	pc
+.data
+buff:	.=.+256.
diff --git a/mach/pdp/libem/rck.s b/mach/pdp/libem/rck.s
new file mode 100644
index 000000000..029ef5a5c
--- /dev/null
+++ b/mach/pdp/libem/rck.s
@@ -0,0 +1,15 @@
+.text
+.globl rck~
+.globl trp~
+
+ERANGE	= 1
+
+rck~:
+	mov	(sp)+,r1
+	cmp	(sp),(r0)
+	blt	1f
+	cmp	(sp),02(r0)
+	ble	2f
+1:	mov	$ERANGE,-(sp)
+	jsr	pc,trp~
+2:	jmp	(r1)
diff --git a/mach/pdp/libem/ret.s b/mach/pdp/libem/ret.s
new file mode 100644
index 000000000..718948bc9
--- /dev/null
+++ b/mach/pdp/libem/ret.s
@@ -0,0 +1,31 @@
+.text
+.globl ret~,lfr~,retar
+.globl save1~
+.globl unknown~
+
+/ Size in r0
+ret~:
+	mov	r0,r1
+	beq	1f
+	asr	r1
+	add	$retar,r0
+	cmp	r0,$retend
+	bhi	9f
+3:	mov	(sp)+,-(r0)
+	sob	r1,3b
+1:	mov	r5,sp
+	mov	(sp)+,r5
+	rts	pc
+9:	jmp	unknown~
+lfr~:
+	mov	(sp)+,save1~
+	asr	r0
+	beq	4f
+	mov	$retar,r1
+5:	mov	(r1)+,-(sp)
+	sob	r0,5b
+4:	jmp	*save1~
+
+.data
+retar:	.=.+16.
+retend:
diff --git a/mach/pdp/libem/rmi.s b/mach/pdp/libem/rmi.s
new file mode 100644
index 000000000..ce36fb8f4
--- /dev/null
+++ b/mach/pdp/libem/rmi.s
@@ -0,0 +1,19 @@
+.text
+.globl rmi~
+.globl save1~,unknown~,rmi4~
+
+rmi~:
+	mov	(sp)+,save1~
+	cmp	r0,$04
+	bgt	1f
+	beq	2f
+	mov	02(sp),r1
+	sxt	r0
+	div	(sp)+,r0
+	mov	r1,(sp)
+	br	3f
+2:	jsr	pc,rmi4~
+	mov	r1,-(sp)
+	mov	r0,-(sp)
+3:	jmp	*save1~
+1:	jmp	unknown~
diff --git a/mach/pdp/libem/rmi4.s b/mach/pdp/libem/rmi4.s
new file mode 100644
index 000000000..a1e2eb413
--- /dev/null
+++ b/mach/pdp/libem/rmi4.s
@@ -0,0 +1,75 @@
+.text
+.globl rmi4~
+.globl save~,retu~
+
+rmi4~:
+	jsr	pc,save~
+	mov	02(sp),r3
+	sxt	r4
+	bpl	1f
+	neg	r3
+1:	cmp	r4,(sp)
+	bne	hardrmi4
+	mov	06(sp),r2
+	mov	04(sp),r1
+	mov	r1,r4
+	bge	2f
+	neg	r1
+	neg	r2
+	sbc	r1
+2:	mov	r4,-(sp)
+	clr	r0
+	div	r3,r0
+	mov	r1,r0
+	mov	r1,r4
+	mov	r2,r1
+	div	r3,r0
+	bvc	3f
+	mov	r2,r1
+	mov	r4,r0
+	sub	r3,r0
+	div	r3,r0
+	tst	r1
+	beq	3f
+	add	r3,r1
+3:	tst	(sp)+
+	bpl	4f
+	neg	r1
+4:	sxt	r0
+	br	9f
+hardrmi4:
+	mov	06(sp),r2
+	mov	04(sp),r1
+	bpl	5f
+	neg	r1
+	neg	r2
+	sbc	r1
+5:	clr	r0
+	mov	(sp),r3
+	bge	6f
+	neg	r3
+	neg	02(sp)
+	sbc	r3
+6:	mov	$16.,r4
+1:	clc
+	rol	r2
+	rol	r1
+	rol	r0
+	cmp	r3,r0
+	bhi	7f
+	bcs	8f
+	cmp	02(sp),r1
+	blos	8f
+7:	sob	r4,1b
+	br	2f
+8:	sub	02(sp),r1
+	sbc	r0
+	sub	r3,r0
+	sob	r4,1b
+2:	tst	04(sp)
+	bge	9f
+	neg	r0
+	neg	r1
+	sbc	r0
