-------Customized Alphabet Drills------
A 4am crack                  2015-08-01
---------------------------------------

Name: Customized Alphabet Drills
Genre: educational
Year: 1981
Author: Jerome I. Weintraub
Publisher: Random House Micro-Line
  Programs
Media: single-sided 5.25-inch floppy
OS: DOS 3.3
Previous cracks: none
Identical cracks:
  Charlie Brown's 123's (crack no. 232)
  Charlie Brown's ABC's (crack no. 226)

                   ~

               Chapter 0
 In Which Various Automated Tools Fail
          In Interesting Ways


COPYA
  immediate disk read error

Locksmith Fast Disk Backup
  unable to read any track

EDD 4 bit copy (no sync, no count)
  copy works

Copy ][+ nibble editor
  all tracks use standard prologues
  (address: D5 AA 96, data: D5 AA AD)
  but modified address epilogue
  (AA DE EB instead of DE AA EB)

Disk Fixer
  ["O" -> "Input/Output Control"]
    set Address Epilogue to "AA DE EB"
  Success! All tracks readable!
  T00 -> looks like a DOS 3.3 RWTS
  T11 -> DOS 3.3 disk catalog
  T01,S09 -> startup program is "HELLO"

Why didn't COPYA work?
  modified epilogue bytes (every track)

Why didn't Locksmith FDB work?
  modified epilogue bytes (every track)

EDD worked. What does that tell us?
  probably just structural protection
  (modified epilogue), no nibble check

Next steps:

  1. capture RWTS with AUTOTRACE
  2. convert disk to standard format
     with Advanced Demuffin
  3. patch RWTS to read standard format

                   ~

               Chapter 1
In Which We Attempt To Use The Original
    Disk As A Weapon Against Itself


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

]BRUN ADVANCED DEMUFFIN 1.5

["5" to switch to slot 5]

["R" to load a new RWTS module]
  --> At $B8, load "RWTS" from drive 1

["6" to switch to slot 6]

["C" to convert disk]

                 --v--

ADVANCED DEMUFFIN 1.5    (C) 1983, 2014
ORIGINAL BY THE STACK    UPDATES BY 4AM
=======PRESS ANY KEY TO CONTINUE=======
TRK:...................................
+.5:
    0123456789ABCDEF0123456789ABCDEF012
SC0:...................................
SC1:...................................
SC2:...................................
SC3:...................................
SC4:...................................
SC5:...................................
SC6:...................................
SC7:...................................
SC8:...................................
SC9:...................................
SCA:...................................
SCB:...................................
SCC:...................................
SCD:...................................
SCE:...................................
SCF:...................................
=======================================
16SC $00,$00-$22,$0F BY1.0 S6,D1->S6,D2

                 --^--

]PR#5
]CATALOG,S6,D2

C1983 DSR^C#254
429 FREE

 A 002 HELLO
 A 029 ALPHA
*B 002 GS
*B 034 ALOGO

]RUN HELLO
...works...

[S6,D1=demuffin'd copy]

]PR#6
...grinds then crashes...

The demuffin'd disk can't read itself.
This is not unusual.

                   ~

               Chapter 2
 In Which We Remove All Traces Of Copy
Protection Using An Automated Tool That
   I Wrote For Just Such An Occasion


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

]PR#5
]BRUN PDP

; fix epilogue byte checking in RWTS
T00,S03,$91 change AA to DE
T00,S03,$9B change DE to AA
T00,S06,$AE change AA to DE
T00,S06,$B3 change DE to AA

Quod erat liberandum.

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A 4am crack                     No. 380
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