I (Landau) am working on this section on the Mac.

The tape formats supported by Gnosis will be limited. Fixed length records up to 4096 bytes in length and fixed blocked records up to 32768 byte blocks will be supported. Undefined records will be supported up to 4096 bytes in length. Variable and variable blocked records are supported for record lengths to 4096 and block lengths to 32768.

There exists a capability to a reel of tape (a set of reels for multivolume files). This capability is obtained from a librarian capability and may be called upon to change the default format of the tape, mount and dismount the tape, and to generate rescindable copies of the key. When a tape is mounted, there is a tape access key that can be called to open and close files on the tape and to read and write unblocked data to the tape.

A tape capability may be returned to the librarian for reallocation. There are techniques to claim a tape that has been imported from another system and to export a tape to another system. These latter two procedures involve a trusted human operator.

Librarian Function

This is the only public key involved in the Gnosis tape system. It is called to obtain a capability to a tape or to return it.

TAPELIB(kt ==> x'22b')

TAPELIB(0,(number of reels);SB,AC ==> c,((8,password));TAPEKEY) Allocate a tape.

The TAPEKEY returned has full capability to the non-privileged functions. Excluded are Mount Unverified, Unload tape, Set label type, and Write Label. "Number of reels" is specified as a 3 EBDIC digit decimal number between 1 and 400 inclusive.

"password" (EBDIC) may be used to reclaim a tape if the key is lost. Reclaiming a tape is a way of rescinding all outstanding tape keys without releasing the tape. Reclaiming can also be used after big bangs to reestablish the tape keys.

AC is an account key that will be billed for the tape and storage charges.

Return codes

c = 0 success

c = 1 insufficient number of tapes available

c = 8 account has insufficient funds

c = 9 Spacebank not good enough

TAPELIB(1;TAPEKEY,AC ==>c,) Release a tape.
TAPEKEY key must have release rights.

AC is an account that will be credited for the value of the tape. This is equivalent to TAPEKEY(kt+4). The space allocated for the TAPEKEY will be reclaimed. Any subordinate keys will be destroyed and their space reclaimed. Only if this key was obtained directly from the librarian will the tape be released for reuse.

Standard labels are written on the tape.

Return code

c = 0 released

c = 1 tape does not have release rights. Key destroyed.

TAPELIB(2,(8,password);SB,AC ==> c;TAPEKEY) Claim a tape.
Like TAPELIB(0) except that the tape was a foreign tape and the password was obtained from the trusted operator when the tape was presented or the tape is being reclaimed and the password is the one received when the tape was first allocated. The reclaiming operation destroys all existing tape keys and issues a new one.

This operation can be used to reconstruct TAPEKEYS after a "Big Bang" provided that the tape database is restored. The tape database contains keys only for allocated tapes. It contains textual information about the tapes and the passwords associated with them.

Return codes

c = 0 success

c = 1 password incorrect

c = 2 tape does not exist

c = 3 tape is part of multireel set

c = 4 incorrect password format (not 8 characters)

c = 8 account has insufficient funds

c = 9 Spacebank not good enough

TAPELIB(3,(n,external designator);TAPEKEY ==>c) Designate a tape to be exported.
The trusted operator is informed which reel is to be exported and what should be written on its paper label to identify it. The destination should be included in the designator. The capability to the tape is not lost.

Return codes

c = 0 success

c = 1 Tape key does not have export rights

c = 2 Unable to get TAPEOP key

c = 3 Unable to get builder key

c = 4 Unable to get DOMCRE key

c = 5 TAPEKEY is not a tape key

c = 6 TAPEKEY does not specify a single volume tape

TAPELIB(4,(DESCRIPTION);TAPEKEY ==>) associates the text DESCRIPTION with the reel in a way available to the tape operator.

TAPELIBP(kt ==> x'32b')

TAPELIBP(1,(6,reel) ==>c) make tape available (used by TAPEKEY).

When the TAPELIB(1) call is made, TAPELIB simply returns to the tapekey with ordercode kt+4 and the original caller. TAPEKEY dissolves and if it is the master key it calls TAPELIBP to make the tape available. This second entry is to avoid loops. Return codes are the same as TAPELIB(1).

Standard labels are written on the tape.

This key is related to the Librarian Function and is closely held by the administrator. It is another start key to the same domain as TAPELIB but with a different databyte value.

TAPEMAN(kt ==> x'12b')

TAPEMAN(0,(6,reel number)(n,external id); ==> c) introduce public tape.

A tape is mounted and a standard label is written on the tape. Reel number is a 6 byte string that will appear as the tape label. External id is an alphanumeric string of a descriptive nature.

Return codes

c = 0 tape added to library

c = 1 reel number not 6 characters

c = 2 tape reel number is not unique

c = 4 cant get tapekey to label tape

c = 5 mount failed

c = 6 label write failed

TAPEMAN(1,(6,reel number); ==> c) withdraw tape.
The tape is removed from the database. All TAPEKEYS that might exist are destroyed.

