Quantum DLT 4000 Product Manual page 147

Firmware Update (From Tape)
When making the update tape, copy the image file to the tape media using a block size
as defined in Table 7-1, that is dd, ltf, and so forth. The tape has to be uncompressed.
DLT4000/DLT4500/DLT4700 Cartridge Tape Subsystem 7-5