On 5/11/12 12:41 AM, Jochen Kunz wrote:
  BTW: I have a cardboard box with documentation for my
8560.
 
I only have volume 1 of the user's manual. I'm guessing there must have
been other volumes. I can see there is a man(5) page for fbr on the first
disk of the system restore which describes the format.
8560 MUSDU System Reference Manual                                   FBR(5)
___________________________________________________________________________
FBR(5)
NAME
      fbr - file backup and restore format
SYNTAX
      #include <sys/types.h>
      #include <fbr.h>
DESCRIPTION
      Fbr saves and restores directories and files on a floppy disk archive,
      preserving  aliases  (multiple  links  to the same file).  The archive
      consists of:
           Boot block - Block zero is reserved for a copy of  a stand-alone
           boot program.
           Directory area - This area contains directory information for all
           files  and  directories  on the archive.  The first entry in this
           area is dedicated to the archive label.
           Data area - The data of all files on the archive is stored here.
      The format of a directory entry (as given in the  include  file)  fol-
      lows.  To increase the portability of archives, this structure is read
      and written in PDP-11 format regardless of what machine fbr_is running
      on.
      #define PATHLEN         106     /* space for path       */
      struct fbrent
      {
              char            fbr_path[PATHLEN]; /* pathname  */
              unsigned short  fbr_mode;
              short           fbr_uid;  /* owner's userI^AD     */
              short           fbr_gid;  /* owner's groupID    */
              off_t           fbr_size; /* size in bytes      */
              time_t          fbr_acct; /* access date-time   */
              time_t          fbr_modt; /* modify date-time   */
              unsigned        fbr_fblk; /* firs^At       data block   */
              char            fbr_zero; /* unused             */
              char            fbr_chks; /* checksum           */
      };
      The path field is the pathname of the file  when  archived,  less  any
      redundant slashes or initial './'.  It is null-terminated if less than
      PATHLEN bytes long.  The mode, uid, gid, size, and access and  modifi-
      cation date-times are in the same format as their corresponding i-node
      fields.  As in the file system, an available entry has a mode of zero.
      The fblk field contains the block number of the first data block allo-
      cated to this file.  The zero field is  unused.   The  checksum  field
      contains  a  number  such  that  the sum of the first 127 bytes of the
                                                                           1
FBR(5)                                   8560 MUSDU System Reference Manual
___________________________________________________________________________
      directory entry and the complement of  the  checksum  is  zero.   Each
      file's  data  starts  on  a block boundary and occupies max(1,((size +
      511) / 512) contiguous blocks.  At least one archive  block  is  allo-
      cated  to  each  archived  file or directory so that aliases (multiple
      links) can be properly recorded.  Each directory archived  is  treated
      as  an  empty  file (I.E. no directory's data is stored).  All entries
      representing links to a given file are identical.  In particular,  the
      fblk field in each link's entry contains the same block number.
      The archive label directory entry contains the following information:
      path A comment about this archive.
      mode Set by fbr to a file readable/writeable/executable by all. Other-
           wise unused.
      uid  The userID of the user who created this archive.
      gid  The groupID of the same.
      size The total number of bytes in the data       area of the archive.   This
           field  in  combination  with  the fblk field,     records the size of
           both the directory area and the entire archive.
      acct The date-time that this archive was  created  -  not       its  access
           time.
      modt The date-time that this archive was last altered.
      fblk The block number of the first archive block following the  direc-
           tory area.
      checksum
           (same as any other directory entry.)
SEE_ALSO
    fbr(1), stat(2).
---
I'll be adding scans of the installation and service manual for the 8560
to bitsavers later today. Dug back though the Tek stuff I had bought a
while ago, and I have an 8562 (11/73 cpu) and a 8501. Don't have any docs
for those. The 8562 appears to use an I/O board with an 80186 instead of
the 8088, and a Micropolis 5" drive.