fixes

vt100.csi.S

@@ -397,7 +397,7 @@ mode_DECOM
 	stz y
 	cpy #0
 	beq :rts
-	lda #DECTM
+	lda DECTM
 	sta y
 
 	phy

vt100.main.S

@@ -68,12 +68,13 @@ init
 	lda #$01
 	sta cursor_base+2
 
+	lda #"  " ; 16-bit
+	sta erase_char
+
 	sep #$30
 
 	lda #"_"
 	sta cursor_char
-	lda #" "
-	sta erase_char
 
 
 	lda #23
@@ -241,7 +242,7 @@ ctrl_0c ; form feed.
 
 :lf
 	lda y
-	cmp #DECBM
+	cmp DECBM
 	bne :simple
 
 *	lda #" " ; needs to factor in reverse video

vt100.screen.S

@@ -315,14 +315,12 @@ scroll_up ent
 
 * mvn 1,1 first so mvn 0,0 will restore b
 :cp	mac
-	lda #$40
-	lda #40
+	lda #40-1
 	ldx #]1
 	ldy #]2
 	mvn $010000,$010000
 
-	lda #$40
-	lda #40
+	lda #40-1
 	ldx #]1
 	ldy #]2
 	mvn $000000,$000000
@@ -409,14 +407,12 @@ scroll_down ent
 
 
 :cp	mac
-	lda #$40
-	lda #40
+	lda #40-1
 	ldx #]1
 	ldy #]2
 	mvn $010000,$010000
 
-	lda #$40
-	lda #40
+	lda #40-1
 	ldx #]1
 	ldy #]2
 	mvn $000000,$000000