diff --git a/apple2gs.equ.S b/apple2gs.equ.S
index 8a4f31d..11136c0 100644
--- a/apple2gs.equ.S
+++ b/apple2gs.equ.S
@@ -31,7 +31,11 @@ SGADDRH		equ $c03f	; Sound GLU address reg high
 
 * interrupt vectors.  JMP ABSLONG.
 IRQ1SEC		equ $e10054
+IRQMOUSE	equ $e10034
 IRQQTR		equ $e10038
 IRQVBL		equ $e10030
 IRQSND		equ $e1002c
+IRQSCAN		equ $e10028
+IRQSERIAL	equ $e10024
+IRQATALK	equ $e10020
 
diff --git a/vt100.main.S b/vt100.main.S
index fa185da..8b7cb07 100644
--- a/vt100.main.S
+++ b/vt100.main.S
@@ -11,9 +11,10 @@
 
 	ext scroll_down
 	ext recalc_cursor,recalc_cursor_x,recalc_cursor_y
-	ext write_modem,read_modem,init_modem,keypress
+	ext write_modem,read_modem,init_modem,modem_vector
+	ext keypress
 	ext disable_cursor,enable_cursor,cursor_vector
-	ext erase_screen
+	ext erase_screen,fill_screen
 	ext init_tabs
 	ext init_audio
 	ext init_cda
@@ -49,6 +50,10 @@ loop
 	bra loop
 
 init
+	mx %11
+	lda #" "
+	jsr fill_screen ; erase first to prevent flash if going 40->80 columns.
+
 	sta TXTSET
 	sta SET80VID
 	sta SETALTCHAR
@@ -72,11 +77,18 @@ init
 
 	lda #$0080
 	sta cursor_state
+
 	sei
 	lda cursor_vector
 	stal IRQ1SEC
 	lda cursor_vector+2
 	stal IRQ1SEC+2
+
+	lda modem_vector
+	stal IRQSERIAL
+	lda modem_vector+2
+	stal IRQSERIAL+2
+
 	cli
 
 	lda #0 ; clear high byte
@@ -90,12 +102,14 @@ init
 	lda #23
 	sta DECBM
 	lda #$80
-	sta LOCAL
+*	sta LOCAL
+	sta DECANM
 
-	lda #st_vt52
+*	lda #st_vt52
+	lda #st_vt100
 	sta state
 
-	jsr erase_screen
+*	jsr erase_screen
 	jsr init_modem
 	jsr init_tabs
 	jsr init_audio
diff --git a/vt100.modem.S b/vt100.modem.S
index 45eea3d..09aa85b 100644
--- a/vt100.modem.S
+++ b/vt100.modem.S
@@ -14,6 +14,8 @@ SCCBDATA	equ $c03a
 SCCADATA	equ $c03b
 
 
+SerFlag		equ $e10104 ; 
+
 *
 * scc speed:
 * 
@@ -23,10 +25,17 @@ SCCADATA	equ $c03b
 * clock mode = 1x, 16x, 32x, or 64x (selected via write register 4 bits 6/7)
 * clock = 3.6864 MHz crystal (scc runs at 14.31818 / 4 = ~ 3.58 Mhz)
 * time constant = write register 12 (low) + 13 (high)
-
+*
+*
+* see IIgs TN #18 - Do-It-Yourself SCC Access
 
 init_modem ent
 *	sep #$30
+
+
+	stz q_head
+	stz q_tail
+
 * reset channel B (modem port)
 	ldx #9
 	lda #%01_0_1_0_0_0_1
@@ -114,9 +123,10 @@ init_modem ent
 	stx SCCBREG
 	sta SCCBREG
 
-* disable interrupts
+* enable interrupts
 	ldx #1
-	lda #0
+*	lda #0
+	lda #%0_0_0_10_0_0_0 ; inr on rx or special condition.
 	stx SCCBREG
 	sta SCCBREG
 
@@ -124,15 +134,20 @@ init_modem ent
 	lda SCCBREG
 
 
-* status, visible, master interrupts disabled
+* no vector, master interrupts enabled
 	ldx #9
-	lda #%00_0_1_0_0_0_1
+	lda #%00_0_0_1_0_1_0
 	stx SCCBREG
 	sta SCCBREG
 	nop
 	nop
 
 
+* adjust SerFlag so serial IRQs will be handled.
+	lda >SerFlag
+	ora #%00_000_111 ; channel B interrupts.
+	sta >SerFlag
+
 	rts
 
 write_modem ent
@@ -151,7 +166,7 @@ write_modem ent
 	sty SCCBDATA
 	rts
 
-read_modem ent
+read_modem_sync ent
 * c set if data read
 * v set if overrun
 	mx %11
@@ -168,6 +183,9 @@ read_modem ent
 	lda SCCBREG
 	and #%0010_0000
 	beq :ok
+* indicate overrun...
+	lda #"x"
+	sta |$07d0+20
 * clear the overrun
 	lda #$30 ; reg0, error reset.
 	sta SCCBREG
@@ -178,8 +196,97 @@ read_modem ent
 *	sta SCCBREG
 *	lda SCCBREG
 	lda SCCBDATA
+
+* debugging...
+	ldx :debug
+	sta $1e00,x
+	inc :debug
+
 	sec
 :rts	rts
 
 
+:debug	ds 2
+
+buffer equ $1d00
+
+modem_vector	ent
+	jml modem_int
+modem_int
+*
+* called in 8-bit native mode, interrupts disabled.
+* d = unknown
+* a/x/y don't need to be preserved.
+* return carry clear if handled, carry set if not.
+
+
+* check/clear overrun?
+	mx %11
+
+	phb
+	phk
+	plb
+
+	stz SCCBREG
+	lda SCCBREG
+	and #%0000_0001 ; rx ready.
+	beq :nope
+
+:read
+	lda SCCBDATA
+	ldx q_tail
+	sta buffer,x
+	inc q_tail
+
+* more?
+	stz SCCBREG
+	lda SCCBREG
+	and #%0000_0001 ; rx ready.
+	bne :read
+	clc
+	bra :finish
+
+:nope
+
+	sec
+:finish
+* reset errors.
+	lda #%00_110_000
+	stz SCCBREG
+	sta SCCBREG
+
+* reset highest ius
+	lda #%00_111_000
+	stz SCCBREG
+	sta SCCBREG
+
+	plb
+	rtl
+
+read_modem ent
+read_modem_async ent
+
+	mx %11
+
+	php
+	sei
+	ldx q_head
+	cpx q_tail
+	beq :nope
+
+	lda buffer,x
+	inc q_head
+	plp
+	sec
+	rts
+
+:nope
+	plp
+	clc
+	rts
+
+q_head	ds 2
+q_tail	ds 2
+*buffer	ds 256
+
 	sav vt100.modem.L
diff --git a/vt100.vt52.S b/vt100.vt52.S
index 4fce9fa..8431cdf 100644
--- a/vt100.vt52.S
+++ b/vt100.vt52.S
@@ -82,6 +82,7 @@ esc_lt
 * (which we don't support anyhow.)
 	lda #$80
 	sta DECANM
+*	stz MOUSETEXT
 	lda #st_vt100
 	sta state
 	rts
@@ -176,10 +177,13 @@ esc_H ; cursor home
 esc_F ; enter graphics mode
 *	lda #%0010
 *	tsb mode
+	lda #$80
+*	tsb MOUSETEXT
 	rts
 esc_G ; exit graphics mode
 *	lda #%0010
 *	trb mode
+*	stz MOUSETEXT
 	rts
 
 esc_Y ; direct cursor address