+9:	add	$010,sp
+	jmp	retu~
diff --git a/mach/pdp/libem/rmu.s b/mach/pdp/libem/rmu.s
new file mode 100644
index 000000000..a73830e17
--- /dev/null
+++ b/mach/pdp/libem/rmu.s
@@ -0,0 +1,19 @@
+.text
+.globl rmu~
+.globl save1~,rmu2~,rmu4~,unknown~
+
+rmu~:
+	mov	(sp)+,save1~
+	cmp	r0,$04
+	bgt	1f
+	beq	2f
+	cmp	r0,$02
+	bne	1f
+	jsr	pc,rmu2~
+	mov	r1,-(sp)
+	jmp	*save1~
+2:	jsr	pc,rmu4~
+	mov	r1,-(sp)
+	mov	r0,-(sp)
+	jmp	*save1~
+1:	jmp	unknown~
diff --git a/mach/pdp/libem/rmu2.s b/mach/pdp/libem/rmu2.s
new file mode 100644
index 000000000..77c0cfbcd
--- /dev/null
+++ b/mach/pdp/libem/rmu2.s
@@ -0,0 +1,16 @@
+.text
+.globl rmu2~
+
+rmu2~:
+	mov	04(sp),r1
+	tst	02(sp)
+	blt	1f
+	clr	r0
+	div	02(sp),r0
+2:	mov	(sp)+,r0
+	add	$04,sp
+	jmp	(r0)
+1:	cmp	02(sp),r1
+	bhi	2b
+	sub	02(sp),r1
+	br	2b
diff --git a/mach/pdp/libem/rmu4.s b/mach/pdp/libem/rmu4.s
new file mode 100644
index 000000000..2d6f0d0aa
--- /dev/null
+++ b/mach/pdp/libem/rmu4.s
@@ -0,0 +1,52 @@
+.text
+.globl rmu4~
+.globl save~,retu~
+
+rmu4~:
+	jsr	pc,save~
+	clr	r0
+	tst	(sp)
+	bne	hardrmu4
+	tst	02(sp)
+	blt	hardrmu4
+	mov	06(sp),r2
+	mov	04(sp),r1
+	mov	02(sp),r3
+	div	r3,r0
+	mov	r1,r0
+	mov	r1,r4
+	mov	r2,r1
+	div	r3,r0
+	bvc	1f
+	mov	r2,r1
+	mov	r4,r0
+	sub	r3,r0
+	div	r3,r0
+	tst	r1
+	beq	1f
+	add	r3,r1
+1:	clr	r0
+	br	2f
+hardrmu4:
+	mov	06(sp),r2
+	mov	04(sp),r1
+	mov	(sp),r3
+	mov	$17.,r4
+	br	3f
+6:	clc
+	rol	r2
+	rol	r1
+	rol	r0
+3:	cmp	r3,r0
+	bhi	4f
+	bcs	5f
+	cmp	02(sp),r1
+	blos	5f
+4:	sob	r4,6b
+	br	2f
+5:	sub	02(sp),r1
+	sbc	r0
+	sub	r3,r0
+	sob	r4,6b
+2:	add	$010,sp
+	jmp	retu~
diff --git a/mach/pdp/libem/rol.s b/mach/pdp/libem/rol.s
new file mode 100644
index 000000000..20790807e
--- /dev/null
+++ b/mach/pdp/libem/rol.s
@@ -0,0 +1,19 @@
+.text
+.globl rol~
+.globl save~,retu~
+
+rol~:
+	jsr	pc,save~
+	mov	(sp)+,r3
+3:	add	r0,sp
+	mov	r0,r1
+	asr	r1
+	clc
+1:	rol	-(sp)
+	sob	r1,1b
+	bcc	2f
+	mov	sp,r1
+	add	r0,r1
+	bis	$01,-(r1)
+2:	sob	r3,3b
+	jmp	retu~
diff --git a/mach/pdp/libem/ror.s b/mach/pdp/libem/ror.s
new file mode 100644
index 000000000..7c62e9917
--- /dev/null
+++ b/mach/pdp/libem/ror.s
@@ -0,0 +1,18 @@
+.text
+.globl ror~
+.globl save~,retu~
+
+ror~:
+	asr	r0
+	jsr	pc,save~
+	mov	(sp)+,r3
+3:	mov	sp,r1
+	mov	r0,-(sp)
+	clc
+1:	ror	(r1)+
+	sob	r0,1b
+	bcc	2f
+	bis	$0100000,02(sp)
