diff --git a/ATALoad.a b/ATALoad.a
index 9e889ea..c197f4e 100644
--- a/ATALoad.a
+++ b/ATALoad.a
@@ -1,6 +1,5 @@
 ; Asm ATALoad.a -o ATALoad.a.o; DumpObj ATALoad.a.o > ATALoad.dmp
 ; The python script does the rest.
-; This is messy and brittle. I got very, very sick of it!
 
     MAIN
     MACHINE MC68030
@@ -12,6 +11,11 @@
     bsr.s   OriginalFunc    ; ... and call the function
     add.l   #$C,sp          ; pop those copied arguments, we don't need them
 
+;    move.l  d0,-(sp)
+;    move.l  d0,a0
+;    bsr     PrintHex
+;    move.l  (sp)+,d0
+
     cmp.l   #$FFFFDB93,d0   ; ATANoDriverErr -> try our method
     beq.s   NewFunc
     cmp.l   #$FFFFDB92,d0   ; ATANoDDMErr -> try our method
@@ -21,247 +25,68 @@
 
 OriginalFunc
     string  asis
-    dc.b    'Nsrt'          ; placeholder for script to insert the clobbered LINK instruction
-    bra     *+2+'ID'        ; placeholder for script to jump to remainder of original function
-
-
-
-var_regs                  equ -$4FA
-
-ataPB                     equ -$4DA ; to
-ataPBQType                equ -$4D6
-ataPBVers                 equ -$4D4
-ataPBReserved2            equ -$4CE
-ataPBFunctionCode         equ -$4C8
-ataPBIOSpeed              equ -$4C7
-ataPBFlags                equ -$4C6
-ataPBDeviceID             equ -$4C2
-ataPBTimeOut              equ -$4BE
-ataPBState                equ -$4B2
-
-; common part of PB ends at offset $30 = -$4AA
-; this part below is a bit tricky...
-
-ataPB34                  equ -$4A6 ; 34
-ataPB38                  equ -$4A2 ; 38
-ataPB3C                  equ -$49E ; 3c
-ataPB40                  equ -$49A ; 40
-
-; -492...-48A = "task file"
-
-ataPBTaskFile_ataTFCount    equ -$491
-ataPBTaskFile_ataTFSDH      equ -$48C
-ataPBTaskFile_ataTFCommand  equ -$48B
-
-; entire PB ends at offset $30 = -$4AA
-
-; max possible PB size ends at $B8 = -$422
-
-var_bstruct_0   equ -$422
-var_bstruct_2   equ -$420
-var_bstruct_4   equ -$41E
-var_bstruct_6   equ -$41C
-
-var_ddmidx      equ -$41A
-var_drvrcnt     equ -$418
-var_arg2        equ -$40E
-var_ddmptr      equ -$40C
-
-var_buf1        equ -$408
-var_buf2        equ -$208
-
-var_flags       equ -8
-var_4           equ -4
-
-arg_dev         equ  8
-arg_ddtype      equ  $C ; a long
-arg_romdrvr     equ  $10
+    dc.b    'Nsrt'          ; LINKER SCRIPT
+    bra     *+2+'ID'        ; LINKER SCRIPT
 
 
 NewFunc
-                link    a6,#-$4DA
-                movem.l d3-d7/a2-a4,-(sp)
+    link    a6,#-4
+    movem.l d5,-4(a6)
+
+    ; 16(a6).L = !AfterSystemStartupTime
+    ; 12(a6).L = $0701, the DDMap ID for a Mac driver
+    ;  8(a6).L = device ID (i.e. devNum<<8 | busNum)
+
+;    move.l  16(a6),a0
+;    bsr     PrintHex
+;    move.l  12(a6),a0
+;    bsr     PrintHex
+;    move.l  8(a6),a0
+;    bsr     PrintHex
+
+    cmp.w   #$0701,12+2(a6)
+    bne.s   @fail
+
+    move.l  #'Size',d0          ; LINKER SCRIPT
+    dc.w    $A51E               ; _NewPtrSys
+    tst.l   A0
+    beq.s   @fail
+
+    move.l  a0,a1
+    lea     *+2+'At',a0         ; LINKER SCRIPT
+    move.l  #'Size',d0          ; LINKER SCRIPT
+    dc.w    $A02E               ; _BlockMove
+
+    move.l  8(a6),d5            ; put device number in this byte
+    and.l   #$0000FF00,d5
+
+    move.l  8(a6),d0            ; put bus number in this byte
+    swap    d0
+    and.l   #$00FF0000,d0
+    or.l    d0,d5
+
+    tst.b   16+3(a6)
+    bne.s   @rom
+    bset.l  #31,d5              ; kAfterSystemStartupTime
+@rom
+
+    jsr     8(a0)               ; ATAMgr v2 entry point
+                                ; never mind the spec, only set d5
+
+;    move.l  d0,a0
+;    bsr     PrintHex
+
+    bra.s   @return
+
+@fail
+    move.l  #$FFFFDB93,d0
+@return
+    movem.l -4(a6),d5
+    unlk    a6
+    rts
 
