...
After this comes the next file. A tape is ended with two consecutive tape marks. (BUT! this is just a sofware software convention; there may be more data after this.)
...
- Open up the terminal in BitCurator
Navigate to the folder containing the itstar program
- Construct the command you'll use to extract the files.
The first time(s) we run the command we will use the "t" option to only print to the terminal what files would be extracted by the command. This will help when determining the other options to use.
"f" incicates we are using a tape image file, not reading from a tape itself.
The .tap files are not all encoded the same way, and there's no telling how a particular file is encoded except either 1) look at the byte codes inside, or 2) trial and error. We will use trial and error first (with the "t" option passed for print only).
-E is for using the E-11 tape image format or even-sized tape records
Big or little endian record size. Detault is little, pass -B for big.
9 or 7 track tapes. 9-track stores eight bits per byte. 7-track store 6 bits plus parity. Default is 9, pass -7 for the latter.
Two of the most common are "-7B": 7-track tape with big endian record sizes. Or just -E for 9-track little endian with an even-sized tape record.
Code Block language bash # Basic elements of the command $ itstar -t[tape encoding options] -C /path/where/you/want/the/extracted/files/to/go -f /path/to/tape/image.tap # Example of 7-track tape with big endian record sizes $ itstar -t7B -C /path/where/you/want/the/extracted/files/to/go -f /path/to/tape/image.tap # 9-track little endian with an even-sized tape record $ itstar -tE -C /path/where/you/want/the/extracted/files/to/go -f /path/to/tape/image.tap
Replace the t in the command with an x in order to extract the files.
tapeutils
tapeutils is a set of tools for creating and working with various types of tape images. We use the tapex program within tapeutils for extracting files from the TOPS-20 images that are found within the ToTS dataset