Jumpjet (Amstrad CPC)

Jumpjet
Publisher: Anirog Software Platform: Amstrad CPC Released in EU: 1985 This game has uncompiled source code. This game has anti-piracy features.

Anti-Piracy

This needs some investigation. Discuss ideas and findings on the talk page. Specifically: Method of activation.

If the game finds it has been hacked in any way, this message will display on the screen.

By the way, This is a naughty illegal
hacked copy, and as such cannot be
allowed to exist so it will self-
destruct in 60 seconds.

I suggest that you buy a proper copy,
and while your there get House of
Usher and Moonbuggy also by Anirog.

Source Fragments

Scattered throughout the disk are small bits of code.

0xFC3D:

TITLE "            LOADING CODE FOR JUMPJET
PLEN 66
NOLIST;LIST P
WIDTH 80
ORG &9000
LD A,128
LD (ST3),A
LD HL,&C000
LD DE,&C00
LD A,129
CALL LA1
LD HL,&CC00
LD DE,&C00
LD A,145
CALL LA1
LD HL,&D800
LD DE,&C00
LD A,243
CALL LA1
LD HL,&E400
LD DE,&C00
LD A,212
CALL LA1
LD HL,&F000
LD DE,&800
LD A,97
CALL LA1
LD HL,&F800
LD DE,&800
LD A,142
CALL LA1
LD HL,&2C00
LD DE,&C00
LD A,64
CALL LA1
LD HL,&3800
LD DE,&C00
LD A,149
CALL LA1
LD HL,&4400
LD DE,&C00
LD A,175
CALL LA1
LD HL,&5000
LD DE,&C00
LD A,234
CALL LA1
LD HL,&5C00
LD DE,&C00
LD A,197
CALL LA1
LD HL,&6800
LD DE,&C00
LD A,173
CALL LA1
LD HL,&7400
LD DE,&C00
LD A,130
CALL LA1
LD HL,&8000
LD DE,&800
LD A,219
CALL LA1
LD HL,&8800
LD DE,&658
LD A,167
CALL LA1
RET
.LA1
LD (ST1),HL
LD (ST2),DE
CALL &BCA1
LD A,53
LD (&40FF),A
CALL &BC68
JP C,LA2
LD A,(&B8CF)
.LA2
CP 74
JP Z,LA4
CP 73
JP Z,LA4
CP 75
JP Z,LA4
LD HL,&2C00
.LA3 LD (HL),0
INC HL
JP LA3
.LA4
LD HL,(ST1)
LD BC,(ST2)
LD A,(ST3)
INC A
LD (ST3),A
LD D,A
.LA5 LD A,(HL)
XOR D
LD (HL),A
INC HL
DEC BC
LD A,B
OR C
JP NZ,LA5
RET
.ST1 DW 0
.ST2 DW 0
.ST3 DB 0
DUMP
END

0x98A8:

 0
CALL Z,LQ0
LD A,(HL)
AND 128
SLA A
RLA
SLA A
SLA A
SUB 2
ADD A,C
LD C,A
LD H,0
LD L,C

0x9A00:

LD DE,140
OR A
SBC HL,DE
JP P,STOPS
LD A,C
CP 0
JP Z,STOPS
LD HL,(SSP)
DEC HL
DEC HL
DEC HL
DEC HL
LD (HL),B
DEC HL
LD (HL),C
IN