 
-; Wipe the stack frame to be safe
-                lea     -$4DA(A6),A0
-@lup            clr.w   (A0)+
-                cmp.l   A0,A6
-                bne.s   @lup
-
-; Check that we are asked for an ATA driver
-                cmp.l   #$00000701,arg_ddtype(a6)   ; kDriverTypeMacATA
-                bne     itr_fail
-
-; Load the actual working driver
-                move.w  #$FFFF,$B9E         ; temp ROMMapInsert
-                move.l  #'DRVR',-(SP)
-                move.w  #53,-(SP)           ; .ATADisk
-                dc.w    $A9A0
-                movea.l (SP)+,A2
-                tst.l   A2
-                beq     itr_fail
-                movea.l (A2),A2
-
-; Set pointers to the 512-byte scratch buffer and the param block
-                lea     var_buf1(a6),a3
-                lea     ataPB(a6),a4
-
-; Set bit 31 ("RAM based driver at run time") in the d5 passed to DRVR
-                move.l  #0,var_flags(a6)
-                tst.b   arg_romdrvr+3(a6)
-                bne.s   is_romdrvr
-                ori.b   #$80,var_flags(a6)      ; set the flag
-is_romdrvr:
-
-; Get the "IDENTIFY DEVICE" block with CHS information
-                move.l  #0,    $00(a4)      ;     ataPBLink
-                move.w  #0,    $04(a4)      ;     ataPBQType
-                move.b  #2,    $06(a4)      ; --> ataPBVers
-                move.b  #0,    $13(a4)      ; --> ataPBIOSpeed
-                move.w  arg_dev+2(a6),d1
-                ext.l   d1
-                move.l  d1,    $18(a4)      ; --> ataPBDeviceID
-                move.l  #0,    $08(a4)      ;  ?  ataPBReserved2
-                move.l  #20000,$1C(a4)      ; --> ataPBTimeOut
-                move.b  #$13,  $12(a4)      ; --> ataPBFunctionCode = kATAMgrDriveIdentify
-                move.w  #$2000,$14(a4)      ; --> ataPBFlags = mATAFlagIORead
-                move.w  #0,    $28(a4)      ;  ?  ataPBState
-                move.l  a3,    $38(a4)      ;     ataPBBuffer
-
-                sub.l   #2,sp
-                move.l  a4,-(sp)
-                dc.w    $AAF1               ; ATAManager
-                move.w  (sp)+,d0
-                ext.l   d0
-                bne     itr_return
-
-; Parse the "IDENTIFY DEVICE" block
-                move.w  2(a3),var_bstruct_0(a6) ; typically 1041
-                move.w  6(a3),var_bstruct_2(a6) ; typically 0010
-                move.w  $C(a3),var_bstruct_4(a6) ; typically 003f
-                move.w  var_bstruct_2(a6),d0 ; can't safely get rid of these for some reason!
-                mulu.w  var_bstruct_4(a6),d0
-                move.w  d0,var_bstruct_6(a6)
-
-; Send "Init drive parameters"
-                move.b  #$1,  $12(a4)       ; --> ataPBFunctionCode = IO (not in headers)
-                move.w  #0,   $14(a4)       ; --> ataPBFlags
-                move.w  #0,   $28(a4)       ;  ?  ataPBState
-                move.b  #$91, $48+$7(a4)    ;     ataPBTaskFile.ataTFCommand = kATAcmdInitDrive
-                move.l  arg_dev(a6),d0            ; (leaving bit $40 as zero for CHS)
-                lsr.l   #4,d0
-                and.l   #$10,d0                 ; master/slave bit
-                or.l    #$A0,d0                 ; sector size ? 512
-                move.w  var_bstruct_2(a6),d1
-                sub.w   #1,d1
-                or.w    d1,d0                   ; head number
-                move.b  d0,   $48+$6(a4)    ;     ataPBTaskFile.ataTFSDH
-                move.b  var_bstruct_4+1(a6),$48+$1(a4);     ataPBTaskFile.ataTFCount
-
-                sub.l   #2,sp
-                move.l  a4,-(sp)
-                dc.w    $AAF1               ; ATAManager
-                move.w  (sp)+,d0
