itty-bitty-vtty/vt100.key.S

	lst off
	rel
	xc
	xc

	tbx on

	use vt.equ
	use apple2gs.equ
	use debug

	mx %11

*	ext dispatch
	ext write_modem


kmShift		equ %0000_0001
kmControl	equ %0000_0010
kmCapsLock	equ %0000_0100
kmRepeat	equ %0000_1000
kmKeypad	equ %0001_0000
kmUpdateMod	equ %0010_0000
kmOption	equ %0100_0000
kmCommand	equ %1000_0000


*
* The vt100 has a delete key and a backspace key.
* delete sends 0x7f.  backspace sends 0x08.
* stty is general set so 0x7f is the erase character.
* termcaps generally claim 0x08 is the backspace character.
*
* emacs, by default, thinks 0x08 ( ^H ) means you want help.
*
* so, backspace will send 0x7f.  control-H or command-backspace
* will send 0x08. 

*
* TODO - keys
* command-L -> local/online mode?
* command-Q -> quit
* command-K -> clear screen?
* command-R -> reset settings
*


dispatch
	jmp write_modem

keypress ent
	debug keypress
	lda KBD
	bmi :key
:rts	rts
:key
	and #$7f
	sta key
	lda KEYMOD
	sta mod
	sta KEYSTROBE

* if DECARM is clear, skip repeat characters.
*
* a REAL vt100 will never auto-repeat ESC, TAB, RETURN, or if Control is also pressed. 
*
	bit DECARM
	bmi :arm
	bit #kmRepeat
	bne :rts
:arm


	bit #kmOption!kmCommand
	bne command

	bit #kmKeypad
	jne keypad
	bit #kmControl
	bne :ctrl

	lda key
	cmp #' '
	bcs :notctrl

* control char w/o control bit.
* ie, arrow key / return / tab
* no cmp / sbc needed
	asl
	tax
	lsr ; restore
	jmp (special,x)

:ctrl
	lda key
	and #$1f ; control-space should generate 0, not $20.
	bra :send

:notctrl
*	cmp #$7f ; delete - special case 
*	bne :send
*	lda #$08
:send	jmp dispatch

command ; or option

* apple-return -> linefeed
* apple-backspace -> delete
	

	lda key
	cmp #$7f
	beq :bs
	cmp #$0d
	beq :lf

	cmp #'a'
	bcc :0
	cmp #'z'+1
	bcs :0

	and #$df ; ~ $20

:0
	cmp #:MIN
	blt :rts
	cmp #:MAX+1
	bcs :rts
	sec
	sbc #:MIN
	asl
	tax
	jmp (:table,x)

:rts	rts


:bs	lda #$08
	jmp dispatch ; 
:lf	lda #$0a
	jmp dispatch

	ext enable_modem,disable_modem
:local
	bit LOCAL
	bmi :online
	lda #$80
	sta LOCAL
	jmp disable_modem

:online
	stz LOCAL
	jmp enable_modem

:quit
	ext quit
	jmp quit
	rts

:reset
* TODO
	rts

:clear
* TODO
	rts


:MIN	equ 49
:MAX	equ 82

:table
	dw pf1		; 1
	dw pf2		; 2
	dw pf3		; 3
	dw pf4		; 4
	dw :rts		; 5
	dw :rts		; 6
	dw :rts		; 7
	dw :rts		; 8
	dw :rts		; 9
	dw :rts		; :
	dw :rts		; ;
	dw :rts		; <
	dw :rts		; =
	dw :rts		; >
	dw :rts		; ?
	dw :rts		; @
	dw :rts		; A
	dw :rts		; B
	dw :rts		; C
	dw :rts		; D
	dw :rts		; E
	dw :rts		; F
	dw :rts		; G
	dw :rts		; H
	dw :rts		; I
	dw :rts		; J
	dw :clear	; K
	dw :local	; L
	dw :rts		; M
	dw :rts		; N
	dw :rts		; O
	dw :rts		; P
	dw :quit	; Q
	dw :reset	; R



keypad

	lda key
	cmp #:MIN
	blt :rts
	cmp #:MAX+1
	bcs :other
	sec
	sbc #:MIN
	asl
	tax
	jmp (:table,x)

:other

* keypad delete key ($75 aka 'u') will send as backspace ($08)
*
	cmp #'u'
	bne :rts
	lda #$08
	jmp dispatch
	

