atari5200 update: simple conio "hello world" works now

2014-04-25 03:02:44 +02:00
parent ec417c0dc5
commit 92b32d7d0e
7 changed files with 252 additions and 14 deletions
--- a/libsrc/atari5200/conioscreen.s
+++ b/libsrc/atari5200/conioscreen.s
@@ -0,0 +1,67 @@
+
+                .include "atari5200.inc"
+
+SCREEN_BUF_SIZE	=	20 * 24
+SCREEN_BUF	=	$4000 - SCREEN_BUF_SIZE
+
+                .code
+                .export screen_setup_20x24
+
+screen_setup_20x24:
+
+		; initialize SAVMSC
+		lda	#<SCREEN_BUF
+		sta	SAVMSC
+		lda	#>SCREEN_BUF
+		sta	SAVMSC+1
+
+		; initialize cursor position
+		lda	#0
+		sta	COLCRS_5200
+		sta	ROWCRS_5200
+
+		; clear screen buffer
+		ldy	#<(SCREEN_BUF_SIZE-1)
+		ldx	#>(SCREEN_BUF_SIZE-1)
+clrscr:		sta	(SAVMSC),y
+		dey
+		cpy	#$FF
+		bne	clrscr
+		dex
+		cpx	#$FF
+		bne	clrscr
+
+		; set display list
+
+		lda	#<dlist
+		sta	SDLSTL
+		lda	#>dlist
+		sta	SDLSTH
+
+		rts
+
+
+                .segment "RODATA"
+
+; display list for 20x24 text mode
+
+dlist:          .repeat 3
+                .byte   DL_BLK8
+                .endrepeat
+                
+                .byte   DL_CHR20x8x2 | DL_LMS
+                .word   SCREEN_BUF
+
+                .repeat 23
+                .byte   DL_CHR20x8x2
+                .endrepeat
+
+                .byte  DL_JVB
+                .word   dlist
+
+; end of display list
+
+.assert ((* >> 10) = (dlist >> 10)), error, "Display list crosses 1K boundary"
+
+
+                .end