-
-; Loop over all partitions, ask the driver to pick a bootable one
-                move.w  #$2000,ataPBFlags(a6)
-                move.l  #$200,ataPB34(a6)
-                move.b  #$20,ataPBTaskFile_ataTFCommand(a6)
-                move.l  #1,d5 ; Initially check only one partition, increase this number later
-                moveq   #0,d6 ; Partition index counter
-tellDriverAboutPartitionLoop:
-
-                move.l  d6,d0
-                addq.l  #1,d6
-                cmp.l   d0,d5
-                bcs.s   itr_fail
-                move.l  a3,ataPB38(a6)
-                move.l  #$200,ataPB3C(a6)
-                move.b  #1,ataPBTaskFile_ataTFCount(a6)
-                pea     var_bstruct_0(a6)
-                move.l  d6,-(sp)
-                pea     ataPB(a6)
-                bsr     paramblk_helper_function
-                subq.l  #2,sp
-                pea     ataPB(a6)
-                dc.w    $AAF1     ;;;;;;;;;;;;;;;;;;;;;;;;; kATAcmdRead again (get next PM entry)
-                move.w  (sp)+,d7
-                lea     $C(sp),sp
-                moveq   #0,d0
-                move.w  (a3),d0
-                cmpi.l  #'PM',d0
-                bne.s   tellDriverAboutPartitionLoop
-                move.l  4(a3),d5 ; update the *real* number of partitions, so we don't end early
-                move.l  var_flags(a6),-(sp) ; var_flags, obviously
-                move.w  var_arg2(a6),d0
-                ext.l   d0
-                move.l  d0,-(sp) ; arg_dev+2 extended to a long, pretty much always zero
-                move.l  a3,-(sp) ; pointer to this partition map entry
-                move.l  a2,-(sp) ; pointer to driver
-                bsr     *+2+'BT' ; BOOT function
-                move.l  d0,d4
-
-                lea     $10(sp),sp
-                move.w  d4,d7 ; -1 means try a different partition, 0 means succes, otherwise error
-                cmpi.w  #$FFFF,d7
-                beq.s   tellDriverAboutPartitionLoop
-
-                tst.w   d7
-                bne.s   itr_fail
-
-                move.l  d4,d0 ; the final pathway for success
-                bra.s   itr_return
-
-itr_fail:
-                move.l  #$FFFFDB93,d0   ; ATANoDriverErr
-
-itr_return:
-                movem.l var_regs(a6),d3-d7/a2-a4
-                unlk    a6
-                rts
-
-
-paramblk_helper_function:
-                link    a6,#0
-                movem.l d6-d7/a3-a4,-(sp)
-                move.l  $C(a6),d7
-                movea.l $10(a6),a3
-                movea.l $8(a6),a4
-                move.l  $18(a4),d0
-                lsr.l   #8,d0
-                moveq   #1,d6
-                and.l   d0,d6
-                clr.w   $28(a4)
-                moveq   #0,d0
-                move.w  6(a3),d0
-                move.l  d7,d1
-                divu.l  d0,d1
-                move.w  d1,$4C(a4)
-                moveq   #0,d0
-                move.w  4(a3),d0
-                move.l  d7,d1
-                divu.l  d0,d1
-                moveq   #0,d0
-                move.w  2(a3),d0
-                tst.l   d0
-                tdivs.l d0,d2:d1
-                moveq   #$F,d0
-                and.l   d2,d0
-                move.b  d0,$4E(a4)
-                move.l  d6,d0
-                lsl.l   #4,d0
-                or.b    d0,$4E(a4)
-                ori.b   #$A0,$4E(a4)
-                moveq   #0,d0
-                move.w  4(a3),d0
-                move.l  d7,d1
-                tdivu.l d0,d2:d1
-                addq.b  #1,d2
-                move.b  d2,$4A(a4)
-                movem.l -$10(a6),d6-d7/a3-a4
-                unlk    a6
-                rts
+    END
 