+2:	mov	(sp)+,r0
+	sob	r3,3b
+	jmp	retu~
diff --git a/mach/pdp/libem/sar.s b/mach/pdp/libem/sar.s
new file mode 100644
index 000000000..d94bb3fed
--- /dev/null
+++ b/mach/pdp/libem/sar.s
@@ -0,0 +1,17 @@
+.text
+.globl sar~
+.globl save1~
+
+sar~:
+	mov	(sp)+,save1~
+	sub	(r0),r1
+	mov	04(r0),r0
+	mul	r0,r1
+	add	(sp)+,r1
+	asr	r0
+	beq	1f
+2:	mov	(sp)+,(r1)+
+	sob	r0,2b
+	jmp	*save1~
+1:	movb	(sp)+,(r1)
+	jmp	*save1~
diff --git a/mach/pdp/libem/save.s b/mach/pdp/libem/save.s
new file mode 100644
index 000000000..533ba5909
--- /dev/null
+++ b/mach/pdp/libem/save.s
@@ -0,0 +1,25 @@
+.text
+.globl save~,retu~,save1~
+
+save~:
+	mov	r5,savearea
+	mov	$[savearea+2],r5
+	mov	r4,(r5)+
+	mov	r3,(r5)+
+	mov	r2,(r5)+
+	mov	(sp)+,r2
+	mov	(sp)+,(r5)+
+	jmp	(r2)
+retu~:
+	mov	-(r5),-(sp)
+	mov	-(r5),r2
+	mov	-(r5),r3
+	mov	-(r5),r4
+	mov	-(r5),r5
+	rts	pc
+
+.data
+.even
+savearea:
+	.=.+12.
+save1~:	0
diff --git a/mach/pdp/libem/sbf.s b/mach/pdp/libem/sbf.s
new file mode 100644
index 000000000..d45e9610b
--- /dev/null
+++ b/mach/pdp/libem/sbf.s
@@ -0,0 +1,13 @@
+.text
+.globl sbf~
+.globl setfloat~
+
+sbf~:
+	mov	(sp)+,r1
+	jsr	pc,setfloat~
+	movf	(sp)+,r0
+	subf	(sp)+,r0
+	negf	r0
+	movf	r0,-(sp)
+	setl
+	jmp	(r1)
diff --git a/mach/pdp/libem/sbi.s b/mach/pdp/libem/sbi.s
new file mode 100644
index 000000000..79755db06
--- /dev/null
+++ b/mach/pdp/libem/sbi.s
@@ -0,0 +1,18 @@
+.text
+.globl sbi~
+.globl unknown~
+
+sbi~:
+	mov	(sp)+,r1
+	cmp	r0,$04
+	bgt	1f
+	cmp	r0,$02
+	bgt	2f
+	sub	(sp)+,(sp)
+	jmp	(r1)
+2:	sub	(sp)+,02(sp)
+	sub	(sp)+,02(sp)
+	sbc	(sp)
+	jmp	(r1)
+1:
+	jmp	unknown~
diff --git a/mach/pdp/libem/set.s b/mach/pdp/libem/set.s
new file mode 100644
index 000000000..d7972519b
--- /dev/null
+++ b/mach/pdp/libem/set.s
@@ -0,0 +1,24 @@
+.text
+.globl set~
+.globl save~,retu~,trp~
+
+ESET	= 2
+
+set~:
+	jsr	pc,save~
+	mov	r0,r2
+	asr	r0
+1:	clr	-(sp)
+	sob	r0,1b
+	div	$8.,r0
+	cmp	r0,r2
+	blo	2f
+	mov	$ESET,-(sp)
+	jsr	pc,trp~
+	jmp	retu~
+2:	add	sp,r0
+	bisb	bits(r1),(r0)
+	jmp	retu~
+
+.data
+bits:	 .byte	1,2,4,10,20,40,100,200
diff --git a/mach/pdp/libem/setfl.s b/mach/pdp/libem/setfl.s
new file mode 100644
index 000000000..00d0540c4
--- /dev/null
+++ b/mach/pdp/libem/setfl.s
@@ -0,0 +1,21 @@
+.text
+.globl setfloat~,setint~
+.globl unknown~
+
+setfloat~:
+	cmp	r0,$8.
