Mercurial > hg > Members > kono > nitros9-code
view level1/modules/boot_1773.asm @ 249:30655a7845f7
Cut delay in half
| author | boisy |
|---|---|
| date | Sat, 20 Jul 2002 04:02:33 +0000 |
| parents | 3d2fa54fe8fb |
| children | bb618bed0bdc |
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******************************************************************** * Boot - WD1773 Boot for OS-9 * * $Id$ * * Ed. Comments Who YY/MM/DD * ------------------------------------------------------------------ * 4 From Tandy OS-9 Level Two VR 02.00.01 and * modified to work properly under OS-9 Level One nam Boot ttl os9 system module * Disassembled 98/08/23 21:21:26 by Disasm v1.6 (C) 1988 by RML ifp1 use defsfile use rbfdefs endc * Step Rate: * $00 = 6ms * $01 = * $02 = * $03 = 30ms STEP equ $00 tylg set Systm+Objct atrv set ReEnt+rev rev set $01 edition set 4 mod eom,name,tylg,atrv,start,size u0000 rmb 2 u0002 rmb 2 u0004 rmb 1 u0005 rmb 1 u0006 rmb 1 u0007 rmb 1 u0008 rmb 1 u0009 rmb 1 size equ . name fcs /Boot/ fcb edition * First, we make a stack... start clra ldb #size MakeStak pshs a decb bne MakeStak tfr s,u ldx #DPort+8 lda #$D0 sta ,x lbsr L01A7 lda ,x lda #$FF sta u0004,u leax >NMIRtn,pcr ifgt Level-1 stx <D.NMI lda #$09 else stx >$010A lda #$7E sta >$0109 lda #$08 endc sta >DPort * delay loop ifgt Level-1 ldd #$C350 else ldd #$61A8 endc L003A nop nop subd #$0001 bne L003A * search for a free page (to use as a 256 byte disk buffer) pshs u,y,x,b,a ldd #$0001 os9 F$SRqMem bcs L00AA tfr u,d ldu $06,s std u0002,u clrb * go get LSN0 ldx #$0000 bsr L00C4 bcs L00AA * get bootfile size from LSN0 and allocate memory for it ldd DD.TOT+1,y std u0007,u lda <DD.FMT,y sta u0005,u anda #$01 sta u0008,u lda DD.TKS,y sta u0006,u ldd <DD.BSZ,y std ,s ldx <DD.BT+1,y pshs x ldd #256 ldu u0002,u os9 F$SRtMem ldd $02,s ifgt Level-1 os9 F$BtMem else os9 F$SRqMem endc puls x bcs L00AA stu $02,s ldu $06,s ldd $02,s std u0002,u ldd ,s beq L00A3 * this loop reads a sector at a time from the bootfile L0091 pshs x,b,a clrb bsr L00C4 bcs L00A8 puls x,b,a inc u0002,u leax 1,x subd #256 bhi L0091 L00A3 clrb puls b,a bra L00AC L00A8 leas $04,s L00AA leas $02,s L00AC ifgt Level-1 sta >$FFD9 endc puls u,y,x leas size,s rts L00B4 lda #$29 sta ,u clr u0004,u lda #$05 lbsr L016D ldb #STEP lbra L0192 L00C4 lda #$91 cmpx #$0000 bne L00DC bsr L00DC bcs L00D3 ldy u0002,u clrb L00D3 rts L00D4 bcc L00DC pshs x,b,a bsr L00B4 puls x,b,a L00DC pshs x,b,a bsr L00E7 puls x,b,a bcc L00D3 lsra bne L00D4 L00E7 bsr L0139 bcs L00D3 ldx u0002,u orcc #IntMasks pshs y ldy #$FFFF ldb #$80 stb >DPort+8 ldb ,u orb #$30 tst u0009,u beq L0104 orb #$40 L0104 stb >DPort lbsr L01A7 orb #$80 lda #$02 L010E bita >DPort+8 bne L0120 leay -$01,y bne L010E lda ,u sta >DPort puls y bra L0135 L0120 lda >DPort+$B sta ,x+ stb >DPort bra L0120 NMIRtn leas size+2,s puls y ldb >DPort+8 bitb #$04 beq L018C L0135 comb ldb #E$Read rts L0139 lda #$09 sta ,u clr u0009,u tfr x,d cmpd #$0000 beq L0169 clr ,-s tst u0008,u beq L015F bra L0155 L014F com u0009,u bne L0155 inc ,s L0155 subb u0006,u sbca #$00 bcc L014F bra L0165 L015D inc ,s L015F subb u0006,u sbca #$00 bcc L015D L0165 addb #18 puls a L0169 incb stb >DPort+$A L016D ldb u0004,u stb >DPort+9 cmpa u0004,u beq L018A sta u0004,u sta >DPort+$B ldb #$10+STEP bsr L0192 pshs x ldx #$222E L0184 leax -1,x bne L0184 puls x L018A clrb rts L018C bitb #$98 bne L0135 clrb rts L0192 bsr L01A5 L0194 ldb >DPort+$8 bitb #$01 bne L0194 rts L019C lda ,u sta >DPort stb >DPort+$8 rts L01A5 bsr L019C L01A7 lbsr L01AA L01AA lbsr L01AD L01AD rts ifgt Level-1 rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts rts endc emod eom equ * end