From 52caf07ad4e5edaad6866fbd7cf865d119eacd01 Mon Sep 17 00:00:00 2001 From: cpg Date: Sun, 3 Dec 2000 23:39:22 +0000 Subject: [PATCH] Basic-like GRAPHICS function; not yet implemented; provides the "graphics memory used" constructor git-svn-id: svn://svn.cc65.org/cc65/trunk@541 b7a2c559-68d2-44c3-8de9-860c34a00d81 --- libsrc/atari/graphics.s | 98 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 libsrc/atari/graphics.s diff --git a/libsrc/atari/graphics.s b/libsrc/atari/graphics.s new file mode 100644 index 000000000..2b82207e5 --- /dev/null +++ b/libsrc/atari/graphics.s @@ -0,0 +1,98 @@ +; +; Christian Groessler, December 2000 +; +; this file provides an equivalent to the BASIC GRAPHICS function +; +; void __fastcall__ graphics(unsigned char mode); + + .export _graphics + .constructor scr_memtop,28 + + .import __graphmode_used + + .include "atari.inc" + + .code + + +.proc _graphics + + rts ; not implemented yet! + +.endproc + + +; calc. upper memory limit to use + +.proc scr_memtop + + lda __graphmode_used + beq ignore ; mode 0 doesn't need adjustment + cmp #32 + bcs ignore ; invalid value + + asl a + tay + lda APPMHI + sec + sbc grmemusage,y + sta APPMHI + lda APPMHI+1 + sbc grmemusage+1,y + sta APPMHI+1 +ignore: rts + +.endproc + + .rodata + +; memory usage of the different graphics modes (0-31) +; values < 0 of "bytes needed" are mappped to 0 +; bytes needed ; mode ; val. of MEMTOP +grmemusage: + .word 0 ; 0 ; 39967 + .word 0 ;-318 ; 1 ; 40285 + .word 0 ;-568 ; 2 ; 40535 + .word 0 ;-558 ; 3 ; 40525 + .word 0 ;-298 ; 4 ; 40265 + .word 182 ; 5 ; 39785 + .word 1182 ; 6 ; 38785 + .word 3198 ; 7 ; 36769 + .word 7120 ; 8 ; 32847 + .word 7146 ; 9 ; 32821 + .word 7146 ; 10 ; 32821 + .word 7146 ; 11 ; 32821 + .word 162 ; 12 ; 39805 + .word 0 ;-328 ; 13 ; 40295 + .word 3278 ; 14 ; 36689 + .word 7120 ; 15 ; 32847 + .word 0 ; 16 ; 39967 + .word 0 ;-320 ; 17 ; 40287 + .word 0 ;-572 ; 18 ; 40539 + .word 0 ;-560 ; 19 ; 40527 + .word 0 ;-296 ; 20 ; 40263 + .word 184 ; 21 ; 39783 + .word 1192 ; 22 ; 38775 + .word 3208 ; 23 ; 36759 + .word 7146 ; 24 ; 32821 + .word 7146 ; 25 ; 32821 + .word 7146 ; 26 ; 32821 + .word 7146 ; 27 ; 32821 + .word 160 ; 28 ; 39807 + .word 0 ;-332 ; 29 ; 40299 + .word 3304 ; 30 ; 36663 + .word 7146 ; 31 ; 32821 + +; the program used to get these values (Atari BASIC): +; 100 FILE=0 +; 110 IF FILE=1 THEN OPEN #1,8,0,"D:FREEMEM.OUT" +; 120 IF FILE<>1 THEN OPEN #1,8,0,"E:" +; 200 DIM G(32) +; 210 FOR I=0 TO 32:GRAPHICS I:GOSUB 1000:G(I)=VAL:NEXT I +; 220 GRAPHICS 0 +; 230 FOR I=0 TO 31:PRINT #1;I;":",G(I);" - ";G(0)-G(I):NEXT I +; 240 CLOSE #1 +; 999 END +; 1000 VAL=PEEK(741)+256*PEEK(742) +; 1010 RETURN + -- 2.39.5