Commodore 64: Flashload loader

@DrWatson

Published in 

C64 tape formats

 · 3 years ago

Found on..

• Ghostbusters
• Hacker
• On Court Tennis
• Rock n Bolt.

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Threshold : $0118 (280) clock cycles (TAP value: $22).
Bit 0 : $1F
Bit 1 : $31
Endianess : MSbF
Pilot : Bit 1 pulses (*2048) with last one being bit 0.
Sync byte : $33

Then...

2 bytes : Load address (LSBF)
2 bytes : End address (LSBF)
n bytes : Data
1 byte : Checksum (0 XOR all data bytes)

Notes:

• Tapes always have an extra ROM Data block (pair), this contains the loader code.
• Loader is protected against Cartridges and Drives.