+	bne	1f
+	rts	pc
+1:	cmp	r0,$04
+	bne	3f
+	setf
+2:	rts	pc
+3:	jmp	unknown~
+setint~:
+	cmp	r0,$04
+	bne	4f
+	setl
+	rts	pc
+4:	cmp	r0,$02
+	bne	3b
+5:	rts	pc
diff --git a/mach/pdp/libem/sigtrp.s b/mach/pdp/libem/sigtrp.s
new file mode 100644
index 000000000..8ee37269f
--- /dev/null
+++ b/mach/pdp/libem/sigtrp.s
@@ -0,0 +1,92 @@
+.text
+.globl sigtrp~
+.globl trp~,save~,retu~
+
+indir	= 0
+signal	= 48.
+
+rti	= 2
+
+sig1:	mov	sig.trp+0.,-(sp)
+	br	1f
+sig2:	mov	sig.trp+2.,-(sp)
+	br	1f
+sig3:	mov	sig.trp+4.,-(sp)
+	br	1f
+sig4:	mov	sig.trp+6.,-(sp)
+	br	1f
+sig5:	mov	sig.trp+8.,-(sp)
+	br	1f
+sig6:	mov	sig.trp+10.,-(sp)
+	br	1f
+sig7:	mov	sig.trp+12.,-(sp)
+	br	1f
+sig10:	mov	sig.trp+18.,-(sp)
+	br	1f
+sig11:	mov	sig.trp+20.,-(sp)
+	br	1f
+sig12:	mov	sig.trp+22.,-(sp)
+	br	1f
+sig13:	mov	sig.trp+24.,-(sp)
+	br	1f
+sig14:	mov	sig.trp+026.,-(sp)
+	br	1f
+sig15:	mov	sig.trp+028.,-(sp)
+	br	1f
+sig16:	mov	sig.trp+030.,-(sp)
+	br	1f
+1:
+	jsr	pc,trp~
+	rti
+
+sigtrp~:
+	jsr	pc,save~
+	tst	(sp)+
+	mov	(sp)+,r1
+	mov	(sp)+,r0
+	ble	sig.bad
+	cmp	r0,$16.
+	bhi	sig.bad
+	mov	r0,call+02
+	asl	r0
+	mov	sig.trp-2(r0),r3
+	cmp	r1,$256.
