buffer outgoing keystrokes

this also adds a hexdump in the CDA for the outgoing buffer
in local mode, "incoming" data is read from the outgoing buffer.
Currently data is (potentially) sent on each run of the main loop.
I thought about using the TX empty interrupt but it still needs to be
kicked off at some point (unlike incoming data)

vt100.cda.S

@@ -52,7 +52,8 @@ page	ds 2
 
 
 pages	dw variables
-	dw hexdump
+	dw hexdump_r
+	dw hexdump_w
 	dw ssc_registers
 
 shutdown
@@ -83,8 +84,7 @@ main
 	jsr clear_inner
 	ldx page
 	jsr (pages,x)
-*	jsr variables
+
-*	jsr hexdump
 
 
 :keyloop
@@ -112,14 +112,14 @@ main
 	dec
 	dec
 	bpl :lok
-	lda #$04
+	lda #$05
 :lok	sta page
 	bra main
 
 :right	lda page
 	inc
 	inc
-	cmp #$04+1
+	cmp #$05+1
 	bcc :rok
 	lda #0
 :rok	sta page
@@ -263,6 +263,7 @@ box
 variables
 	php
 	sep #$20
+	jsr local
 	jsr decanm
 	jsr dectm
 	jsr decbm
@@ -276,10 +277,19 @@ variables
 	plp
 	rts
 
+local
+	mx %10
+	ldy #line_4+4
+	ldx #:str
+	jsr print_xy_str
+	lda DPAGE+LOCAL
+	jmp print_on_off
+
+:str	asc "LOCAL:   ",00
 
 decanm
 	mx %10
-	ldy #line_4+4
+	ldy #line_5+4
 	ldx #:str
 	jsr print_xy_str
 	lda DPAGE+DECANM
@@ -297,7 +307,7 @@ decanm
 
 dectm
 	mx %10
-	ldy #line_5+4
+	ldy #line_6+4
 	ldx #:str
 	jsr print_xy_str
 	lda DPAGE+DECTM
@@ -308,7 +318,7 @@ dectm
 
 decbm
 	mx %10
-	ldy #line_6+4
+	ldy #line_7+4
 	ldx #:str
 	jsr print_xy_str
 	lda DPAGE+DECBM
@@ -320,7 +330,7 @@ decbm
 
 decom
 	mx %10
-	ldy #line_7+4
+	ldy #line_8+4
 	ldx #:str
 	jsr print_xy_str
 	lda DPAGE+DECOM
@@ -330,7 +340,7 @@ decom
 
 deckpam
 	mx %10
-	ldy #line_8+4
+	ldy #line_9+4
 	ldx #:str
 	jsr print_xy_str
 	lda DPAGE+DECKPAM
@@ -340,7 +350,7 @@ deckpam
 
 decckm
 	mx %10
-	ldy #line_9+4
+	ldy #line_10+4
 	ldx #:str
 	jsr print_xy_str
 	lda DPAGE+DECCKM
@@ -351,7 +361,7 @@ decckm
 
 decawm
 	mx %10
-	ldy #line_10+4
+	ldy #line_11+4
 	ldx #:str
 	jsr print_xy_str
 	lda DPAGE+DECAWM
@@ -362,7 +372,7 @@ decawm
 
 decscnm
 	mx %10
-	ldy #line_11+4
+	ldy #line_12+4
 	ldx #:str
 	jsr print_xy_str
 	lda DPAGE+DECSCNM
@@ -373,7 +383,7 @@ decscnm
 
 lnm
 	mx %10
-	ldy #line_12+4
+	ldy #line_13+4
 	ldx #:str
 	jsr print_xy_str
 	lda DPAGE+LNM
@@ -384,7 +394,7 @@ lnm
 
 sgr
 	mx %10
-	ldy #line_13+4
+	ldy #line_14+4
 	ldx #:str
 	jsr print_xy_str
 	lda DPAGE+SGR
@@ -516,7 +526,8 @@ print_hex
 	iny
 	rts
 
-hexdump
+
+hexdump_r
 *
 * $1e00 buffer
 *
@@ -528,7 +539,7 @@ hexdump
 :count	equ 8
 :row	equ 10
 :c	equ 12
-
+:ptr	equ 14
 
 	mx %00
 	debug hexdump
@@ -621,6 +632,113 @@ hexdump
 	plp
 	rts
 
+
+hexdump_w
+*
+* $1d00 buffer
+*
+
+:screen	equ 0
+:screen2	equ 2
+:offset	equ 4
+:ptr	equ 6
+:count	equ 8
+:row	equ 10
+:c	equ 12
+:ptr	equ 14
+
+	mx %00
+	debug hexdump
+
+	php
+	lda #0
+
+	stz :offset
+
+	sep #$20
+
+	ldx #4*2
+	stx :row
+
+	lda DPAGE+write_q_tail
+	sec
+	sbc #8*16
+	sta :offset
+
+
+
+:one_row
+
+	ldx :row
+	ldy text,x
+	sty :screen
+	sty :screen2
+
+
+
+	lda #8
+	sta :count
+
+:one_byte
+
+	ldx :offset
+	lda $1d00,x
+
+	sta :c
+	lsr
+	lsr
+	lsr
+	lsr
+	tax
+	lda hex,x
+	ldy :screen
+	sta |$04,y
+	iny
+	lda :c
+	and #$0f
+	tax
+	lda hex,x
+	sta |$04,y
+	iny
+	lda #" "
+	sta |$04,y
+	iny
+	sty :screen
+
+
+* ascii
+	ldx #"."
+	lda :c
+	cmp #$20
+	blt :dot
+	cmp #$80
+	bcs :dot
+	ora #$80
+	tax
+:dot
+	txa
+	ldy :screen2
+	sta |8*3+4,y
+	iny
+	sty :screen2
+
+
+	inc :offset
+	dec :count
+	bne :one_byte
+
+
+	ldx :row
+	inx
+	inx
+	stx :row
+	cpx #20*2
+	bcc :one_row
+
+	plp
+	rts
+
+
 hex	asc "0123456789abcdef"
 
