UNABLE TO LOAD GAME

DON'T LOOK NOW, BUT I THINK WE JUST FOUND THE COPY PROTECTION.

26FAL

26FA-   BD 89 C0    LDA   $C089,X
26FD-   A9 56       LDA   #$56
26FF-   85 11       STA   $11
2701-   D0 01       BNE   $2704
2703-   D0 C6       BNE   $26CB
2705-   12          ???

OH JOY, MORE OBFUSCATED CODE. THE "BNE" AT $0701 UNCONDITIONALLY BRANCHES INTO THE MIDDLE OF THE NEXT INSTRUCTION, WHICH CONFUSES THE MONITOR'S BUILT-IN DISASSEMBLER.

2703:EA
26FAL

26FA-   BD 89 C0    LDA   $C089,X
26FD-   A9 56       LDA   #$56
26FF-   85 11       STA   $11
2701-   D0 01       BNE   $2704
2703-   EA          NOP
2704-   C6 12       DEC   $12
2706-   F0 03       BEQ   $270B
2708-   D0 0A       BNE   $2714
270A-   D0 C6       BNE   $26D2
270C-   11 D0       ORA   ($D0),Y

OOPS, THERE'S ANOTHER ONE. $0706 IS A BRANCH TO $070B, WHICH IS SHOWN IN THE MIDDLE OF AN INSTRUCTION AGAIN.

270A:EA

I'LL SPARE YOU THE GORY DETAILS, BUT THERE ARE A FEW MORE OF THESE. JUST A FEW. 16. THERE ARE 16 MORE.

2713:EA
271B:EA
2722:EA
272A:EA
2731:EA
2739:EA
2740:EA
274A:EA
2751:EA
2754:EA
275E:EA
2766:EA
276E:EA
2776:EA
277D:EA
2786:EA

It goes on like this for like, days:

]PR#6
...offers input selection, then hangs with the drive motor on...

That's actually a lot of progress. I can now calibrate my joystick before the game tells me to go f--- myself.

~

Chapter 7
In Which I'd Like To Add You To My Professional Network Of Linked Catalog Sectors

Let's go back to that "unreadable" sector on track $11, the one that looks exactly like a DOS 3.3 catalog sector, because it is a DOS 3.3 catalog sector. It's just not linked into the VTOC.

T11,S00 currently points to T11,S0F as the first catalog sector, but all of the "files" in that catalog sector are fake. What if I changed it to point to sector $07 instead?

[...]

I'm beginning to suspect that this disk is nothing more than an infinite series of decryption routines with a game bolted on as an afterthought.