From 26ceb7aa5051054bb737a2a8a26fb5df36c8e3f9 Mon Sep 17 00:00:00 2001
From: Kelvin Sherlock <ksherlock@gmail.com>
Date: Sat, 23 Oct 2021 12:25:20 -0400
Subject: [PATCH] start of a CDA to control vt100 parameters.

---
 apple2gs.equ.S |   3 +
 vt100.cda.S    | 191 +++++++++++++++++++++++++++++++++++++++++++++++++
 vt100.link.S   |   2 +
 vt100.main.S   |   2 +
 4 files changed, 198 insertions(+)
 create mode 100644 vt100.cda.S

diff --git a/apple2gs.equ.S b/apple2gs.equ.S
index cc986ce..8a4f31d 100644
--- a/apple2gs.equ.S
+++ b/apple2gs.equ.S
@@ -1,4 +1,7 @@
+
+CLR80VID	equ $c00c
 SET80VID	equ $c00d
+CLRALTCHAR	equ $c00e
 SETALTCHAR	equ $c00f
 TXTSET		equ $c051
 KEYMOD		equ $c025
diff --git a/vt100.cda.S b/vt100.cda.S
new file mode 100644
index 0000000..583c56e
--- /dev/null
+++ b/vt100.cda.S
@@ -0,0 +1,191 @@
+
+
+	lst off
+	rel
+
+	xc
+	xc
+	cas se
+	tbx on ; qasm
+
+	use apple2gs.equ
+
+
+* alternate character set
+* $00-$1f = upper inverse ( asci value - $40)
+* $20-$3f = special inverse (ascii value)
+* $40-$4f = mouse text 
+* $60-$7f = lower inverse (= ascii value)
+* $80-$9f = upper [redundant]
+* $a0-$bf = special (high ascii)
+* $c0-$df = upper (high ascii)
+* $e0-$ff = lower (high ascii)
+
+
+* 40-column control panel
+* TODO - if 80 column set in preferences, draw centered in 80-column mode
+
+init_cda ent
+	php
+	rep #$30
+	psl #handle
+	_InstallCDA
+	plp
+	rts
+
+handle	adrl Header ; can use a fake handle for now, until we need to _RemoveCDA
+Header
+	str 'Virtual Terminal'
+	adrl start
+	adrl shutdown
+
+shutdown
+	mx %00
+	rtl
+
+start
+	mx %00
+
+	phb
+	phd
+
+	phk
+	plb
+
+	sep #$30
+	sta TXTSET
+	sta CLR80VID
+	sta SETALTCHAR
+	rep #$30
+
+	jsr clear
+	jsr box
+
+
+:keyloop
+	lda KBD
+	bpl :keyloop
+	sta KEYSTROBE
+
+	pld
+	plb
+	rtl
+
+
+clear
+	ldx #23*2
+	lda #"  "
+:loop
+	ldy text,x
+
+]offset	equ 0
+	lup 20
+	sta |0+]offset,y
+]offset	equ ]offset+2
+	--^
+
+	dex
+	dex
+	bpl :loop
+	rts
+
+
+box
+	php
+
+* top line
+	lda #"_ "
+	sta $0400+38
+
+	lda #" _"
+	sta $0400
+
+	lda #"__"
+	ldx #34
+
+]loop	sta $0400+2,x
+	dex
+	dex
+	bpl ]loop
+
+* bottom line.
+* 'L' = $4c = _ but high 
+	lda #'L '!$8000 ; keep ' ' high ascii.
+	sta $07d0+38
+
+	lda #' L'!$0080 ; keep ' ' high ascii.
+	sta $07d0
+
+	lda #'LL'
+	ldx #34
+
+]loop	sta $07d0+2,x
+	dex
+	dex
+	bpl ]loop
+
+
+* sides
+	sep #$20
+	lda #'Z'
+	ldx #21*2 ; skip top/bottom lines.
+]loop	ldy text+2,x
+	sta |$0,y
+	dex
+	dex
+	bpl ]loop
+
+	sep #$20
+	lda #'_'
+	ldx #21*2 ; skip top/bottom lines.
+]loop	ldy text+2,x
+	sta |$0+39,y
+	dex
+	dex
+	bpl ]loop
+
+
+	plp
+	rts
+
+text
+	dw $0400
+	dw $0480
+	dw $0500
+	dw $0580
+	dw $0600
+	dw $0680
+	dw $0700
+	dw $0780
+	dw $0428
+	dw $04a8
+	dw $0528
+	dw $05a8
+	dw $0628
+	dw $06a8
+	dw $0728
+	dw $07a8
+	dw $0450
+	dw $04d0
+	dw $0550
+	dw $05d0
+	dw $0650
+	dw $06d0
+	dw $0750
+	dw $07d0
+
+*box
+*	asc " ______________________________________ "
+*	asc da," Terminal ",'                            ',df
+*	db $da
+*	ds 38,$cc
+*	db $df
+
+
+*	asc da," Select: ",c8,df,ca,cb,"  Cancel: Esc Save: ",cd,df
+*	asc " "
+*	ds 38,$cc
+*	asc " "
+
+
+	sav vt100.cda.L
\ No newline at end of file
diff --git a/vt100.link.S b/vt100.link.S
index b96ce8e..1211750 100644
--- a/vt100.link.S
+++ b/vt100.link.S
@@ -15,6 +15,7 @@
 	asm vt100.modem.S
 	asm vt100.key.S
 	asm vt100.beep.S
+	asm vt100.cda.S
 
 
 *	lnk boot.S
@@ -34,6 +35,7 @@
 	lnk vt100.modem.L
 	lnk vt100.key.L
 	lnk vt100.beep.L
+	lnk vt100.cda.L
 
 	typ $ff
 	sav vt100.sys
diff --git a/vt100.main.S b/vt100.main.S
index 80164b2..fa185da 100644
--- a/vt100.main.S
+++ b/vt100.main.S
@@ -16,6 +16,7 @@
 	ext erase_screen
 	ext init_tabs
 	ext init_audio
+	ext init_cda
 
 main	debug main
 
@@ -98,6 +99,7 @@ init
 	jsr init_modem
 	jsr init_tabs
 	jsr init_audio
+	jsr init_cda
 	rts