perm filename CCA.BLA[ESS,JMC] blob
sn#147621 filedate 1975-02-25 generic text, type T, neo UTF8
Computer Corporation of America
Datacomputer File Transfer Program User's Guide
15 June 1974
The datacomputer is a shared large-scale data storage
utility offering data storage and data management services
to other computers on the Arpanet. The system is intended
to be used as a centralized facility for archiving data, for
sharing data among the various network hosts, and for
providing inexpensive on-line storage for sites needing to
supplement their local capability. The datacomputer is
implemented on dedicated hardware, and comprises a separate
computing system specialized for data management.
Logically, the system can be viewed as a closed box shared
by multiple external processors and accessed in a standard
notation called datalanguage.
The Datacomputer File Transfer Program (DFTP) is a
user-invoked program which runs on PDP-10 network sites, and
can store and retrieve local files on the datacomputer.
DFTP translates simple user commands into datalanguage which
is then sent to the datacomputer. The program receives and
processes the messages and data returned from the
datacomputer and notifies the user of the action taken.
DFTP also manages local file input/output and secondary
network connections to and from the datacomputer.
There are two versions of the program. One runs at
TENEX installations, the other at TOPS-10 sites with network
software similar to Harvard's. Files of any type (e.g.,
text, binary image) up to 500 TENEX pages (2000 TOPS-10
blocks) in size can be stored.
Each site running DFTP has a datacomputer directory
node. Each user with files on the datacomputer has a node
subordinate to his site node and equivalent to his TENEX
directory name or TOPS-10 programmer number. A user can
only access files subordinate to his datacomputer user node.
The user node name space is divided into subdirectories,
subordinate to which are individual files. Files are
accessed by establishing a subdirectory context - by
connecting to a subdirectory. A user can only be connected
to one subdirectory at a time. The user is initially
connected to his main subdirectory (which is automatically
created and is unpurgable).
The possible DFTP commands are:
(1) STORE <file name> (datacomputer synonym)
(2) RETRIEVE <file name> (local synonym)
(3) DELETE <file name>
(4) DIRECTORY (C) (S)
(5) CONNECT (subdirectory) (password)
(6) PURGE <subdirectory> (password)
(7) QUIT
Items in angle brackets are required arguments; items in
parentheses are optional ones.
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DFTP performs TENEX-like recognition of commands. The
command editing controls are also similar to TENEX:
<control-A> deletes a character
<control-R> retypes the line
<control-X> and <rubout> delete the line
<altmode> and <space> are separators
<carriage return>, <line feed> and <eol>
are terminators
The STORE command allows the user to store a TENEX or
TOPS-10 disk file on the datacomputer. The user may issue
the command in the form
STORE <file name>
where <file name> is a file on local disk and a legal
datacomputer file name. Datacomputer file names are strings
of up to 100 letters or digits. If the file name is not a
legal datacomputer file name, or if the user desires to give
the datacomputer file a name different from that of the the
local file, he must specify the command in the form
STORE <file name> <datacomputer synonym>.
If a file with the same name already exists on the
datacomputer, DFTP will respond
[OLD FILE] [CONFIRM].
A terminator confirms the command and overwrites the old
file with the new.
Similarly, The user may retrieve a file from the
datacomputer by saying
RETRIEVE <file name>
or
RETRIEVE <file name> <local synonym>
if he wishes to name the local file differently from the
datacomputer file.
The user may obtain a listing of all his datacomputer
files by using the DIRECTORY command.
DIRECTORY C
will give a complete listing of all subdirectories with
their respective files.
DIRECTORY S
will provide a listing of all subdirectory names.
DIRECTORY
(followed by a terminator) will list the user's current
subdirectory and files.
The CONNECT command accesses another subdirectory and
its subordinate files or creates a new subdirectory. The
user specifies the command in the form
CONNECT <subdirectory> (password).
If the subdirectory does not presently exist, DFTP will
notify the user that it is a new subdirectory and ask for
confirmation. If no passsword is specified, a null password
is assumed.
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A file may be deleted from the subdirectory currently
connected to through the command
DELETE <file name>.
An entire subdirectory may be deleted via
PURGE <subdirectory> (password).
The password argument must be omitted if the subdirectory to
be purged has a null password.
The QUIT command is used to exit from DFTP - it closes
the network connections with the datacomputer.
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A Sample DFTP Dialogue
[USER LOGIN]
*STORE FOO.SAV
[NEW FILE]
*RETRIEVE FOO.SAV
[OK]
*STORE FOO.SAV
[OLD FILE] [CONFIRM]
(A carriage return was supplied at this point.)
*DIRECTORY
CCA <HACKER>
MAIN SUBDIRECTORY
FOO.SAV 194 1-OCT-1973
*CONNECT EXAMPLE
[NEW SUBDIRECTORY] [CONFIRM]
(A carriage return was supplied at this point.)
*STORE -CHECKR.TECO CHECKER.TECO
[NEW FILE]
*DIRECTORY
CCA <HACKER>
EXAMPLE
CHECKER.TECO 94 13-APR-1973
*DIRECTORY (COMPLETE)
CCA <HACKER>
MAIN SUBDIRECTORY
FOO.SAV 194 1-OCT-1973
EXAMPLE (*)
CHECKER.TECO 94 13-APR-1973
*DIRECTORY (SUBDIRECTORIES)
CCA <HACKER>
MAIN SUBDIRECTORY
EXAMPLE (*)
*PURGE EXAMPLE
[CONNECTED TO MAIN SUBDIRECTORY]
*DIRECTORY (COMPLETE)
CCA <HACKER>
MAIN SUBDIRECTORY (*)
FOO.SAV 194 1-OCT-1973
*DELETE FOO.SAV
*DIRECTORY
CCA <HACKER>
MAIN SUBDIRECTORY
NO FILES
*QUIT
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Additional Information
There are a number of special DFTP commands not
necessary for common DFTP use. These functions are invoked
by first typing <control-S> at normal command level and then
a key character.
S and N stand for SHOW DATALANGUAGE and NO DATALANGUAGE
respectively. They set and clear the switch that routes
DFTP-datacomputer communication to the user's terminal.
TIME TRANSFERS and UNTIME TRANSFERS are indicated by T
and U. Timing transfers sends baud rates for data transfers
to the user.
A, for ATTACH, is used to connect to a new datacomputer
user node. The arguments of the command are:
<site>:<user>'<password>
DFTP provides security for both user nodes and
subdirectories.
Read and write privileges are determined at the user
node level. There are three user node privilege mechanisms:
1) implicit, automatic read-write access, 2) an explicit
read-write password, and 3) an explicit read-only password.
Read-write privilege is granted implicitly if the user
connects to the datacomputer from the proper host and socket
number. (The socket number is a function of the user's
local directory or programmer number). One may also connect
to a user node explicitly using the special ATTACH command,
in which case the privileges associated with the password
used (read-write or read-only) will be granted.
Subdirectory passwords control access to subdirectories
-- they are required by the CONNECT command. They do not
regulate privileges. These are inherited from the user
node.
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