 
         string c
diff --git a/ATALoad.dmp b/ATALoad.dmp
index c79df73..ebe36e0 100644
--- a/ATALoad.dmp
+++ b/ATALoad.dmp
@@ -11,7 +11,7 @@ Pad
 Module:              Flags=$10=(Main Local Code)  Module="#0001"(1) Segment="Main"(2)
 
 Content:             Flags $08
-Contents offset $0000 size $0236
+Contents offset $0000 size $008E
 00000000: 41EF 0010      'A...'            LEA        $0010(A7),A0
 00000004: 2F20           '/ '              MOVE.L     -(A0),-(A7)
 00000006: 2F20           '/ '              MOVE.L     -(A0),-(A7)
@@ -26,161 +26,35 @@ Contents offset $0000 size $0236
 00000022: 4E73           'Ns'              RTE        
 00000024: 7274           'rt'              MOVEQ      #$74,D1             ; 't'
 00000026: 6000 4944      '`.ID'            BRA        *+$4946             ; 0000496C
-0000002A: 4E56 FB26      'NV.&'            LINK       A6,#$FB26
-0000002E: 48E7 1F38      'H..8'            MOVEM.L    D3-D7/A2-A4,-(A7)
-00000032: 41EE FB26      'A..&'            LEA        -$04DA(A6),A0
-00000036: 4258           'BX'              CLR.W      (A0)+
-00000038: BDC8           '..'              CMPA.L     A0,A6
-0000003A: 66FA           'f.'              BNE.S      *-$0004             ; 00000036
-0000003C: 0CAE 0000 0701 '......'          CMPI.L     #$00000701,$000C(A6)
-             000C           
-00000044: 6600 0164      'f..d'            BNE        *+$0166             ; 000001AA
-00000048: 31FC FFFF 0B9E '1.....'          MOVE.W     #$FFFF,$0B9E
-0000004E: 2F3C 4452 5652 '/<DRVR'          MOVE.L     #$44525652,-(A7)    ; 'DRVR'
-00000054: 3F3C 0035      '?<.5'            MOVE.W     #$0035,-(A7)
-00000058: A9A0           '..'              _GetResource                      ; A9A0
-0000005A: 245F           '$_'              MOVEA.L    (A7)+,A2
-0000005C: 4A8A           'J.'              TST.L      A2
-0000005E: 6700 014A      'g..J'            BEQ        *+$014C             ; 000001AA
-00000062: 2452           '$R'              MOVEA.L    (A2),A2
-00000064: 47EE FBF8      'G...'            LEA        -$0408(A6),A3
-00000068: 49EE FB26      'I..&'            LEA        -$04DA(A6),A4
-0000006C: 42AE FFF8      'B...'            CLR.L      -$0008(A6)
-00000070: 4A2E 0013      'J...'            TST.B      $0013(A6)
-00000074: 6606           'f.'              BNE.S      *+$0008             ; 0000007C
-00000076: 002E 0080 FFF8 '......'          ORI.B      #$80,-$0008(A6)
-0000007C: 4294           'B.'              CLR.L      (A4)
-0000007E: 426C 0004      'Bl..'            CLR.W      $0004(A4)
-00000082: 197C 0002 0006 '.|....'          MOVE.B     #$02,$0006(A4)
-00000088: 422C 0013      'B,..'            CLR.B      $0013(A4)
-0000008C: 322E 000A      '2...'            MOVE.W     $000A(A6),D1
-00000090: 48C1           'H.'              EXT.L      D1
-00000092: 2941 0018      ')A..'            MOVE.L     D1,$0018(A4)
-00000096: 42AC 0008      'B...'            CLR.L      $0008(A4)
-0000009A: 297C 0000 4E20 ')|..N '          MOVE.L     #$00004E20,$001C(A4)
-             001C           
-000000A2: 197C 0013 0012 '.|....'          MOVE.B     #$13,$0012(A4)
-000000A8: 397C 2000 0014 '9| ...'          MOVE.W     #$2000,$0014(A4)
-000000AE: 426C 0028      'Bl.('            CLR.W      $0028(A4)
