| Author: | Lord Crass (guest: search) |
|---|---|---|
| Date: | Sun, Mar 20th, 2011 @ 14:26 ( . ) |
Here's what it does: After the title screen, it reads track 16 sector 20 (which seems to be mostly empty), after the read the drive head is at the tail gap (normally $55 bytes). It reads until it gets a $6A byte, puts it in the $309 location in drive memory. Then it reads the next 4 bytes and puts them reversed at $305-$308. Standard GCR decode follows and data is sent to the C64. The C64 loads the data into $CB00, then EORs the 4 bytes it loaded together. Result must be $79 or reset occurs. Force the value for a crack (I didn't check for checksums or anything like that) and the program continues and asks you to insert side 2, which I don't have. Or fix the GCR bytes in the image so they EOR (after GCR decode) to $79, which shouldn't be too hard. BTW, the non-working bytes in the NIB dump you have are at offset $3DE97 and are: 6A 3D 5C D1 9F |
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