 

vt100.key.S

@@ -10,7 +10,8 @@
 
 	mx %11
 
-	ext dispatch
+*	ext dispatch
+	ext write_modem
 
 
 kmShift		equ %0000_0001
@@ -22,6 +23,9 @@ kmUpdateMod	equ %0010_0000
 kmOption	equ %0100_0000
 kmCommand	equ %1000_0000
 
+dispatch
+	jmp write_modem
+
 keypress ent
 	debug keypress
 	lda KBD

vt100.main.S

@@ -11,7 +11,7 @@
 
 	ext scroll_down
 	ext recalc_cursor,recalc_cursor_x,recalc_cursor_y
-	ext write_modem,read_modem,init_modem,modem_vector,reset_modem_buffer
+	ext modem_io,init_modem,modem_vector,reset_modem_buffer
 	ext keypress
 	ext disable_cursor,enable_cursor,cursor_vector
 	ext erase_screen,fill_screen
@@ -38,23 +38,16 @@ main	debug main
 
 
 loop
-	bit LOCAL
+	jsr keypress ; check for a keypress, write data to out buffer.
-	bmi :kb
+	jsr modem_io ; 
-	jsr read_modem
+	bcc :nope
-	bcc :kb
 	pha
 	jsr disable_cursor
 	pla
 	jsr vt100
-:kb	
+	bra loop
-	jsr keypress
 
-*
+:nope	; no modem data, re-enable the cursor.
-* if there is pending modem data, don't re-enable the cursor yet.
-* 
-	lda read_q_head
-	cmp read_q_tail
-	bne loop
 	jsr enable_cursor
 	bra loop
 
@@ -189,16 +182,16 @@ reset	ent
 	rts
 
 
-dispatch ent
+*dispatch ent
-	mx %11
+*	mx %11
-* a = character to xmit
+** a = character to xmit
-	bit LOCAL
+*	bit LOCAL
-	bmi :local
+*	bmi :local
-	jmp write_modem
+*	jmp write_modem
-:local
+*:local
-	pha
+*	pha
-	jsr disable_cursor
+*	jsr disable_cursor
-	pla
+*	pla
 
 * fall through
 

vt100.modem.S

@@ -7,6 +7,7 @@
 	mx %11
 	cas se
 	use vt.equ
+	use debug
 
 SCCBREG		equ $c038
 SCCAREG		equ $c039
@@ -88,7 +89,7 @@ init_modem ent
 	db 9,%00_0_0_1_0_1_0 ; master interrupts enabled.
 	db -1,-1
 
-write_modem ent
+write_modem_sync ent
 	mx %11
 * a: byte to send
 	tay ; save
@@ -110,6 +111,7 @@ write_modem ent
 	plp
 	rts
 
+
 read_modem_sync ent
 * c set if data read
 * v set if overrun
@@ -146,6 +148,7 @@ read_modem_sync ent
 :rts	rts
 
 
+write_buffer equ $1d00
 read_buffer equ $1e00
 
 modem_vector	ent
@@ -202,6 +205,123 @@ modem_int
 	plb
 	rtl
 
+
+
+modem_io ent
+	debug modem_io
+
+	mx %11
+	php
+	sei
+	bit LOCAL
+	bmi :local
+
+:write
+* send any outbound data...
+
+:mask	= %0010_0100  ; tx buffer empty, clear to send
+	ldx write_q_tail
+	cpx write_q_head
+	beq :read
+
+	lda SCCBREG ; sync
+	stz SCCBREG
+	lda SCCBREG
+	and #:mask
+	cmp #:mask
+	bne :read
+
+*	ldx write_q_tail
+	lda write_buffer,x
+	sta SCCBDATA
+	inc write_q_tail
+:read
+	ldx read_q_tail
+	cpx read_q_head
+	beq :nope
+	lda read_buffer,x
+	inc read_q_tail
+	plp
+	sec
+	rts
+
+:nope
+	plp
+	clc
+	rts
+	
+
+:local
+	ldx write_q_tail
+	cpx write_q_head
+	beq :nope
+	lda write_buffer,x
+	inc write_q_tail
+	plp
+	sec
+	rts
+
+
+
+write_modem ent
+write_modem_async ent
+
+	mx %11
+	php
+	sei
+
+*	bit LOCAL
+*	bmi :local
+
+	ldx write_q_head
+	sta write_buffer,x
+	inc write_q_head
+	plp
+	rts
+*:local
+*	ldx read_q_head
+*	sta read_buffer,x
+*	inc read_q_head
+*	plp
+*	rts
+
+
+write_modem_str ent
+
+; y = address of string (0-terminated)
+; inc write_q_head vs inx
+; because it wraps at $ff
+
+	mx %10
+	php
+	sei
+*	bit LOCAL
+*	bmi :local
+
+:loop	lda |$0000,y
+	beq :fini
+	ldx write_q_head
+	sta write_buffer,x
+	inc write_q_head
+	iny
+	bra :loop
+
+*:local	lda |$0000,y
+*	beq :fini
+*	ldx read_q_head
+*	sta read_buffer,x
+*	inc read_q_head
+*	iny
+*	bra :local
+
+
+:fini
+	plp
+	rts
+
+
+
+
 read_modem ent
 read_modem_async ent