-000000B2: 294B 0038      ')K.8'            MOVE.L     A3,$0038(A4)
-000000B6: 558F           'U.'              SUBQ.L     #$2,A7
-000000B8: 2F0C           '/.'              MOVE.L     A4,-(A7)
-000000BA: AAF1           '..'              DC.W       $AAF1               ; TB 02F1
-000000BC: 301F           '0.'              MOVE.W     (A7)+,D0
-000000BE: 48C0           'H.'              EXT.L      D0
-000000C0: 6600 00EE      'f...'            BNE        *+$00F0             ; 000001B0
-000000C4: 3D6B 0002 FBDE '=k....'          MOVE.W     $0002(A3),-$0422(A6)
-000000CA: 3D6B 0006 FBE0 '=k....'          MOVE.W     $0006(A3),-$0420(A6)
-000000D0: 3D6B 000C FBE2 '=k....'          MOVE.W     $000C(A3),-$041E(A6)
-000000D6: 302E FBE0      '0...'            MOVE.W     -$0420(A6),D0
-000000DA: C0EE FBE2      '....'            MULU.W     -$041E(A6),D0
-000000DE: 3D40 FBE4      '=@..'            MOVE.W     D0,-$041C(A6)
-000000E2: 197C 0001 0012 '.|....'          MOVE.B     #$01,$0012(A4)
-000000E8: 426C 0014      'Bl..'            CLR.W      $0014(A4)
-000000EC: 426C 0028      'Bl.('            CLR.W      $0028(A4)
-000000F0: 197C 0091 004F '.|...O'          MOVE.B     #$91,$004F(A4)
-000000F6: 202E 0008      ' ...'            MOVE.L     $0008(A6),D0
-000000FA: E888           '..'              LSR.L      #$4,D0
-000000FC: 0280 0000 0010 '......'          ANDI.L     #$00000010,D0
-00000102: 0080 0000 00A0 '......'          ORI.L      #$000000A0,D0
-00000108: 322E FBE0      '2...'            MOVE.W     -$0420(A6),D1
-0000010C: 5341           'SA'              SUBQ.W     #$1,D1
-0000010E: 8041           '.A'              OR.W       D1,D0
-00000110: 1940 004E      '.@.N'            MOVE.B     D0,$004E(A4)
-00000114: 196E FBE3 0049 '.n...I'          MOVE.B     -$041D(A6),$0049(A4)
-0000011A: 558F           'U.'              SUBQ.L     #$2,A7
-0000011C: 2F0C           '/.'              MOVE.L     A4,-(A7)
-0000011E: AAF1           '..'              DC.W       $AAF1               ; TB 02F1
-00000120: 301F           '0.'              MOVE.W     (A7)+,D0
-00000122: 3D7C 2000 FB3A '=| ..:'          MOVE.W     #$2000,-$04C6(A6)
-00000128: 2D7C 0000 0200 '-|....'          MOVE.L     #$00000200,-$04A6(A6)
-             FB5A           
-00000130: 1D7C 0020 FB75 '.|. .u'          MOVE.B     #$20,-$048B(A6)     ; ' '
-00000136: 7A01           'z.'              MOVEQ      #$01,D5
-00000138: 7C00           '|.'              MOVEQ      #$00,D6
-0000013A: 2006           ' .'              MOVE.L     D6,D0
-0000013C: 5286           'R.'              ADDQ.L     #$1,D6
-0000013E: BA80           '..'              CMP.L      D0,D5
-00000140: 6568           'eh'              BCS.S      *+$006A             ; 000001AA
-00000142: 2D4B FB5E      '-K.^'            MOVE.L     A3,-$04A2(A6)
-00000146: 2D7C 0000 0200 '-|....'          MOVE.L     #$00000200,-$049E(A6)
-             FB62           
-0000014E: 1D7C 0001 FB6F '.|...o'          MOVE.B     #$01,-$0491(A6)
-00000154: 486E FBDE      'Hn..'            PEA        -$0422(A6)
-00000158: 2F06           '/.'              MOVE.L     D6,-(A7)
-0000015A: 486E FB26      'Hn.&'            PEA        -$04DA(A6)
-0000015E: 6100 005A      'a..Z'            BSR        *+$005C             ; 000001BA