:rts	rts

:MIN	equ 13
:MAX	equ 61
:table
	dw enter	; ^M Enter -> \r, ESC ? M
	dw :rts		; ^N
	dw :rts		; ^O
	dw :rts		; ^P
	dw :rts		; ^Q
	dw :rts		; ^R
	dw :rts		; ^S
	dw :rts		; ^T
	dw :rts		; ^U
	dw :rts		; ^V
	dw :rts		; ^W
	dw :rts		; ^X
	dw :rts		; ^Y
	dw :rts		; ^Z
	dw pf1		; ^[ PF1 -> ESC P
	dw :rts		; ^\
	dw :rts		; ^]
	dw :rts		; ^^
	dw :rts		; ^_
	dw :rts		;  
	dw :rts		; !
	dw :rts		; "
	dw :rts		; #
	dw :rts		; $
	dw :rts		; %
	dw :rts		; &
	dw :rts		; '
	dw :rts		; (
	dw :rts		; )
	dw pf4		; *
	dw comma	; +
	dw :rts		; ,
	dw dash		; -
	dw dot		; .
	dw pf3		; / PF3 -> ESC R
	dw digit	; 0
	dw digit	; 1
	dw digit	; 2
	dw digit	; 3
	dw digit	; 4
	dw digit	; 5
	dw digit	; 6
	dw digit	; 7
	dw digit	; 8
	dw digit	; 9
	dw :rts		; :
	dw :rts		; ;
	dw :rts		; <
	dw pf2		; = PF2 -> ESC Q


enter
	bit DECKPAM
	bmi :alt
	brl cr
:alt
	jmp ?O

comma
* iigs keyboard is a +
	lda #','
	sta key
	bit DECKPAM
	bmi :alt
	jmp dispatch
:alt
	jmp ?O
dot
	lda key
	bit DECKPAM
	bmi :alt
	jmp dispatch
:alt
	jmp ?O

dash
	lda key
	bit DECKPAM
	bmi :alt
	jmp dispatch
:alt
	jmp ?O

digit
	lda key
	bit DECKPAM
	bmi :alt
	jmp dispatch
:alt

*	jmp ?O
* drop through

?O
* send ESC ? key if vt52, ESC O key if vt100

	lda #ESC
	jsr dispatch
	bit DECANM
	bpl :vt52
	lda #'O'
	jsr dispatch
	lda key
	ora #$40
	jmp dispatch
:vt52
	lda #'?'
	jsr dispatch
	lda key
	ora #$40
	jmp dispatch


pf1
	lda #'P'
	sta key
	bra pf
pf2
	lda #'Q'
	sta key
	bra pf
pf3
	lda #'R'
	sta key
	bra pf
pf4
	lda #'S'
	sta key
pf
	lda #ESC
	jsr dispatch
	bit DECANM
	bpl :vt52
	lda #'O'
	jsr dispatch
:vt52	lda key
	jmp dispatch


special
	dw dispatch		; ^@
	dw dispatch		; ^A
	dw dispatch		; ^B
	dw dispatch		; ^C
	dw dispatch		; ^D
	dw dispatch		; ^E
	dw dispatch		; ^F
	dw dispatch		; ^G
	dw left			; ^H
	dw dispatch		; ^I - tab
	dw down			; ^J
	dw up			; ^K
	dw dispatch		; ^L
	dw cr			; ^M
	dw dispatch		; ^N
	dw dispatch		; ^O
	dw dispatch		; ^P
	dw dispatch		; ^Q
	dw dispatch		; ^R
	dw dispatch		; ^S
	dw dispatch		; ^T
	dw right		; ^U
	dw dispatch		; ^V
	dw dispatch		; ^W
	dw dispatch		; ^X
	dw dispatch		; ^Y
	dw dispatch		; ^Z
	dw dispatch		; ^[
	dw dispatch		; ^\
	dw dispatch		; ^]
	dw dispatch		; ^^
	dw dispatch		; ^_



cr
* Return sends CR or CR + LF (LNM)
	bit LNM
	bmi :crlf
	lda #$0d
	jmp dispatch

:crlf
	lda #$0d
	jsr dispatch
	lda #$0a
	jmp dispatch


left
	lda #'D'
	bra arrow
right
	lda #'C'
	bra arrow
up
	lda #'A'
	bra arrow
down
	lda #'B'
* drop through
arrow
* actual character generated depends on DECANM and DECCKM

	sta key
	lda #ESC
	jsr dispatch

	bit DECANM
	bpl :vt52
	bit DECCKM
	bmi :cursor

	lda #'['
	jsr dispatch
	lda key
	jmp dispatch

:cursor
	lda #'O'
	jsr dispatch
* drop through.
:vt52
	lda key
	jmp dispatch

	sav vt100.key.L