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Accolade/EA loader

Structure

After the CBM boot file, there is another CBM file that contains the main turbo loader.

Turbo blocks

  • 0x01EA (490) clock cycles (TAP value: 0x3D)
  • Bit 0 pulse: 0×29
  • Bit 1 pulse: 0x4A
  • Endianess: MSbF
  • Pilot byte: 0x0F (size: 8 bytes)
  • Sync byte: 0xAA

Header

  • 16 bytes: Filename
  • 02 bytes: Load address (LSBF)
  • 02 bytes: Data size (LSBF)
  • 01 byte : XOR Checksum of all Header bytes

Data

  • Data is split in sub-blocks of 256 bytes each, or less for the last one.
  • Each sub-block is followed by its XOR checksum byte.
  • There are no pauses between sub-blocks.

Trailer

  • 8 Bit 0 pulses + 1 longer pulse.

Notes

  • A variant has Threshold: 0x01A9 (425) clock cycles, but uses the same pulsewidths, more or less. It's often used in EA releases (whose first CBM Data block CRC32 is sometimes 0xEA684D09).
  • The name of the author was found in “Apollo 18”.

Tapes using this loader

Commented Loader Code

Place loader code here please.

See also


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