שתשת*********************************************************** * $VER: StartUp_S 3.4 * * This is my TakeSystem and RestoreSystem routines that I now use * in all my demos. I am spreading them in hopes to get rid of the * crapy coding practices that people have had since the C64 days. * I'd like to thank Comrade J for his excellent "howtocode" files. * A lot of the stuff here is based on his words of wisdom. :^). Anyway, * these routines, as of version 3.4, handle the following: * Getting the VBR. * Saving DMACON. * Saving Intena. * Saving and reseting WB view modes. * Owning/Disowning the blitter. * Pal/Ntsc/AGA modes. * Killing multitasking. * Killing interrupts. * Fixed equates for case sensitive assemblers. * Easy to make 100% PC relative. * * Feel free to cut and paste to fit your code (i.e. put the data and bss in * your data and bss sections.), but please leave the CODE intact! * If you have any questions/comments/suggestions, PLEASE contact me at * either: * idr@rigel.cs.pdx.edu (internet) * - or - * Epsilon * P.O.B. 1914 * Beaverton, OR 97075-1914 * U.S.A. * * Many of you may not like the fact that I use includes and system calls, * I know I don't :), but it is the ONLY SAFE WAY TO TAKE THE SYSTEM! To * insure that your demo will work on any system, it's what you have to do. * *********************************************************** * Includes *********************************************************** incdir "DevpacAm:include/" include "exec/exec_lib.i" include "exec/execbase.i" include "graphics/gfxbase.i" include "graphics/graphics_lib.i" include "hardware/custom.i" *********************************************************** * Other Macros *********************************************************** CALL MACRO jsr _LVO\1(a6) ENDM *********************************************************** * Other Structs *********************************************************** rsreset gfx_base rs.l 1 ; pointer to graphics base OldView rs.l 1 ; old Work Bench view addr. VectorBase: rs.l 1 ; pointer to the Vector Base OldDMACon: rs.w 1 ; old dmacon bits OldINTEna: rs.w 1 ; old intena bits ntsc: rs.b 1 ; 0 = pal, 1 = ntsc AGA: rs.b 1 ; 0 = ESC/standard, 1 = AGA SYS_SIZE rs.b 0 ; size of the struct *********************************************************** section TheCode,code TakeSystem: movea.l 4.w,a6 ; exec base lea $dff002,a5 ; custom chip base + 2 lea SystemSave,a4 ; where to save everything lea GraphicsName,a1 ; "graphics.library" moveq #0,d0 ; any version CALL OpenLibrary ; open it. move.l d0,gfx_base(a4) ; save pointer to gfx base beq.b .erexit ; if we got a NULL, then exit movea.l d0,a6 ; for later callls... move.l gb_ActiView(a6),OldView(a4) ; save old view move.w #0,a1 ; clears full long-word CALL LoadView ; Open a NULL view (resets display ; on any Amiga) CALL WaitTOF ; Wait twice so that an interlace CALL WaitTOF ; display can reset. CALL OwnBlitter ; take over the blitter and... CALL WaitBlit ; wait for it to finish so we ; safely use it as we please. movea.l 4.w,a6 ; exec base CALL Forbid ; kill multitasking cmpi.b #50,VBlankFrequency(a6) ; is vblank rate pal? beq.b .pal ; yup. st ntsc(a4) ; set NTSC flag. .pal: move.w $7c-2(a5),d0 ; AGA register... cmpi.b #$f8,d0 ; are we AGA? bne.b .not_aga ; nope. st AGA(a4) ; set the AGA flag. move.w #0,$1fc-2(a5) ; reset AGA sprites to normal mode .not_aga: bsr.b GetVBR ; get the vector base pointer move.l d0,VectorBase(a4) ; save it for later. move.w dmaconr-2(a5),d0 ; old DMACON bits ori.w #$8000,d0 ; or it set bit for restore move.w d0,OldDMACon(a4); save it move.w intenar-2(a5),d0 ; old INTEna bits ori.w #$c000,d0 ; or it set bit for restore move.w d0,OldINTEna(a4); save it move.l #$7fff7fff,intena-2(a5) ; kill all ints move.w #$7fff,dmacon-2(a5) ; kill all dma moveq #0,d0 ; return no error code rts .erexit: moveq #-1,d0 ; error, don't run demo. rts *********************************************************** RestoreSystem: lea $dff002,a5 ; custom chip base + 2 lea SystemSave,a4 ; where it's all at ; You must do these in this order or you're asking for trouble! move.l #$7fff7fff,intena-2(a5) ; kill all ints move.w #$7fff,dmacon-2(a5) ; kill all dma move.w OldDMACon(a4),dmacon-2(a5) ; restore old dma bits move.w OldINTEna(a4),intena-2(a5) ; restore old int bits movea.l OldView(a4),a1 ; old Work Bench view movea.l gfx_base(a4),a6 ; gfx base CALL LoadView ; Restore the view CALL DisownBlitter ; give blitter back to the system. move.l gb_copinit(a6),$80-2(a5) ; restore system clist movea.l a6,a1 movea.l 4.w,a6 ; exec base CALL CloseLibrary ; there is no call to Permit() because it is implied by the return ; to AmigaDOS! :^) rts *********************************************************** * This function provides a method of obtaining a pointer to the base of the * interrupt vector table on all Amigas. After getting this pointer, use * the vector address as an offset. For example, to install a level three * interrupt you would do the following: * * bsr _GetVBR * move.l d0,a0 * move.l $6c(a0),OldIntSave * move.l #MyIntCode,$6c(a0) * *********************************************************** * Inputs: none * Output: d0 contains vbr. GetVBR: move.l a5,-(sp) ; save it. moveq #0,d0 ; clear movea.l 4.w,a6 ; exec base btst.b #AFB_68010,AttnFlags+1(a6); are we at least a 68010? beq.b .1 ; nope. lea.l vbr_exception(pc),a5 ; addr of function to get VBR CALL Supervisor ; supervisor state .1: move.l (sp)+,a5 ; restore it. rts ; return vbr_exception: ; movec vbr,Xn is a priv. instr. You must be supervisor to execute! movec vbr,d0 ; many assemblers don't know the VBR, if yours doesn't, then use this ; line instead. ; dc.l $4e7a0801 rte ; back to user state code *********************************************************** section TheData,data GraphicsName: GRAFNAME ; name of gfx library EVEN *********************************************************** section OldPointers_and_such,bss SystemSave: ds.b SYS_SIZE