diff --git a/src/crt/i48shrs_1.src b/src/crt/i48shrs_1.src
new file mode 100644
index 000000000..a1825becd
--- /dev/null
+++ b/src/crt/i48shrs_1.src
@@ -0,0 +1,24 @@
+	.assume	adl=1
+
+	.section	.text
+	.global	__i48shrs_1
+	.type	__i48shrs_1, @function
+
+__i48shrs_1:
+	push	hl
+	scf
+	sbc	hl, hl
+	add	hl, sp
+	push	de
+	sra	(hl)
+	pop	de
+	inc	hl
+	inc	hl
+	inc	hl
+	rr	d
+	rr	e
+	rr	(hl)
+	pop	hl
+	rr	h
+	rr	l
+	ret
diff --git a/src/crt/i48shru_1.src b/src/crt/i48shru_1.src
new file mode 100644
index 000000000..6159a9848
--- /dev/null
+++ b/src/crt/i48shru_1.src
@@ -0,0 +1,24 @@
+	.assume	adl=1
+
+	.section	.text
+	.global	__i48shru_1
+	.type	__i48shru_1, @function
+
+__i48shru_1:
+	push	hl
+	scf
+	sbc	hl, hl
+	add	hl, sp
+	push	de
+	srl	(hl)
+	pop	de
+	inc	hl
+	inc	hl
+	inc	hl
+	rr	d
+	rr	e
+	rr	(hl)
+	pop	hl
+	rr	h
+	rr	l
+	ret
diff --git a/src/crt/ishrs_1_fast.src b/src/crt/ishrs_1.src
similarity index 57%
rename from src/crt/ishrs_1_fast.src
rename to src/crt/ishrs_1.src
index 17970e4da..d1464ba72 100644
--- a/src/crt/ishrs_1_fast.src
+++ b/src/crt/ishrs_1.src
@@ -1,10 +1,10 @@
 	.assume	adl=1
 
 	.section	.text
-	.global	__ishrs_1_fast
-	.type	__ishrs_1_fast, @function
+	.global	__ishrs_1
+	.type	__ishrs_1, @function
 
-__ishrs_1_fast:
+__ishrs_1:
 	push	hl
 	ld	hl, 2
 	add	hl, sp
diff --git a/src/crt/ishru_1_fast.src b/src/crt/ishru_1.src
similarity index 57%
rename from src/crt/ishru_1_fast.src
rename to src/crt/ishru_1.src
index 765437bc1..a88c783d5 100644
--- a/src/crt/ishru_1_fast.src
+++ b/src/crt/ishru_1.src
@@ -1,10 +1,10 @@
 	.assume	adl=1
 
 	.section	.text
-	.global	__ishru_1_fast
-	.type	__ishru_1_fast, @function
+	.global	__ishru_1
+	.type	__ishru_1, @function
 
-__ishru_1_fast:
+__ishru_1:
 	push	hl
 	ld	hl, 2
 	add	hl, sp
diff --git a/src/crt/llshl_1_fast.src b/src/crt/llshl_1.src
similarity index 56%
rename from src/crt/llshl_1_fast.src
rename to src/crt/llshl_1.src
index 830b4f510..dfb491ca7 100644
--- a/src/crt/llshl_1_fast.src
+++ b/src/crt/llshl_1.src
@@ -1,10 +1,10 @@
 	.assume	adl=1
 
 	.section	.text
-	.global	__llshl_1_fast
-	.type	__llshl_1_fast, @function
+	.global	__llshl_1
+	.type	__llshl_1, @function
 
-__llshl_1_fast:
+__llshl_1:
 	add	hl, hl
 	ex	de, hl
 	adc	hl, hl
diff --git a/src/crt/llshrs_1_fast.src b/src/crt/llshrs_1.src
similarity index 65%
rename from src/crt/llshrs_1_fast.src
rename to src/crt/llshrs_1.src
index 68d26bbe8..0e6e2d786 100644
--- a/src/crt/llshrs_1_fast.src
+++ b/src/crt/llshrs_1.src
@@ -1,14 +1,15 @@
 	.assume	adl=1
 
 	.section	.text
-	.global	__llshrs_1_fast
-	.type	__llshrs_1_fast, @function
+	.global	__llshrs_1
+	.type	__llshrs_1, @function
 
-__llshrs_1_fast:
+__llshrs_1:
 	push	hl
-	push	de
-	ld	hl, 2
+	scf
+	sbc	hl, hl
 	add	hl, sp
+	push	de
 	sra	b
 	rr	c
 	rr	(hl)
diff --git a/src/crt/llshru_1_fast.src b/src/crt/llshru_1.src
similarity index 65%
rename from src/crt/llshru_1_fast.src
rename to src/crt/llshru_1.src
index 1a6f83873..487c9362d 100644
--- a/src/crt/llshru_1_fast.src
+++ b/src/crt/llshru_1.src
@@ -1,14 +1,15 @@
 	.assume	adl=1
 
 	.section	.text
-	.global	__llshru_1_fast
-	.type	__llshru_1_fast, @function
+	.global	__llshru_1
+	.type	__llshru_1, @function
 
-__llshru_1_fast:
+__llshru_1:
 	push	hl
-	push	de
-	ld	hl, 2
+	scf
+	sbc	hl, hl
 	add	hl, sp
+	push	de
 	srl	b
 	rr	c
 	rr	(hl)
diff --git a/src/crt/lshrs_1_fast.src b/src/crt/lshrs_1.src
similarity index 58%
rename from src/crt/lshrs_1_fast.src
rename to src/crt/lshrs_1.src
index 11c4f8fdf..cc47736ef 100644
--- a/src/crt/lshrs_1_fast.src
+++ b/src/crt/lshrs_1.src
@@ -1,10 +1,10 @@
 	.assume	adl=1
 
 	.section	.text
-	.global	__lshru_1_fast
-	.type	__lshru_1_fast, @function
+	.global	__lshrs_1
+	.type	__lshrs_1, @function
 
-__lshru_1_fast:
+__lshrs_1:
 	push	hl
 	ld	hl, 2
 	add	hl, sp
diff --git a/src/crt/lshru_1_fast.src b/src/crt/lshru_1.src
similarity index 58%
rename from src/crt/lshru_1_fast.src
rename to src/crt/lshru_1.src
index 59215d650..8aa1bb3ae 100644
--- a/src/crt/lshru_1_fast.src
+++ b/src/crt/lshru_1.src
@@ -1,10 +1,10 @@
 	.assume	adl=1
 
 	.section	.text
-	.global	__lshru_1_fast
-	.type	__lshru_1_fast, @function
+	.global	__lshru_1
+	.type	__lshru_1, @function
 
-__lshru_1_fast:
+__lshru_1:
 	push	hl
 	ld	hl, 2
 	add	hl, sp