This firmware is likely for a MIPS (big-endian) or ARM (little-endian) processor. Do not attempt to run any binaries inside on your x86_64 laptop. They will not execute. Instead, use binwalk (a firmware analysis tool) to scan the tarball:
binwalk a145fw.tar
This reveals hidden compressed filesystems and executable code. a145fw.tar
Why would a modern security researcher care about a dusty file like a145fw.tar? Two words: vulnerability research. This firmware is likely for a MIPS (big-endian)
A .tar file is a type of compressed archive file that is commonly used in Unix and Linux operating systems. The .tar format is used for archiving files, and it bundles multiple files into one file for easier distribution and storage. The name "tar" comes from "tape archive," reflecting its origins in the early days of computing when data was often stored on magnetic tapes. a145fw.tar
mv a145fw.tar a145fw.tar.bz2 && tar -xjvf a145fw.tar.bz2