logo.jpg

Burner (Mastertronic variant)

Structure

A regular CBM part, whose CBM data CRC32 is sometimes 0x53A23D4D. After turbo blocks there's another CBM part followed by additional turbo blocks. CBM Header stores vital loader data. It's encrypted the same way as legacy Burner. The XOR value is 0×59.

Turbo blocks

  • Threshold: 0×0180 (384) clock cycles (TAP value: 0×30)
  • Bit 0 pulse: 0×23
  • Bit 1 pulse: 0×42
  • Endianess: Varies per tape
  • Pilot byte: Varies per tape (size: 192 bytes)
  • Sync byte: Varies per tape

Header

  • 02 bytes: Load address (LSbF)
  • 02 bytes: End address (LSbF)

Data

  • 01 byte: EOF marker (when it's 0×00 it means end of a chain)
  • 02 bytes: Execution address (LSbF) (dummy value until the EOF marker is 0×00)
  • 02 bytes: Execution address repeated (last pulse of which is usually broken and is therefore NOT mandatory)

Trailer

  • None

Notes

Hardcoded inside CBM Header block:

  • $033C+$87 or $89: Pilot byte
  • $033C+$92 or $94: Sync byte
  • $033C+$82 or $84: ROR or ROL (Endianess is LSbF or MSbF respectively)

Tapes using this loader

Commented Loader Code

Place loader code here please.

See also


Personal Tools