Appendix ( bootsector code to initialize hardware ) 

; Multi Atari Boot code.
; If you have done an ST demo, use that boot to run it on these machines:
;
; ST, STe, Mega-ST,TT,Falcon,CT60
;
; More info:
; http://leonard.oxg.free.fr/articles/multi_atari/multi_atari.html





start sf $1fe.w
move.l $5a0.w,d0
beq noCookie
move.l d0,a0
.loop: move.l (a0)+,d0
beq noCookie
cmp.l #'_MCH',d0
beq.s .find
cmp.l #'CT60',d0
bne.s .skip

; CT60, switch off the cache
pea (a0)

lea bCT60(pc),a0
st (a0)

clr.w -(a7) ; param = 0 ( switch off all caches )
move.w #5,-(a7) ; opcode
move.w #160,-(a7)
trap #14
addq.w #6,a7
move.l (a7)+,a0
.skip:
addq.w #4,a0
bra.s .loop

.find: move.w (a0)+,d7
beq noCookie ; STF
move.b d7,$1fe.w

cmpi.w #1,d7
bne.s .noSTE
btst.b #4,1(a0)
beq.s .noMegaSTE
clr.b $ffff8e21.w ; 8Mhz MegaSTE

.noMegaSTE: 
bra noCookie

.noSTE:
; here TT or FALCON

; Always switch off the cache on these machines.
move.b bCT60(pc),d0
bne.s .noMovec

moveq #0,d0
dc.l $4e7b0002 ; movec d0,cacr ; switch off cache
.noMovec:

cmpi.w #3,d7
bne.s noCookie

; Here FALCON
move.w #$59,-(a7) ;check monitortype (falcon)
trap #14
addq.l #2,a7
lea rgb50(pc),a0
subq.w #1,d0
beq.s .setRegs
subq.w #2,d0
beq.s .setRegs
lea vga50(pc),a0

.setRegs:
move.l (a0)+,$ffff8282.w
move.l (a0)+,$ffff8286.w
move.l (a0)+,$ffff828a.w
move.l (a0)+,$ffff82a2.w
move.l (a0)+,$ffff82a6.w
move.l (a0)+,$ffff82aa.w
move.w (a0)+,$ffff820a.w
move.w (a0)+,$ffff82c0.w
move.w (a0)+,$ffff8266.w
clr.b $ffff8260.w
move.w (a0)+,$ffff82c2.w
move.w (a0)+,$ffff8210.w

noCookie:

; Set res for all machines exept falcon or ct60
cmpi.b #3,$1fe.w
beq letsGo

clr.w -(a7) ;set stlow (st/tt)
moveq #-1,d0
move.l d0,-(a7)
move.l d0,-(a7)
move.w #5,-(a7)
trap #14
lea 12(a7),a7

cmpi.b #2,$1fe.w ; enough in case of TT
beq.s letsGo

move.w $468.w,d0
.vsync: cmp.w $468.w,d0
beq.s .vsync

move.b #2,$ffff820a.w
clr.b $ffff8260.w

;---------------------------------------------------------------------
letsGo: 

; load your kernel, or whatever you want here !


;---------------------------------------------------------------------

vga50: dc.l $170011
dc.l $2020E
dc.l $D0012
dc.l $4EB04D1
dc.l $3F00F5
dc.l $41504E7
dc.w $0200
dc.w $186
dc.w $0
dc.w $5
dc.w $50

rgb50: dc.l $300027
dc.l $70229
dc.l $1e002a
dc.l $2710265
dc.l $2f0081
dc.l $211026b
dc.w $0200
dc.w $185
dc.w $0
dc.w $0
dc.w $50

bCT60: dc.b 0
even