diff --git a/libsrc/geos-cbm/conio/_scrsize.s b/libsrc/geos-cbm/conio/_scrsize.s
index eaa151bd8..fb4399f79 100644
--- a/libsrc/geos-cbm/conio/_scrsize.s
+++ b/libsrc/geos-cbm/conio/_scrsize.s
@@ -18,6 +18,7 @@
 .segment        "INIT"
 
 initscrsize:
+.ifdef  __GEOS_CBM__
 	lda	graphMode
 	bpl	L1
 	lda	#80		; 80 columns (more or less)
@@ -25,6 +26,11 @@ initscrsize:
 L1:	lda	#40		; 40 columns (more or less)
 	sta	xsize
 	lda	#24		; something like that for Y size
+.else
+	lda	#70		; 70 columns (more or less)
+	sta	xsize
+	lda	#23		; something like that for Y size
+.endif
 	sta	ysize
 	ldx	#1
 	stx	cursor_r
diff --git a/libsrc/geos-cbm/conio/clrscr.s b/libsrc/geos-cbm/conio/clrscr.s
index af22b6a7c..50be5b094 100644
--- a/libsrc/geos-cbm/conio/clrscr.s
+++ b/libsrc/geos-cbm/conio/clrscr.s
@@ -30,6 +30,7 @@ _clrscr:
 	    inx
 	    stx cursor_r
 	    jsr fixcursor		; home cursor
+.ifdef  __GEOS_CBM__
 	    lda #199
 	    sta r2H
 	    lda graphMode
@@ -39,7 +40,14 @@ _clrscr:
 	    bne L99
 L40:	    lda #>319			; 40 columns
 	    ldx #<319
-L99:	    sta r4H
+L99:
+.else
+	    lda #191
+	    sta r2H
+	    lda #>559
+	    ldx #<559
+.endif
+	    sta r4H
 	    stx r4L
 	    jsr Rectangle
 	    pla