Return codes

c = 0 done

c = 1 reel number not 6 characters

c = 2 tape not in database

c = 3 reel is part of multireel set (not first)

TAPEMAN(2,(6,reel number)(n,external id); ==> c,(8,password)) introduce new private tape.
Works the same as TAPEMAN(0) except that the tape may only be claimed if the correct password is given on the CLAIM request.

Return codes

c = 0 done

c = 1 reel number not 6 characters (param string less than 6 characters)

c = 2 Reel number is not unique.

c = 4 can't get tapekey to label tape

c = 5 mount failed

c = 6 label write failed

TAPEMAN(3,(6,reel number)(n,external id); ==> c,(8,password)) introduce old private tape.
Works the same as TAPEMAN(0) except that the tape may only be claimed if the correct password is given on the CLAIM request.

When the TAPEKEY is constructed and issued to the claimant, the label is read. If standard label is found the tape is so marked. If no label is found the checksum of the first block becomes the verification.

Return codes

c = 0 done

c = 1 reel number not 6 characters

c = 2 Reel number is not unique.

The tape database is a named sequence record collection. In this collection is a record for each tape in the library. Tapes are either allocated or unallocated. If the tape is allocated the record contains the nodekey for the highest level TAPEKEY that was issued on a claim or allocation of the tape. There is no key in the record if the tape is available or unclaimed. If the key in the record is a zero data key then the tape is a part of a multivolume set and not the first volume of that set.

Record Format

Areel# (8,password),External information.
An available tape

Ureel# (8,password),External information NODEKEY or DK(0).
An unavailable tape

Preel# (8,password),External information NODEKEY or DK(0).
A private tape

There is also a password database that is used to insure that a password is never reused. It is also used to access tapes by password.

Record Format

Password,[A^U^P]reel#

Tape Access key

Tape Drive Allocation Operator level

This key allocates the specific drives in Gnosis and is responsible for determining that Gnosis has restarted. When Gnosis restarts, all access keys disappear. This key is available only to the TAPEKEY segment keeper. The REEL and NODEKEY are specified for historical reasons.

TAPEOPERF(0;sb,m,sb,,,COMMONNODE==>c;tapeop) - Create Tape Operator program (OS program, OSFLOAD TAPEOPERF TAPEOP akt COMMONNODE)

TAPEOP(0;SIK6,SOK6,CCKNODE ==>c) CCKNODE has CCK6 in slot 0. Run TAPEOPER program.

The TAPEOP program was designed to run in a CAM and as such has a rather baroque interface with the outside world. Significant components are ALLOCATE and MOUNTFILE which it uses to perform the tasks described under TAPEOPER. Implicit in this interface is the fact that COMMONNODE contains a directory key in slot 2 and that the key TAPEOPER is put into that directory under the name TAPEOP. I said it was baroque!!
MOUNTFILE is a named sequenced record collection with 2 record types. Records with a name of 2 bytes of the DRIVE ADDRESS record pending mounts and have a key of the TAPEKEY node key. The Resume key of the TAPEKEY object is in slot 7 of the node. Records with a 6 byte name are messages sent to the TAPEKEY via ordercode 10. Mount pending records are removed by the operator task that does the mount. Message records are removed by the Master Full Screen Tape Operator (p3,fstapop).

For a better understanding of this read the INSTTAPE CMDFILE and the CAM documentation.

TAPEOPER(kt ==> x'42b')

TAPEOPER(0,(6,reel);TAPEnodeKEY ==>
c;TAPEACCESS,TAPEACCESSDOMKEY) allocate a drive for a tape. The tape is mounted with no ring.

A drive is allocated and a TAPEACCESS key is constructed. TAPEACCESS is given the TAPEKEY node and will be able to read and write information into the node.

Return codes

c = 0 drive allocated

c = 1 no drives available

c = 2 tape is in use.

c = 3 mount refused by operator

TAPEOPER(1,(6,reel);TAPEnodeKEY ==>
c;TAPEACCESS,TAPEACCESSDOMKEY) allocate a drive for a tape. The tape is mounted with a ring.
A drive is allocated and a TAPEACCESS key is constructed. TAPEACCESS is given the TAPEKEY node and will be able to read and write information into the node.

Return codes

c = 0 drive allocated

c = 1 no drives available

c = 2 tape is in use.

c = 3 mount refused by operator

TAPEOPER(2,(6,reel); ==> c) deallocate the drive used by this tape (if mounted).
The drive is freed and all ACCESS keys are destroyed.

Return codes

c = 0 done

c = 1 tape not mounted

TAPEOPER(3,(6,reel); ==> c) deallocate the drive used by this tape and forget that the tape is mounted.
This is used during label verification if it is discovered that the label is incorrect. It is assumed that the operator mounted the wrong tape and must physically mount another.

Return codes

c = 0 done

c = 1 tape not mounted

TAPEOPER(4,(n,string) ==> 0) Send "string" as a message to the tape operator.

Design Notes

The function of order 4 on the tapelib key should be provided by a call on the tape key. This function would be subject to restriction.