-----------Alice in Logoland-----------
A 4am crack                  2014-06-16
---------------------------------------

"Alice in Logoland" is a disk of sample
Logo programs that was bundled with
Krell's Logo, distributed by Krell
Software.

The original disk boots to DOS and
displays a disk catalog, then exits.
The files are meant to be loaded
by booting the Krell's Logo program
disk, then loading the files through
the Logo interactive shell.

COPYA barfs immediately on the original
disk. Turning to my trusty Copy ][+
sector editor, I press "P" to enter the
Sector Editor Patcher, then select "DOS
3.3 PATCHED" (which ignores address
field checksums and epilogue bytes).
Behold! All tracks and sectors are
readable.

Given the (relatively) weak structural
protection, I used to turn to the DOS
3.3 master disk, patch the RWTS to
ignore checksums and epilogue bytes
(changing $B942 from "SEC" to "CLC"),
and run COPYA. Then, one fine day, and
completely by accident, I came across
an original disk with a bad sector. I
suppose this shouldn't surprise me.
These floppies are decades old by now;
it's amazing any of them work at all.

The point is, I shouldn't be using
tools that ignore potentially serious
read errors. There are other tools,
like Super Demuffin, that can convert a
disk like this (with non-standard
epilogue bytes) into a standard format.
It requires figuring out what the
actual epilogue bytes are, but it has
the advantage of surfacing a read error
if the original disk actually has a
read error.

So... no more COPYA+B942:18 patch. From
now on, it's Super Demuffin or Advanced
Demuffin to convert disks to a standard
format. Given that this disk is self-
booting, I should be able to use my
AUTOTRACE program to extract the RWTS
from the original disk, then load that
into Advanced Demuffin to convert it to
a standard format.

[S6,D1=original disk]
[S5,D1=my work disk]

]PR#5
...
CAPTURING BOOT0
...reboots slot 6...
...reboots slot 5...
SAVING BOOT0
CAPTURING BOOT1
...reboots slot 6...
...reboots slot 5...
SAVING BOOT1
SAVING RWTS

For those of you just tuning in, my
work disk uses a custom program that I
affectionately call "AUTOTRACE" to
automate the process of boot tracing as
far as possible. For some disks, this
just captures track 0, sector 0 (saved
in a file called "BOOT0") and stops.
For other disks that load in the same
way that an unprotected DOS 3.3 disk
loads, it captures the next stage of
the boot process as well (in a file
called "BOOT1"). BOOT1 contains sectors
0-9 on track 0, which are loaded into
memory at $B600..$BFFF. This generally
contains the RWTS routines which the
program uses to read the rest of the
disk.

If the RWTS is fairly normal as well
(and my AUTOTRACE program just spot-
checks a few memory locations to guess
at its "normalcy"), there's a good
chance I'll be able to use a tool
called Advanced Demuffin (written in
1983 by The Stack) to convert the disk
from whatever weird format it uses to
store its sector data into a standard
disk readable by unprotected DOS 3.3
disks or any other third-party tools.
In this case, AUTOTRACE extracts the
RWTS routines (generally loaded from
track 0, sectors 2-9 into $B800..$BFFF)
and saves *that* into a third file
called "RWTS".

If anything looks fishy or non-
standard, AUTOTRACE just stops, and I
have to check the files it saved so far
to determine why. But in this case, it
ran all the way through, automatically
capturing BOOT0, BOOT1, and RWTS files.
Now I can use Advanced Demuffin to
convert the disk to a standard format.
(It uses the disk's own RWTS to read
the original, then a standard DOS 3.3-
compatible RWTS to write out the data,
sector by sector.)

[S6,D1=my work disk]

]PR#6
]BRUN ADVANCED DEMUFFIN 1.1

--> LOAD NEW RWTS MODULE
    At $B8, load "RWTS"
    from D1

[S6,D1=original disk]
[S6,D2=blank disk]

--> FORMAT TARGET DISK

...grind grind grind...

--> CONVERT DISK

This disk is 16 sectors, and the
default options (copy the entire disk,
all tracks, all sectors) don't need to
be changed unless something goes
horribly wrong.

                 --v--

ADVANCED DEMUFFIN 1.1  - COPYRIGHT 1983
WRITTEN BY THE STACK -CORRUPT COMPUTING
=======PRESS ANY KEY TO CONTINUE=======
TRK:...................................
+.5:
    0123456789ABCDEF0123456789ABCDEF012
SC0:...................................
SC1:...................................
SC2:...................................
SC3:...................................
SC4:...................................
SC5:...................................
SC6:...................................
SC7:...................................
SC8:...................................
SC9:...................................
SCA:...................................
SCB:...................................
SCC:...................................
SCD:...................................
SCE:...................................
SCF:...................................
=======================================
16 SC $00,$00 TO $22,$0F BY $01 TO DRV2

                 --^--

Rebooting my work disk, I can see the
disk catalog on the demuffin'd copy.

[S6,D1=demuffin'd copy]
[S5,D1=my work disk]

]PR#5
...
]CATALOG,S6,D1

C1983 DSR^C#254
117 FREE

*B 016 AIL1.LOGO
*B 017 AIL10.LOGO
*B 012 AIL11.LOGO
*B 014 AIL12.LOGO
*B 012 AIL13.LOGO
*B 018 AIL14.LOGO
*B 015 AIL15.LOGO
*B 012 AIL16.LOGO
*B 019 AIL17.LOGO
*B 017 AIL18.LOGO
*B 015 AIL19.LOGO
*B 007 AIL1A.LOGO
*B 014 AIL2.LOGO
*B 013 AIL20.LOGO
*B 018 AIL21.LOGO
*B 009 AIL2B.LOGO
*B 014 AIL3.LOGO
*B 009 AIL3A.LOGO
*B 017 AIL4.LOGO
*B 013 AIL5.LOGO
*B 014 AIL6.LOGO
*B 016 AIL7.LOGO
*B 018 AIL8.LOGO
*B 012 AIL9.LOGO
*B 003 ALICE.AUX.LOGO
*B 002 ALICE.SHAPES
*B 002 CHESHIRE.SHAPES
*B 002 CROC.SHAPES
*B 003 CROC1.AUX.LOGO
*B 002 CROC1.SHAPES
*B 004 DIS.LOGO
*B 002 FERRET2.SHAPES
*A 002 HELLO
*B 003 INITSHAPES.AUX.LOGO
*B 002 MUSIC.BIN
*B 004 MUSIC.SRC.LOGO
*B 002 QUEEN.SHAPES
*B 003 RABBIT.AUX.LOGO
*B 002 RABBIT.SHAPES

Now to make the disk be able to read
itself (remember, it still has the
original RWTS on it)... Not strictly
necessary, since the files can only be
loaded from within Krell's Logo, but
the original disk was self-booting, so
my copy should be, too.

Using Copy ][+, I can "copy DOS" from a
freshly initialized DOS 3.3 disk onto
the demuffin'd copy. This function of
Copy ][+ just sector-copies tracks 0-2
from one disk to another, but it's
easier than setting that up manually in
some other copy program.

Copy ][+
  --> COPY
    --> DOS
      --> from slot 6, drive 2
      -->   to slot 6, drive 1

[S6,D1=demuffin'd copy]
[S6,D2=newly formatted DOS 3.3 disk]

...read read read...
...write write write...

Quod erat liberandum.

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A 4am crack                      No. 77
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