+	bhis	1f
+	mov	sig.adr-2(r0),r2
+	bne	2f
+sig.bad:
+	mov	$-1,r0
+sigbad:
+	mov	r0,-(sp)
+	mov	r0,-(sp)
+	jmp	retu~
+1:	cmp	r1,$-3
+	blo	sig.bad
+	mov	r1,r2
+	inc	r2
+	inc	r2
+2:	mov	r1,sig.trp-2(r0)
+	mov	r2,call+04
+	sys	indir ; call
+	bcs	sigbad
+	asr	r0
+	bcc	1f
+	mov	$-3,-(sp)
+	clr	-(sp)
+	jmp	retu~
+1:	mov	r3,-(sp)
+	clr	-(sp)
+	jmp	retu~
+
+.data
+call:	sys	signal;	0; 0
+sig.trp:
+	-2;	-2;	-2;	-2
+	-2;	-2;	-2;	-2
+	-2;	-2;	-2;	-2
+	-2;	-2;	-2;	-2
+sig.adr:
+	sig1;	sig2;	sig3;	sig4
+	sig5;	sig6;	sig7;	0
+	0;	sig10;	sig11;	sig12
+	sig13;	sig14;	sig15;	sig16
diff --git a/mach/pdp/libem/sim.s b/mach/pdp/libem/sim.s
new file mode 100644
index 000000000..7599b77ff
--- /dev/null
+++ b/mach/pdp/libem/sim.s
@@ -0,0 +1,28 @@
+.text
+.globl sim~
+.globl trpim~,save1~
+
+.float = 1
+
+sim~:
+	mov	(sp)+,save1~
+	mov	(sp)+,r0
+	mov	r0,trpim~
+.if .float
+	stfps	r1
+	bis	$07400,r1
+	bit	$020,r0
+	beq	0f
+	bic	$01000,r1
+0:	bit	$040,r0
+	beq	0f
+	bic	$02000,r1
+0:	bit	$01000,r0
+	beq	0f
+	bic	$04000,r1
+0:	bit	$02000,r0
+	beq	0f
+	bic	$0400,r1
+0:	ldfps	r1
+.endif
+	jmp	*save1~
diff --git a/mach/pdp/libem/sli.s b/mach/pdp/libem/sli.s
new file mode 100644
index 000000000..5b39ee2fd
--- /dev/null
+++ b/mach/pdp/libem/sli.s
@@ -0,0 +1,22 @@
+.text
+.globl sli~
+.globl save1~,unknown~
+
+sli~:
+	mov	(sp)+,save1~
+	cmp	r0,$02
+	bgt	1f
+	mov	(sp)+,r1
+	mov	(sp)+,r0
+	ash	r1,r0
+	mov	r0,-(sp)
+	jmp	*save1~
+1:	cmp	r0,$04
+	bgt	2f
+	mov	02(sp),r0
+	mov	04(sp),r1
+	ashc	(sp)+,r0
+	mov	r0,(sp)
+	mov	r1,02(sp)
+	jmp	*save1~
+2:	jmp	unknown~
diff --git a/mach/pdp/libem/sri.s b/mach/pdp/libem/sri.s
new file mode 100644
index 000000000..5620ee981
--- /dev/null
+++ b/mach/pdp/libem/sri.s
@@ -0,0 +1,25 @@
+.text
+.globl sri~
+.globl unknown~,save1~
+
+/ Size in r0
+sri~:
+	mov	(sp)+,save1~
+	cmp	r0,$02
+	bgt	1f
+	mov	(sp)+,r1
+	mov	(sp)+,r0
+	neg	r1
+	ash	r1,r0
+	mov	r0,-(sp)
+	jmp	*save1~
+1:	cmp	r0,$04
+	bgt	2f
+	mov	02(sp),r0
+	mov	04(sp),r1
+	neg	(sp)
+	ashc	(sp)+,r0
+	mov	r0,(sp)
+	mov	r1,02(sp)
+	jmp	*save1~
+2:	jmp	unknown~
diff --git a/mach/pdp/libem/sru.s b/mach/pdp/libem/sru.s
new file mode 100644
index 000000000..5f2ebef46
--- /dev/null
+++ b/mach/pdp/libem/sru.s
@@ -0,0 +1,30 @@
+.text
+.globl sru~,slu~
+.globl save1~,unknown~
+
+sru~:
+	neg	2(sp)
+slu~:
+	mov	(sp)+,save1~
+	cmp	r0,$02
+	bgt	1f
+	mov	2(sp),r1
+	clr	r0
+	ashc	(sp)+,r0
+2:	mov	r1,-(sp)
+	jmp	*save1~
+1:	cmp	r0,$04
+	bgt	3f
+	mov	02(sp),r0
+	mov	04(sp),r1
+	tst	(sp)
+	beq	4f
+	ashc	$-1,r0
+	bic	$0100000,r0
+	inc	(sp)
+	beq	4f
+	ashc	(sp)+,r0
+4:	mov	r0,(sp)
+	mov	r1,02(sp)
+	jmp	*save1~
+3:	jmp	unknown~
diff --git a/mach/pdp/libem/sto2.s b/mach/pdp/libem/sto2.s
new file mode 100644
index 000000000..3260bd722
--- /dev/null
+++ b/mach/pdp/libem/sto2.s
@@ -0,0 +1,15 @@
+.text
+.globl sto2~
+.globl save1~
+
+sto2~:
+	mov	(sp)+,save1~
+	cmp	r0,$01
+	bne	1f
+	movb	(sp),(r1)
+	tst	(sp)+
+	jmp	*save1~
+1:	asr	r0
+2:	mov	(sp)+,(r1)+
+	sob	r0,2b
+	jmp	*save1~
diff --git a/mach/pdp/libem/strhp.s b/mach/pdp/libem/strhp.s
new file mode 100644
index 000000000..47fd56bc3
--- /dev/null
+++ b/mach/pdp/libem/strhp.s
@@ -0,0 +1,24 @@
+.text
+.globl strhp~
+.globl fat~,reghp~,_end
+indir	= 0
+
+break	= 17.
