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Network Working Group J. White
Request for Comments: 216 UCSB Computer Research Lab
Categories: D.3, G.3 September 1971
NIC: 7546
Telnet Access To UCSB's Online System
Contents
I. Motivation .................................................1
II. Limitations ................................................2
III. System Documentation .......................................2
IV. System Access ..............................................3
V. Software Structure .........................................3
VI. Virtual OLS Keyboard .......................................4
VII. NETOLS Commands ...........................................10
A. HELP ...................................................10
B. PREFIX .................................................10
C. SHIFT and UNSHIFT ......................................10
D. FULLDUPLEX and HALFDUPLEX ..............................10
E. STATE ..................................................11
F. LOGOUT .................................................11
VIII. OLS Display ...............................................11
IX. Instructing User Telnet ...................................12
X. Examples ..................................................14
A. Logon ..................................................14
B. Newton-Raphson Square Root Approximation ...............15
C. Remote Job Entry .......................................16
Figures
Figure 1. OLS Keyboard .............................................2
Figure 2. Keys With One-for-One Mappings ...........................6
Figure 3. Keys Represented as Strings ..............................7
Figure 4. Characters With One-for-One Mappings ....................12
Figure 5. Characters Which Map Into Strings .......................13
I. Motivation
A teletype-compatible interface to UCSB's Online System (OLS) has
been implemented in accordance with the Telnet protocol adopted by
the NWG. This Server Telnet is responsive to connection requests
directed by User Telnet's to socket number 1, host address 3.
Although OLS is not a teletype system and although much of its power
as mathematical tool rests in its graphical display capabilities,
enough of the System survives the Telnet transformation to justify
such an implementation.
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RFC 216 Telnet Access To UCSB's On-Line System September 1971
II. Limitations
In this Telnet-style implementation of OLS, all curvilinear display
generated by the user on Levels II and III, Real and Complex, is
disregarded by the System and hence not returned to the user through
the Net. The same is true of the display of special, user-created
characters. Although special characters may be constructed and
stored, their display will be suppressed, both during the process of
construction and later when they are invoked from the Type level.
All other display generated by the System will be relayed to the user
intact, in some cases with stylistic transformation having first been
applied. For example, Greek characters are displayed as lower-case
a-z. All such transformations are described in detail in this
document. Finally, those elements of the System (the operators which
edit user programs are prime examples) which assume a fixed-screen
display device function abnormally in a Telnet environment. For such
a device, the System can "remember" the position on the screen of a
previously displayed segment of text and return to that position to,
for example, underscore it. But when the "screen" marches forward --
relentlessly -- through a continuous medium, as it does with Telnet's
virtual teletype, that kind of strategy fails. Hence, the
underscoring is not relocated, but rather appears on the current
line, beginning in the next available character frame.
OLS assumes, normally, that the user is equipped with the specially-
designed double keyboard depicted in Figure 1. Conventions are
defined in this document, which enable a Telnet user to simulate that
keyboard; in particular, a means is provided for designating keys on
the upper, or operator keyboard.
III. System Documentation
This document has three purposes:
Figure 1. OLS Keyboard. [Please view the PDF version of this RFC.]
(1) to describe the means by which a Telnet user simulates an OLS
keyboard,
(2) to describe the transformations applied to output generated by
the System, and
(3) to enumerate those aspects of the System, which are unique to or
behave differently for Network (Telnet) users.
In particular, this document is not a user's manual for OLS. Such a
manual is available and on file with the NIC. In addition, a copy
should exist at each Network site in its NIC collection; the user
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RFC 216 Telnet Access To UCSB's On-Line System September 1971
should consult his Station Agent. This document is titled "UCSB On-
Line System Manual" [NIC 5748]; its contents are current as of 1
January 71. A revision to the manual is currently in preparation and
will be distributed when available. In addition, tutorial manuals
for two of the subsystems available under OLS-MOLSF (Mathematically-
Oriented Language Single-Precision Floating-Point) and COL (Card
Oriented Language) -- will soon be made available. The latter has
already been published and is being transmitted to the NIC for
distribution, while the former is nearing completion.
Documentation of the third subsystem of OLS--NET-- has already been
distributed through the NIC as two RFC's: "Network On-Line Operators"
[21 April 71, RFC 121, NIC 5833] and "A User Telnet--Description of
an Initial Implementation" [9 August 71, RFC 206, NIC 7176]. Net
currently houses a set of operators for system-call-level interaction
with UCSB's NCP, a User Telnet, and an operator (invoked by ID on
Level II), which returns the status of Network hosts.
Staff members at the Computer Center will be happy to field questions
about OLS from Network users. In particular, an OLS consultant is
available for such purposes at (805) 961-4044. Questions about OLS,
including those specific to use of the System through the Network,
may also be addressed to Jim White, UCSB's Technical Liaison, at
(805) 961-3454 (if necessary, messages can be left at the Computer
Center Office, (805) 961- 2261).
IV. System Access
The Network user is encouraged to explore the System and is invited
to do so with the following accounting parameters:
User Number: 196
Id Number: 57372
User Name: ARPA
Problem Name: (affiliation)-(name)
in 16 characters or less
(e.g., UCSB-White)
Such use of the System will not be billed. Production users are
asked to establish their own accounts with the Computer Center ((805)
961-2261), the use of which will be billed in accordance with the
then-current rate structure.
