ca65 V2.17 - Git 582aa41
Main file   : keywrite.ca65
Current file: keywrite.ca65

000000r 1               ;
000000r 1               ; ACORN System 1 Applications: Keywrite
000000r 1               ;
000000r 1               ; From the Acorn Teletext Board Technical Manual
000000r 1               ;
000000r 1               ; (Chris Oddy January 2022)
000000r 1               ;
000000r 1               ; entry point $0280
000000r 1               ;
000000r 1               		.setcpu			"6502"
000000r 1               		.listbytes		unlimited
000000r 1               ;
000000r 1               TEMP	:=		$26
000000r 1               CHATS	:=		$0300		; character to screen
000000r 1               DISPLAY	:=		$FE0C		; scan the display
000000r 1               RESTART	:=		$FF04		; Monitor reentry point
000000r 1               ;
000000r 1               		.org			$0280
000280  1               ;
000280  1  20 0C FE     KEYWRT:	jsr		DISPLAY
000283  1  90 0E        		bcc		SEND		; hex key ?
000285  1  29 07        CONTRL:	and		#$07
000287  1  F0 1B        		beq		RET
000289  1  A8           		tay					; look up control keys in table
00028A  1  B9 A6 02     		lda		TABLE-1,y
00028D  1  20 00 03     SENDER:	jsr		CHATS
000290  1  4C 80 02     		jmp		KEYWRT
000293  1  0A           SEND:	asl		A
000294  1  0A           		asl		A
000295  1  0A           		asl		A
000296  1  0A           		asl		A
000297  1  85 26        		sta		TEMP
000299  1  20 0C FE     		jsr		DISPLAY
00029C  1  B0 E7        		bcs		CONTRL
00029E  1  05 26        		ora		TEMP		; mix in low digit
0002A0  1  09 80        		ora		#$80		; fool control character check
0002A2  1  30 E9        		bmi		SENDER		; forced branch to SENDER
0002A4  1  4C 04 FF     RET:	jmp		RESTART		; M key returns to MONITOR
0002A7  1  20           TABLE:	.byte	$20			; G key gives space bar
0002A8  1  20           		.byte	$20			; P key gives space bar
0002A9  1  20           		.byte	$20			; S key gives space bar
0002AA  1  0A           		.byte	$0A			; L key gives linefeed
0002AB  1  0C           		.byte	$0C			; R key gives formfeed
0002AC  1  7F           		.byte	$7F			; <up> key gives delete
0002AD  1  0D           		.byte	$0D			; <down> key gives carriage return
0002AD  1