The AT&T operating system distribution for Revision 3 (3B2/500, 3B2/600, and 3B2/1000) was distributed on 60MB SCSI cartridge tapes.
The format of this tape contains the following records:
- A bootable /unix
- A cpio archive of the /usr filesystem
- A list of packages in cpio format, as a single file named
- All remaining packages, as floppy diskette images
The Package List
The package list contains one line for each package, with fields
separated by a percent sign (
%) and spaces replaced by equal
=). For esxample:
Enhanced=Ports%1%3EM5%2%eports SCSI=Cartridge=Tape%1%3ST9%1%sctp Directory=and=File=Management%1%dfm%0%dfm User=Environment%1%usrenv%1%usrenv Terminal=Information-=part=1%1%termi1%0%terminfo1p Terminal=Information-=part=2%1%termi2%0%terminfo2p Line=Printer=Spooling%1%lp%0%lp Terminal=Filters%1%termfl%0%termflt Basic=Networking%2%bnu1%0%bnu ASSIST%3%assist%0%assist Windowing%1%window%1%windowing Editing%1%editor%0%editors Graphics%3%graph1%0%graph HELP%1%help%0%help Interprocess=Communications%1%ipc%1%ipc Performance=Measurement%1%perf%1%perf SPELL%1%spell%0%spell System=Administration%1%sysadm%0%sysadm System=Header=Files%1%syssys%0%syshdr
The fields are:
- Long package name
- Number of disks
- Floppy filesystem label
- Reboot flag (0 = no, 1 = yes)
- disk name
The Floppy Images
All of the floppy image files are the same size (1422 blocks) and can be
restored to a physical floppy with the
dd command under Linux.
Note, however, that these images cannot be used directly on the 3B2 emulator, because the emulator expects a disk image of exactly 1440 blocks. Why the discrepency? Because the last track on both sides of the floppy image is normally blank, so the images on the tape are 79 tracks by 2 sides by 9 sectors per track, while the emulator expects 80 tracks by 2 sides by 9 sectors per track.
You can easily fix this with
dd by copying the contents of the 1422
block image into a 1440 block image, for example:
The information on this page came directly from Steve Friedl’s 3B2 Tech Tips pages, and is preserved here for mirroring purposes.