diff --git a/src/fileioc/fileioc.asm b/src/fileioc/fileioc.asm
index 138a2fb08..8394ca2a1 100644
--- a/src/fileioc/fileioc.asm
+++ b/src/fileioc/fileioc.asm
@@ -462,8 +462,8 @@ ti_SetArchiveStatus:
 	call	ti.ChkFindSym
 	jp	c, util_ret_neg_one
 	call	ti.ChkInRam
-	jr	z, .save_ptrs
-	call	util_skip_archive_header
+	; jr	z, .save_ptrs
+	call	nz, util_skip_archive_header
 .save_ptrs:
 	push	hl
 	call	util_get_vat_ptr
@@ -783,13 +783,9 @@ ti_DeleteVar:
 ;  sp + 6 : variable type
 ; return:
 ;  hl = 0 if failure
-	pop	hl
-	pop	de
-	pop	bc
-	push	bc
-	push	de
-	push	hl
-	ld	a, c
+	ld	hl, 6
+	add	hl, sp
+	ld	a, (hl)
 ;	jr	ti_Delete.start		; emulated by dummifying next instruction:
 	db	$fe			; ld a, ti.AppVarObj -> cp a, $3E \ dec d
 assert ti.AppVarObj = $15
@@ -948,24 +944,19 @@ ti_Detect:
 	ld	(.smc_flag), a
 	push	ix
 	ld	ix, 0
+	lea	bc, ix + 0
 	add	ix, sp
 	ld	hl, (ix + 9)
-	add	hl, bc
-	or	a, a
-	sbc	hl, bc
+	adc	hl, bc
 	jr	nz, .detectall		; if null, then detect everything
 	ld	hl, .fdetectall
 	ld	(ix + 9), hl
 .detectall:
 	ld	hl, (ix + 6)
-	add	hl, bc
-	or	a, a
-	sbc	hl, bc
+	adc	hl, bc
 	jr	z, .fstart
 	ld	hl, (hl)
-	add	hl, bc
-	or	a, a
-	sbc	hl, bc
+	adc	hl, bc
 	jr	nz, .fdetect
 .fstart:
 	ld	hl, (ti.progPtr)