💾 Archived View for mirrors.apple2.org.za › active › 4am › images › games › action › Rampage%20(4am%… captured on 2023-05-24 at 23:04:26.
⬅️ Previous capture (2023-01-29)
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----------------Rampage---------------- A 4am crack 2014-05-04 --------------------------------------- Rampage is a 1988 arcade game distributed by Activision, Inc. COPYA copies the original disk, but the copy does not work. It loads the (double hi-res!) title screen, then glitches out and reboots. The boot does not sound like DOS 3.3, ProDOS, or Pascal, and there is no evidence of any known file system on the disk. (I checked T11,S0F for signs of a DOS 3.3 catalog, then T00,S0B for ProDOS or Pascal.) With nothing else to go on, it's time for boot tracing. [S6D1=original disk] [S5D1=my work disk] ]PR#5 ... CAPTURING BOOT0 ...reboots slot 6... ...reboots slot 5... SAVING BOOT0 My AUTOTRACE program can capture the boot0 code on T00,S00, boot1 code on T00,S00-09 if boot0 is close enough to DOS 3.3, and even the RWTS (again, if boot1 is close enough to DOS 3.3). In this case, it only got as far as boot0, which means this boot code is probably completely unlike DOS 3.3. AUTOTRACE relocates the boot0 code to $2800..$28FF so it can survive the reboot, so let's see what we have. ]CALL-151 *800<2800.28FFM *801L ; looks like we're going to be loading ; boot1 starting at $8000. (Normal DOS ; 3.3 boot0 code starts with a branch ; like this as a way of determining ; whether it's done its one-time ; initialization yet, but it checks for ; #$09 instead of #$80.) 0801- A5 27 LDA $27 0803- C9 80 CMP #$80 0805- B0 52 BCS $0859 ; Zero page $2B has the slot number x ; 16 at this point. Store it in $0100? ; Odd. Noted for future reference. 0807- A5 2B LDA $2B 0809- 8D 00 01 STA $0100 ; figure out where the sector read ; routine is in the disk controller ROM ; based on the slot number we booted ; from. If we're booting from slot 6, ; this will end up being $C65C. 080C- 4A LSR 080D- 4A LSR 080E- 4A LSR 080F- 4A LSR 0810- 09 C0 ORA #$C0 0812- 85 3F STA $3F 0814- 8D 3C 08 STA $083C 0817- A9 5C LDA #$5C 0819- 85 3E STA $3E ; never seen this before, but it seems ; to always be zero, therefore branch 081B- A0 A3 LDY #$A3 081D- B1 3E LDA ($3E),Y 081F- F0 30 BEQ $0851 ... ; loop to re-use the disk controller ; ROM routine to read the rest of track ; 0 into $8000..$8FFF 0851- A9 80 LDA #$80 0853- 85 27 STA $27 0855- A9 FF LDA #$FF 0857- 85 3D STA $3D 0859- A5 3D LDA $3D 085B- 18 CLC 085C- 69 01 ADC #$01 085E- C9 10 CMP #$10 0860- 90 06 BCC $0868 0862- C9 11 CMP #$11 0864- F0 07 BEQ $086D 0866- A9 01 LDA #$01 0868- 85 3D STA $3D 086A- 6C 3E 00 JMP ($003E) ; execution continues at code we just ; read in from one of the other sectors 086D- 4C 70 80 JMP $8070 OK, that looks like a good place to interrupt the boot process and see what's going on. *9600<C600.C6FFM ; set up callback after reading all the ; sectors from track 0 96F8- A9 4C LDA #$4C 96FA- 8D 6D 08 STA $086D 96FD- A9 0A LDA #$0A 96FF- 8D 6E 08 STA $086E 9702- A9 97 LDA #$97 9704- 8D 6F 08 STA $086F ; start the boot 9707- 4C 01 08 JMP $0801 ; callback is here -- ; capture the boot1 code and reboot 970A- A2 10 LDX #$10 970C- B9 00 80 LDA $8000,Y 970F- 99 00 20 STA $2000,Y 9712- C8 INY 9713- D0 F7 BNE $970C 9715- EE 0E 97 INC $970E 9718- EE 11 97 INC $9711 971B- CA DEX 971C- D0 EE BNE $970C 971E- AD E8 C0 LDA $C0E8 9721- 4C 00 C5 JMP $C500 *BSAVE TRACE1,A$9600,L$124 *9600G ...reboots slot 6... ...reboots slot 5... ]BSAVE BOOT1,A$2000,L$1000 ]CALL -151 *8000<2000.2FFFM What evil awaits us in boot1? *8070L 8070- 8D 01 01 STA $0101 8073- A2 FE LDX #$FE 8075- 9A TXS ; test for 128K 8076- 8D 09 C0 STA $C009 8079- A9 4B LDA #$4B 807B- 85 00 STA $00 807D- C5 00 CMP $00 807F- D0 08 BNE $8089 8081- 49 FF EOR #$FF 8083- 85 00 STA $00 8085- C5 00 CMP $00 8087- F0 24 BEQ $80AD ; print "128K REQUIRED" and fail 8089- 8D 08 C0 STA $C008 808C- 20 58 FC JSR $FC58 808F- A2 0C LDX #$0C 8091- BD 9F 80 LDA $809F,X 8094- 09 80 ORA #$80 8096- 9D B5 05 STA $05B5,X 8099- CA DEX 809A- 10 F5 BPL $8091 809C- 4C 8B 82 JMP $828B ; 128K test passed, execution continues 80AD- 8D 08 C0 STA $C008 80B0- 2C 89 C0 BIT $C089 80B3- 2C 89 C0 BIT $C089 80B6- AD 01 01 LDA $0101 ; $0101 is #$11 at this point, so this ; branch is always taken 80B9- D0 11 BNE $80CC *80CCL ; relocate code from $83A0 to $D000 80CC- A9 A0 LDA #$A0 80CE- 85 FC STA $FC 80D0- A9 83 LDA #$83 80D2- 85 FD STA $FD 80D4- A9 00 LDA #$00 80D6- 85 FA STA $FA 80D8- A9 D0 LDA #$D0 80DA- 85 FB STA $FB 80DC- A2 07 LDX #$07 80DE- A0 00 LDY #$00 80E0- B1 FC LDA ($FC),Y 80E2- 91 FA STA ($FA),Y 80E4- C8 INY 80E5- D0 F9 BNE $80E0 80E7- E6 FD INC $FD 80E9- E6 FB INC $FB 80EB- CA DEX 80EC- D0 F2 BNE $80E0 From a quick inspection, $83A0 appears to be the entry point to an RWTS of some kind, and now it's at $D000 (in the language card). 80EE- 2C 8B C0 BIT $C08B 80F1- 2C 8B C0 BIT $C08B 80F4- A9 01 LDA #$01 80F6- 85 42 STA $42 80F8- AD 00 01 LDA $0100 80FB- 85 43 STA $43 80FD- A9 00 LDA #$00 80FF- 85 44 STA $44 8101- 85 47 STA $47 8103- A9 40 LDA #$40 8105- 85 45 STA $45 8107- A9 08 LDA #$08 8109- 85 46 STA $46 810B- A9 02 LDA #$02 810D- 85 FE STA $FE 810F- A9 10 LDA #$10 8111- 85 FF STA $FF ; call RWTS 8113- 20 00 D0 JSR $D000 8116- 90 03 BCC $811B 8118- 4C 8B 82 JMP $828B ; loop to read multiple sectors from ; multiple tracks 811B- E6 45 INC $45 811D- E6 45 INC $45 811F- E6 46 INC $46 8121- C6 FF DEC $FF 8123- D0 EE BNE $8113 8125- A9 20 LDA #$20 8127- 85 45 STA $45 8129- C6 FE DEC $FE 812B- D0 E2 BNE $810F ; copy half of double hi-res title ; screen to extended memory 812D- 8D 05 C0 STA $C005 8130- A9 00 LDA #$00 8132- 85 FC STA $FC 8134- A9 40 LDA #$40 8136- 85 FD STA $FD 8138- A9 00 LDA #$00 813A- 85 FA STA $FA 813C- A9 20 LDA #$20 813E- 85 FB STA $FB 8140- A2 20 LDX #$20 8142- A0 00 LDY #$00 8144- B1 FC LDA ($FC),Y 8146- 91 FA STA ($FA),Y 8148- C8 INY 8149- D0 F9 BNE $8144 814B- E6 FD INC $FD 814D- E6 FB INC $FB 814F- CA DEX 8150- D0 F2 BNE $8144 ; display double hi-res title screen 8152- 8D 04 C0 STA $C004 8155- 8D 5E C0 STA $C05E 8158- 8D 0D C0 STA $C00D 815B- 8D 00 C0 STA $C000 815E- 2C 50 C0 BIT $C050 8161- 