Quick Release Sector Transfer
From Just Solve the File Format Problem
The QRST disc image format was used by Compaq to distribute disk images of diagnostic software. The file QRST.EXE would be supplied with the disc images to write them to a floppy drive.
Identification
QRST files start with the 4-character ASCII string QRST
, followed by a 0x00
byte. The first character of the file extension is an underscore, followed by a 2-digit hexadecimal volume number.