-00000162: 558F           'U.'              SUBQ.L     #$2,A7
-00000164: 486E FB26      'Hn.&'            PEA        -$04DA(A6)
-00000168: AAF1           '..'              DC.W       $AAF1               ; TB 02F1
-0000016A: 3E1F           '>.'              MOVE.W     (A7)+,D7
-0000016C: 4FEF 000C      'O...'            LEA        $000C(A7),A7
-00000170: 7000           'p.'              MOVEQ      #$00,D0
-00000172: 3013           '0.'              MOVE.W     (A3),D0
-00000174: 0C80 0000 504D '....PM'          CMPI.L     #$0000504D,D0
-0000017A: 66BE           'f.'              BNE.S      *-$0040             ; 0000013A
-0000017C: 2A2B 0004      '*+..'            MOVE.L     $0004(A3),D5
-00000180: 2F2E FFF8      '/...'            MOVE.L     -$0008(A6),-(A7)
-00000184: 302E FBF2      '0...'            MOVE.W     -$040E(A6),D0
-00000188: 48C0           'H.'              EXT.L      D0
-0000018A: 2F00           '/.'              MOVE.L     D0,-(A7)
-0000018C: 2F0B           '/.'              MOVE.L     A3,-(A7)
-0000018E: 2F0A           '/.'              MOVE.L     A2,-(A7)
-00000190: 6100 4254      'a.BT'            BSR        *+$4256             ; 000043E6
-00000194: 2800           '(.'              MOVE.L     D0,D4
-00000196: 4FEF 0010      'O...'            LEA        $0010(A7),A7
-0000019A: 3E04           '>.'              MOVE.W     D4,D7
-0000019C: 0C47 FFFF      '.G..'            CMPI.W     #$FFFF,D7
-000001A0: 6798           'g.'              BEQ.S      *-$0066             ; 0000013A
-000001A2: 4A47           'JG'              TST.W      D7
-000001A4: 6604           'f.'              BNE.S      *+$0006             ; 000001AA
-000001A6: 2004           ' .'              MOVE.L     D4,D0
-000001A8: 6006           '`.'              BRA.S      *+$0008             ; 000001B0
-000001AA: 203C FFFF DB93 ' <....'          MOVE.L     #$FFFFDB93,D0
-000001B0: 4CEE 1CF8 FB06 'L.....'          MOVEM.L    -$04FA(A6),D3-D7/A2-A4
-000001B6: 4E5E           'N^'              UNLK       A6
-000001B8: 4E75           'Nu'              RTS        
-000001BA: 4E56 0000      'NV..'            LINK       A6,#$0000
-000001BE: 48E7 0318      'H...'            MOVEM.L    D6/D7/A3/A4,-(A7)
-000001C2: 2E2E 000C      '....'            MOVE.L     $000C(A6),D7
-000001C6: 266E 0010      '&n..'            MOVEA.L    $0010(A6),A3
-000001CA: 286E 0008      '(n..'            MOVEA.L    $0008(A6),A4
-000001CE: 202C 0018      ' ,..'            MOVE.L     $0018(A4),D0
-000001D2: E088           '..'              LSR.L      #$8,D0
-000001D4: 7C01           '|.'              MOVEQ      #$01,D6
-000001D6: CC80           '..'              AND.L      D0,D6
-000001D8: 426C 0028      'Bl.('            CLR.W      $0028(A4)
-000001DC: 7000           'p.'              MOVEQ      #$00,D0
-000001DE: 302B 0006      '0+..'            MOVE.W     $0006(A3),D0
-000001E2: 2207           '".'              MOVE.L     D7,D1
-000001E4: 4C40 1001      'L@..'            DIVU.L     D0,D1
-000001E8: 3941 004C      '9A.L'            MOVE.W     D1,$004C(A4)
-000001EC: 7000           'p.'              MOVEQ      #$00,D0
-000001EE: 302B 0004      '0+..'            MOVE.W     $0004(A3),D0
-000001F2: 2207           '".'              MOVE.L     D7,D1