2C 52 C0 BIT $C052 8164- 2C 57 C0 BIT $C057 8167- 2C 54 C0 BIT $C054 OK, my (non-working) copy did get this far, because it successfully displayed the double hi-res title screen. The glitching and rebooting and whatnot happened after this point. ; branch based on the value of $0101 ; (always taken) 816A- A2 00 LDX #$00 816C- A0 00 LDY #$00 816E- AD 01 01 LDA $0101 8171- D0 04 BNE $8177 *8177L ; more disk reads 8177- 86 46 STX $46 8179- 84 47 STY $47 817B- A9 01 LDA #$01 817D- 85 42 STA $42 817F- AD 00 01 LDA $0100 8182- 85 43 STA $43 8184- A9 00 LDA #$00 8186- 85 44 STA $44 8188- A9 08 LDA #$08 818A- 85 45 STA $45 818C- 20 00 D0 JSR $D000 ; Hmm, another branch based on $0101. ; Educated guess about the purpose of ; $0101: this code stays in memory and ; can be run more than once. When it's ; run for the second time, a bunch of ; stuff is still in memory so it can ; skip re-reading it from disk. The ; first time around, the value is #$11 ; (the last value set in boot0). 818F- AD 01 01 LDA $0101 8192- D0 05 BNE $8199 ; not executed (at least during boot) 8194- B0 0D BCS $81A3 8196- 4C 8B 82 JMP $828B ; execution continues here 8199- A9 00 LDA #$00 819B- 85 FC STA $FC 819D- AE 00 01 LDX $0100 81A0- 20 3E 82 JSR $823E *823EL ; manually turning on disk motor is ; always suspicious 823E- BD 89 C0 LDA $C089,X 8241- A9 56 LDA #$56 8243- 85 FD STA $FD 8245- A9 08 LDA #$08 8247- C6 FC DEC $FC 8249- D0 04 BNE $824F 824B- C6 FD DEC $FD ; this address looks familiar -- yup, ; it's The Badlands again (the code ; from which there is no return) 824D- F0 3C BEQ $828B ; nibble check 824F- BC 8C C0 LDY $C08C,X 8252- 10 FB BPL $824F 8254- C0 FB CPY #$FB 8256- D0 ED BNE $8245 8258- F0 00 BEQ $825A 825A- EA NOP 825B- EA NOP 825C- BC 8C C0 LDY $C08C,X 825F- C0 08 CPY #$08 8261- 2A ROL 8262- B0 0B BCS $826F 8264- BC 8C C0 LDY $C08C,X 8267- 10 FB BPL $8264 8269- C0 FF CPY #$FF 826B- D0 D8 BNE $8245 826D- F0 EB BEQ $825A 826F- BC 8C C0 LDY $C08C,X 8272- 10 FB BPL $826F 8274- 84 FC STY $FC 8276- C9 0A CMP #$0A 8278- D0 CB BNE $8245 827A- BD 8C C0 LDA $C08C,X 827D- 10 FB BPL $827A 827F- 38 SEC 8280- 2A ROL 8281- 25 FC AND $FC 8283- 49 FF EOR #$FF 8285- D0 04 BNE $828B ; nibble check passed ; turn off disk motor and exit 8287- DD 88 C0 CMP $C088,X 828A- 60 RTS ; nibble check failed ; wipe memory and reboot 828B- A8 TAY 828C- DD 88 C0 CMP $C088,X 828F- 68 PLA 8290- 68 PLA 8291- 99 00 08 STA $0800,Y 8294- C8 INY 8295- D0 FA BNE $8291 8297- EE 93 82 INC $8293 829A- AD 93 82 LDA $8293 829D- C9 82 CMP #$82 829F- D0 F0 BNE $8291 82A1- 2C 81 C0 BIT $C081 82A4- 2C 81 C0 BIT $C081 82A7- 6C F2 03 JMP ($03F2) Jackpot! Just your garden variety nibble check. If it succeeds, it just returns gracefully; it doesn't set flags, doesn't set memory, doesn't even say "thank you." And if it fails, it wipes most of main memory and reboots. That means I should be able to put an "RTS" at the beginning of it ($823E) to bypass the entire thing. T00,S0D,$3E change "BD" to "60" Quod erat liberandum. --------------------------------------- A 4am crack No. 28 ------------------EOF------------------