+EHEAP	= 17.
+
+strhp~:
+	mov	(sp)+,r0
+	mov	(sp)+,r1
+	mov	r1,reghp~
+	cmp	r1,2f+2
+	blos	1f
+	add	$01777,r1
+	bic	$01777,r1
+	mov	r1,2f+2
+	sys	indir ; 2f
+	bcs	3f
+1:	jmp	(r0)
+3:	mov	$EHEAP,-(sp)
+	jmp	fat~
+.data
+2:	sys	break; _end
diff --git a/mach/pdp/libem/trp.s b/mach/pdp/libem/trp.s
new file mode 100644
index 000000000..1fd18ef01
--- /dev/null
+++ b/mach/pdp/libem/trp.s
@@ -0,0 +1,60 @@
+.text
+.globl trp~,fat~
+.globl trppc~,trpim~
+	write=4.
+
+fat~:
+	jsr     pc,trp~
+	4
+
+trp~:
+	mov     r0,-(sp)
+	mov     04(sp),r0
+	mov     02(sp),04(sp)
+	mov     (sp),02(sp)
+	mov     r1,(sp)
+	cmp     r0,$16.
+	jhis    0f
+	mov     $01,r1
+	ashc    r0,r1
+	bit     r1,trpim~
+	bne     8f
+0:      mov     r2,-(sp)
+	mov     r3,-(sp)
+	mov     r4,-(sp)
+	movf    r0,-(sp)
+	movf    r1,-(sp)
+	movf    r2,-(sp)
+	movf    r3,-(sp)
+	stfps   -(sp)
+	mov     r0,-(sp)
+	mov     trppc~,r0
+	beq     9f
+	clr     trppc~
+	jsr     pc,(r0)
+	tst     (sp)+
+	ldfps   (sp)+
+	movf    (sp)+,r3
+	movf    (sp)+,r2
+	movf    (sp)+,r1
+	movf    (sp)+,r0
+	mov     (sp)+,r4
+	mov     (sp)+,r3
+	mov     (sp)+,r2
+8:      mov     (sp)+,r1
+	mov     (sp)+,r0
+	rts     pc
+9:      mov	(sp)+,r0
+	mov	$buf+11,r1
+	mov	$4,r2
+1:	mov	r0,r3
+	bic	$177770,r3
+	bisb	r3,-(r1)
+	ash	$-3,r0
+	sob	r2,1b
+	mov	$2,r0
+	sys	write;buf;11.
+	4
+
+.data
+buf:	<err 00000\n>
diff --git a/mach/pdp/libem/unknown.s b/mach/pdp/libem/unknown.s
new file mode 100644
index 000000000..623f0b11c
--- /dev/null
+++ b/mach/pdp/libem/unknown.s
@@ -0,0 +1,9 @@
+.text
+.globl unknown~
+.globl fat~
+
+EILLSIZ	= 19.
+
+unknown~:
+	mov	$EILLSIZ,-(sp)
+	jmp	fat~
diff --git a/mach/pdp/libem/xor.s b/mach/pdp/libem/xor.s
new file mode 100644
index 000000000..213205963
--- /dev/null
+++ b/mach/pdp/libem/xor.s
@@ -0,0 +1,13 @@
+.globl xor~
+.globl save~,retu~
+
+xor~:
+	jsr	pc,save~
+	mov	sp,r1
+	add	r0,r1
+	asr	r0
+1:
+	mov	(sp)+,r2
+	xor	r2,(r1)+
+	sob	r0,1b
+	jmp	retu~