FakeFinder

A tiny file-launching hack for those emergencies...

By Lee David Rimar

What with it being April and the call of April Fool’s Day echoing in the breezes, it seems an appropriate time to put before the public this little horror that arrived at our desks a while back. Please bear in mind that when we say, “Kids, don’t try this at home,” this is one case where we mean it. It really does work, but the publisher, editors and staff of MacTech Magazine categorically refuse to stand behind or endorse it in any way, and will not be held responsible for what happens to you or anyone else as a result of your assembling this code or downloading the alternate Finder app. In fact, we can’t even be held responsible for what may happen to you if you read the article! Why not just turn the page now? Hey, I said turn the page! Okay, you asked for it

What It Is and
Why You Might Want It

With current releases of the Mac OS, it’s sometimes hard to build a useful emergency boot diskette. If your hard-drive won’t boot, you can usually use the Disk Tools floppy to bring up your system. But if you want other diagnostic and/or system recovery programs on your “emergency” diskette, there usually isn’t enough space. Enter FakeFinder.

FakeFinder is a tiny program (under 800 bytes) that simply launches other programs. On emergency boot diskettes, FakeFinder replaces the real Finder, and frees a lot of space.

How To Use It

To create an emergency boot disk with FakeFinder:

• Format a diskette and label it Emergency.

• Copy the following file(s) from your Disk Tools diskette to the root directory of Emergency:

1) the System file

2) optional: the Apple CD-ROM Extension

• If your Mac requires any system enablers, copy these also to the root directory of Emergency.

• Copy the “Finder” application from the FakeFinder package to the root directory of Emergency.

You now have a bootable diskette with considerable free space on it. Go ahead and add any other programs you want in the root directory of this disk, anything that will fit. My personal preference is to keep most of what’s on the Disk Tools floppy, and add my tape backup/restore software.

When you reboot with this diskette, FakeFinder loads and creates a File menu with only two items on it: Open and Quit.

To launch any program(s), select Open. This will let you select any applications, aliases to applications, and even a “real” Finder on any mounted drive - including CDs, if you copied the Apple CD-ROM Extension to the diskette.

To shut down your Mac, select Quit, and also quit any other applications you may have launched. Your Mac will then shut down normally.

Limitations
(or, This Ain’t No Swiss Army Knife)

To be so small, FakeFinder leaves a lot of stuff out. The most important limitations:

• No desk accesories/Apple Menu items.

• Without a real Finder present, you can’t use File Sharing.

• Programs needing to find a “Blessed Folder,” containing a real Finder and System, may not work.

The point of FakeFinder was to make it as small as possible, so I don’t plan to solve any of these problems.

By The Way: How Did It Get So Small?

Normally, to create an application this small, you would start in assembly language. But I don’t grok 68K assembler well enough to write anything from the ground up. So I wrote, compiled, linked, and tested FakeFinder using FORTRAN, a language I do know. Then I disassembled the compiler’s output, modified it to reduce the code size, and re-assembled it.

Disclaimers
(or, Anything Free Comes With No Guarantee)

Though FakeFinder works properly on every system I have tested so far, it may not work on tomorrow’s systems. This is because it uses the _Launch trap to sublaunch applications, and Apple says this functionality may go away in future OS releases. If and when that time comes, it will be necessary to rewrite any applications using the sublaunch facility.

References

Macintosh Tech Notes #126, #180, #205 (old numbering system).

MACHINE MC68000

; system routines used in this module

_AppendMenu     OPWORD  $A933
_DrawMenuBar    OPWORD  $A937
_ExitToShell    OPWORD  $A9F4
_FindWindow     OPWORD  $A92C
_HFSDispatch    OPWORD  $A260
_HiliteMenu     OPWORD  $A938
_InitCursor     OPWORD  $A850
_InitDialogs    OPWORD  $A97B
_InitFonts      OPWORD  $A8FE
_InitGraf       OPWORD  $A86E
_InitMenus      OPWORD  $A930
_InitWindows    OPWORD  $A912
_InsertMenu     OPWORD  $A935
_Launch         OPWORD  $A9F2
_MenuSelect     OPWORD  $A93D
_NewMenu        OPWORD  $A931
_StdFile        OPWORD  $A9EA
_SetVol         OPWORD  $A015
_WaitNextEvent  OPWORD  $A860

START:  MAIN

; make a stack, initialize managers, and set up menus

        link            a6,#-664

        lea             (266,a7),a2 ; qd.grafport
        move.l          a2,(a7)
        _InitGraf
        _InitFonts
        _InitWindows
        _InitMenus
        _InitDialogs
        _InitCursor

        lea             AppleMenu,a2
        move.l          a2,(a7)
        move.w          #$80,(4,a7)
        _NewMenu
        move.l          (a7),a3
        move.w          #0,(a7)
        move.l          a3,(2,a7)
        _InsertMenu
        lea             FileMenu,a2
        move.l          a2,(a7)
        move.w          #$81,(4,a7)
        _NewMenu
        move.l          (a7),a3
        move.w          #0,(a7)
        move.l          a3,(2,a7)
        _InsertMenu
        lea             MenuItems,a2
        move.l          a2,(a7)
        move.l          a3,(4,a7)
        _AppendMenu
        _DrawMenuBar

        sub.l           #36,a7

Loop:

; If (.NOT. WaitNextEvent(
;       VAL2(-1),event,VAL(15),VAL(0))) Loop

        move.l          #0,(a7)
        move.l          #15,(4,a7)
        lea             (288,a7),a2
        move.l          a2,(8,a7)
        move.w          #-1,(12,a7)
        _WaitNextEvent
        move.b          (a7),d3
        sub.l           #$000e,a7
        tst.b           d3
        beq.s           Loop

; If (event.what != mouseDown) Loop

        move.w          (288,a7),d3
        cmp.w           #1,d3
        bne.s           Loop

; If (FindWindow(
;       VAL(event.where),dummy) != inMenuBar) Loop

        lea             (272,a7),a2
        move.l          a2,(a7)
        move.l          (298,a7),(4,a7)
        _FindWindow
        move.w          (a7),d3
        sub.l           #8,a7
        cmp.w           #1,d3
        bne.s           Loop

; pick = MenuSelect(VAL(event.where))
; Call HiliteMenu(VAL2(0))

        move.l          (298,a7),(a7)
        _MenuSelect
        move.l          (a7),d3
        move.w          #0,(a7)
        _HiliteMenu
        sub.l           #6,a7

; If (pick == z'00810001') GetFile
; If (pick != z'00810002') Loop
; Call ExitToShell

        cmp.l           #$810001,d3
        beq.s           GetFile
        cmp.l           #$810002,d3
        bne.s           Loop

        _ExitToShell

GetFile:

; Call SFGetFile(
;       VAL(coords),0,VAL(0),VAL2(3),types,VAL(0),reply)

        lea             (304,a7),a2
        move.l          a2,(a7)
        move.l          #0,(4,a7)
        lea             types,a2
        move.l          a2,(8,a7)
        move.w          #3,(12,a7)
        move.l          #0,(14,a7)
        move.l          #0,(18,a7)
        move.l          #$00400040,(22,a7)
        move.w          #$2,-(a7)
        _StdFile
        sub.l           #$001a,a7

; If (.NOT. reply.good) Loop

        move.b          (304,a7),d3
        tst.b           d3
        beq.s           final

; myPB.p_ioName = LOC(reply.fName)
; myPB.ioVRefNum = reply.vRefNum
; myPB.ioFDirIndex = 0
; myPB.ioDirID = 0
; If (PBGetCatInfoSync(myPB) != 0) Loop

        lea             (314,a7),a2
        move.l          a2,(478,a7)
        move.w          (310,a7),(482,a7)
        move.l          #0,(488,a7)
        move.l          #0,(508,a7)
        lea             (460,a7),a2
        move.l          a2,(a7)
        movea.l         (a7)+,a0
        move.w          #9,d0
        _HFSDispatch
        sub.l           #4,a7
        tst.w           d0
        bne.s           final

; params.ioCompletion = 0
; params.ioResult = 0
; params.p_ioName = 0
; params.ioVRefNum = reply.vRefNum
; If(PBSetVolSync(params).LT.0) Loop

        move.l          #0,(392,a7)
        move.w          #0,(396,a7)
        move.l          #0,(398,a7)
        move.w          (310,a7),(402,a7)
        lea             (380,a7),a2
        move.l          a2,(a7)
        movea.l         (a7)+,a0
        _SetVol
        sub.l           #4,a7

; ap.pfName = LOC(reply.fName)
; ap.param = 0
; ap.LC = z'4C43'
; ap.extBlockLen = 6
; ap.fFlags = myPB.ioFlFndrInfo.fdFlags
; ap.launchFlags = z'C0000000'

        lea             (314,a7),a2
        move.l          a2,(568,a7)
        move.w          #0,(572,a7)
        move.w          #$4C43,(574,a7)
        move.l          #6,(576,a7)
        move.w          (500,a7),(580,a7)
        move.l          #$c0000000,(582,a7)

; ignore = launch(ap)

        lea             (568,a7),a2
        move.l          a2,(a7)
        movea.l         (a7)+,a0
        _Launch
        sub.l           #4,a7

final:  bra             Loop

; some constants embedded in code section

types: ; file types for getfile, what you can launch with FakeFinder

        dc.l            $4150504c ; APPL
        dc.l            $464e4452 ; FNDR
        dc.l            $61647270 ; adrp (application aliases)

AppleMenu: ; Apple Menu character, for appearances only!

        dc.b    1
        dc.b    20

FileMenu: ; Pascal String “File”

        dc.b    4
        dc.b    70
        dc.b    105
        dc.b    108
        dc.b    101
        dc.b    0 ; pad so next lands on even address

MenuItems: ; Pascal string “Open;Quit”

        dc.b    9
        dc.b    79
        dc.b    112
        dc.b    101
        dc.b    110
        dc.b    59
        dc.b    81
        dc.b    117
        dc.b    105
        dc.b    116

        ENDMAIN
        END