-000001F4: 4C40 1001      'L@..'            DIVU.L     D0,D1
-000001F8: 7000           'p.'              MOVEQ      #$00,D0
-000001FA: 302B 0002      '0+..'            MOVE.W     $0002(A3),D0
-000001FE: 4A80           'J.'              TST.L      D0
-00000200: 4C40 1802      'L@..'            TDIVS.L    D0,D2:D1
-00000204: 700F           'p.'              MOVEQ      #$0F,D0
-00000206: C082           '..'              AND.L      D2,D0
-00000208: 1940 004E      '.@.N'            MOVE.B     D0,$004E(A4)
-0000020C: 2006           ' .'              MOVE.L     D6,D0
-0000020E: E988           '..'              LSL.L      #$4,D0
-00000210: 812C 004E      '.,.N'            OR.B       D0,$004E(A4)
-00000214: 002C 00A0 004E '.,...N'          ORI.B      #$A0,$004E(A4)
-0000021A: 7000           'p.'              MOVEQ      #$00,D0
-0000021C: 302B 0004      '0+..'            MOVE.W     $0004(A3),D0
-00000220: 2207           '".'              MOVE.L     D7,D1
-00000222: 4C40 1002      'L@..'            TDIVU.L    D0,D2:D1
-00000226: 5202           'R.'              ADDQ.B     #$1,D2
-00000228: 1942 004A      '.B.J'            MOVE.B     D2,$004A(A4)
-0000022C: 4CEE 18C0 FFF0 'L.....'          MOVEM.L    -$0010(A6),D6/D7/A3/A4
-00000232: 4E5E           'N^'              UNLK       A6
-00000234: 4E75           'Nu'              RTS        
+0000002A: 4E56 FFFC      'NV..'            LINK       A6,#$FFFC
+0000002E: 48EE 0020 FFFC 'H.. ..'          MOVEM.L    D5,-$0004(A6)
+00000034: 0C6E 0701 000E '.n....'          CMPI.W     #$0701,$000E(A6)
+0000003A: 6642           'fB'              BNE.S      *+$0044             ; 0000007E
+0000003C: 203C 5369 7A65 ' <Size'          MOVE.L     #$53697A65,D0       ; 'Size'
+00000042: A51E           '..'              _NewPtr    ,Sys                ; A51E
+00000044: 4A88           'J.'              TST.L      A0
+00000046: 6736           'g6'              BEQ.S      *+$0038             ; 0000007E
+00000048: 2248           '"H'              MOVEA.L    A0,A1
+0000004A: 41FA 4174      'A.At'            LEA        *+$4176,A0          ; 000041C0
+0000004E: 203C 5369 7A65 ' <Size'          MOVE.L     #$53697A65,D0       ; 'Size'
+00000054: A02E           '..'              _BlockMove                      ; A02E
+00000056: 2A2E 0008      '*...'            MOVE.L     $0008(A6),D5
+0000005A: 0285 0000 FF00 '......'          ANDI.L     #$0000FF00,D5
+00000060: 202E 0008      ' ...'            MOVE.L     $0008(A6),D0
+00000064: 4840           'H@'              SWAP       D0
+00000066: 0280 00FF 0000 '......'          ANDI.L     #$00FF0000,D0
+0000006C: 8A80           '..'              OR.L       D0,D5
+0000006E: 4A2E 0013      'J...'            TST.B      $0013(A6)
+00000072: 6604           'f.'              BNE.S      *+$0006             ; 00000078
+00000074: 08C5 001F      '....'            BSET       #$1F,D5
+00000078: 4EA8 0008      'N...'            JSR        $0008(A0)
+0000007C: 6006           '`.'              BRA.S      *+$0008             ; 00000084
+0000007E: 203C FFFF DB93 ' <....'          MOVE.L     #$FFFFDB93,D0
+00000084: 4CEE 0020 FFFC 'L.. ..'          MOVEM.L    -$0004(A6),D5
+0000008A: 4E5E           'N^'              UNLK       A6
+0000008C: 4E75           'Nu'              RTS        
 
-Size:                Flags $00 ModuleSize 566
+Size:                Flags $00 ModuleSize 142
 
 Last        
 Record Summary 
diff --git a/DRVR_53_ATADisk b/AppleATADisk
similarity index 100%
rename from DRVR_53_ATADisk
rename to AppleATADisk
diff --git a/ataboot.py b/ataboot.py
index 28c2b12..d810e80 100755
--- a/ataboot.py
+++ b/ataboot.py
@@ -11,28 +11,13 @@ import binascii
 
 
 src, cleanup = patch_common.get_src(desc='''
-Enable booting from ATA disks without an Apple_Driver_ATA partition. This is
-done by patching the ROM-based .ATALoad DRVR to fall back on the ROM-based
-.ATADisk DRVR when initially scanning a disk. The .ATADisk is added to the ROM
-if missing. The disk still needs an Apple Partition Map.
+Support ATA startup disks without an Apple_Driver_ATA partition. This allows Mac
+OS to be installed on a disk without repartitioning it. Accomplished by
+shoehorning the Drive Setup 2.1 ATA driver into the ROM ATALoad driver, to
+replace missing driver partitions.
 ''')
 
 
-# long BOOT(void *DRVR, void *PartMapEntry, long flags)
-# C calling convention: args pushed in reverse order and not popped by function, return value in d0
-def find_BOOT(code):
-    for i in range(0, len(code), 2):
-        if code[i:i+4] == b'BOOT': # MOVE.L 'BOOT',D0  --or-- MOVE.L 'BOOT',-(SP)
-            for j in reversed(range(0, i, 2)):
-                # Count backwards and look for the target of *any* JSR, which is the start of the func
-                for k in range(0, len(code), 2):
-                    if code[k:k+2] == b'\x4E\xBA': # JSR opcode
-                        if k+2 + struct.unpack('>h', code[k+2:k+4])[0] == j:
-                            return j
-
-    raise ValueError('Function BOOT not found')
-
-
 def find_InitDevice(code):
     for i in range(0, len(code), 2):
         # checking Driver Descriptor Map magic number (there are two but this one always first)
@@ -46,7 +31,7 @@ def find_InitDevice(code):
 
 def patch_ataload(code):
     code = bytearray(code)
-    new = len(code) # boundary between old and new code
+    cut1 = len(code) # boundary between original and glue
 
     # Parse the DumpObj'd file
     with open(path.join(path.dirname(__file__), 'ATALoad.dmp')) as f:
@@ -55,46 +40,50 @@ def patch_ataload(code):
             if m:
                 code.extend(binascii.unhexlify(m.group(1).replace(' ', '')))
 
-    InitDevice = find_InitDevice(code[:new])
-    BOOT = find_BOOT(code[:new])
+    cut2 = len(code) # boundary between glue and driver
 
-    print('ATALoad patch: InitDevice=0x%X, NewInitDevice=0x%X, BOOT=0x%X' % (InitDevice, new, BOOT))
+    with open(path.join(path.dirname(__file__), 'AppleATADisk'), 'rb') as f:
+        code.extend(f.read())
+
+    InitDevice = find_InitDevice(code[:cut1])
+
+    print('ATALoad patch: InitDevice=0x%X, glue=0x%X, driver=0x%X' % (InitDevice, cut1, cut2))
 
     # "Link" the new code into the old
-    for i in range(new, len(code), 2):
+    for i in range(cut1, len(code), 2):
         if code[i:i+4] == b'Nsrt':
             code[i:i+4] = code[InitDevice:InitDevice+4] # copy the first LINK from the original function
             code[InitDevice:InitDevice+2] = b'\x60\x00' # BRA.W opcode, to...
-            code[InitDevice+2:InitDevice+4] = struct.pack('>h', new - (InitDevice+2)) # ...the start of the new code
+            code[InitDevice+2:InitDevice+4] = struct.pack('>h', cut1 - (InitDevice+2)) # ...the start of the new code
+
+        if code[i:i+2] == b'At':
+            code[i:i+2] = struct.pack('>h', cut2 - i)
+
+        if code[i:i+4] == b'Size':
+            code[i:i+4] = struct.pack('>l', cut2 - cut1)
 
         if code[i:i+2] == b'ID': # reference to original InitDevice, skipping the mangled 4-byte LINK
             code[i:i+2] = struct.pack('>h', (InitDevice+4) - i)
 
-        if code[i:i+2] == b'BT': # reference to BOOT function
-            code[i:i+2] = struct.pack('>h', BOOT - i)
-
     return bytes(code)
 
 
+found_drvr = False
+
 for (parent, folders, files) in os.walk(src):
     folders.sort(); files.sort() # make it kinda deterministic
     for filename in files:
         full = path.join(src, parent, filename)
 
-        if filename == 'Romfile':
-            ataload = path.join(src, parent, 'Rsrc', 'DRVR_-20175_ATALoad')
-            atadisk = path.join(src, parent, 'Rsrc', 'DRVR_53_ATADisk')
+        if filename == 'DRVR_-20175_ATALoad':
+            code = open(full, 'rb').read()
+            code = patch_ataload(code)
+            open(full, 'wb').write(code)
+            found_drvr = True
 
-            if path.exists(ataload):
-                code = open(ataload, 'rb').read()
-                code = patch_ataload(code)
-                open(ataload, 'wb').write(code)
 
-                if not path.exists(atadisk):
-                    with open(full, 'a') as f: # append to Romfile
-                        f.write('\ntype=DRVR   id=53       name=.ATADisk           src=Rsrc/DRVR_53_ATADisk # inserted by ataboot.py\n')
-                print('ATALoad patch: using .ATADisk DRVR from Drive Setup 2.1')
-                shutil.copy(path.join(path.dirname(__file__), 'DRVR_53_ATADisk'), atadisk)
+if not found_drvr:
+    raise ValueError('ATALoad DRVR not found')
 
 
 cleanup()