V. Software Structure
This document is the description of a Network front-end to the Online
System, logically distinct from OLS itself. This front-end is
hereafter referred to as NETOLS. NETOLS is always responsive to
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RFC 216 Telnet Access To UCSB's On-Line System September 1971
connection requests direct4ed to socket 1. When contacted by a
Network user, NTCLS performs the Network functions required to
establish a duplex connection to him. The number of such duplex
connections (and hence the number of Network users) is bounded by an
assembly parameter whose current value is five.
Before the Network connection is established, NETOLS secures for the
user a port into OLS. Sixty-four such ports exist and are shared by
local, dial-up, and Network users. Should none be available, NETOLS
will abort the connection sequence.
Once a port has been secured and a Network connection established,
NETOLS will effectively push the _SYST_ key for the user by
transmitting to OLS the 8-bit code representing that key. A login
sequence is thus initiated and the user is transmitted the lines:
UCSB ON-LINE SYSTEM
ENTER USER NUBMER
to which he should respond with his user number. Beginning at this
point in time and continuing for the life of the Network connection,
NETOLS's sole function is that of interpreter--interpreting input
from the user and making it meaningful to the user (it is at this
point, for example, that curvilinear and special-character display
are discarded).
When the user breaks his Network connection to NETOLS, if eh hasn't
logged out of OLS already, NETOLS performs that function for him by
pushing_ SYST_ _DOWN_, just as it pushed the initial _SYST_. The OLS
port acquired for the user is then released, and hence available for
use by other users. It should be noted that the user can log out of
OLS and back on again without the Network connection's being broken,
since that action is transparent to NETOLS, who attaches no special
significance to the Key sequence, which accomplishes it.
VI. Virtual OLS Keyboard
A major function of NETOLS is to provide a mapping between elements
of the Telnet character set and the keys on an OLS keyboard (Figure
1). The lower, or operand portion of that keyboard is fairly easily
represented, since it's similar to a standard typewriter keyboard.
Most of the keys on the lower keyboard are mapped on a one-for-one
basis from elements of the Telnet character set. Upper-case
alphabetics are mapped into the alphabetics, lower-case, and
miscellany of punctuation into itself. All such one-for-one mappings
are depicted in Figure 2. A line of that figure reads as follows:
For ['half arrow' - see the PDF version of this RFC]:
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RFC 216 Telnet Access To UCSB's On-Line System September 1971
The key labeled ['half arrow'] (meaning logical not) on the lower
portion of an OLS keyboard is struck by causing the user's User
Telnet to transmit '~' (tilde).
Those lower-keyboard keys not listed in Figure 2, and _all_ the keys
on the upper- keyboard (hereafter referred to collectively as _non-
standard_ keys), are represented by the Telnet user in the following
manner. For each such key, a character string has been defined; the
string is called the _name_ of the key. In most cases, the name of a
key is identical to its label in Figure 1. The name of the _SIN_
key, for example, is 'SIN (in the Online System User's Manual,
upper-keyboard keys are denoted by underscoring their labels, to
distinguish, for example, the key _SIN_ from the three keys 'SIN').
Every non-standard key on the OLS keyboard is struck by typing its
name (or any unique abbreviation thereof), preceded by a special
_prefix_ character and followed by a space.
NETOLS interprets the prefix, name, and space from them generates a
single, 8-bit code, which forwards to OLS.
The default prefix character is semi-colon (';'), chosen simply
because for touch typists it's one of the home keys. The prefix can
be changed by the user to any character listed in Figure 2. The
procedure for so doing is described in Section VII-B. To send the
prefix character through NETOLS to OLS, type it twice in succession.
Thus, if the default prefix is in effect, ';;' is mapped into a
single semi-colon and relayed to OLS.
The names of all non-standard keys are listed in Figure 3. A line of
that figure reads as follows:
For _SIN_:
They key denoted _SIN_ in the OLS User's Manual (the trigonometric
function sine) is named 'SIN', and hence is struck by typing
'SIN', preceded by the prefix and followed by a space.
Assuming, then, that the default prefix ';' is in effect, SIN is
struck by ';SIN_' ('_' is used here and in following examples to
denote a space). Furthermore, if the user chooses, he may abbreviate
that as ';SI_', since the key desired remains uniquely identified.
Further abbreviation (to ';S_') is unsatisfactory and hence
disallowed since the single character 'S' is insufficient to
distinguish between a number of keys whose names begin with that
character. Key names may be typed by the user in either upper- or
lower-case.
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RFC 216 Telnet Access To UCSB's On-Line System September 1971
As each character of a non-standard key's name is typed by the user,
NETOLS consults it table of key names. If the character string so
far specified cannot possibly lead to a valid name, the most recent
character is ignored ('?' echoed). Hence, typing ';SJIN_' will be
accepted as _SIN_, the erroneous 'J' being ignored (and a question
mark echoed), and the subsequent 'JN_' accepted. If when the
terminating space is typed, no single key is uniquely identified a
'?' is echoed and the space ignored. Thus, ';S_I_' will be
recognized as _SIN_; the first space is
To Push (OLS Explanation) Send (Telnet Explanation)
0-9 Decimal Digits 0-9 Decimal Digits
A-Z Alphabetics A-Z UC Alphabetics
_-5 Greek Characters a-z LS Alphabetics
! Exclamation Mark ! Exclamation Mark
+ Plus Sign + Plus Sign
_ Underscore _ Underscore
- Minus Sign - Minus Sign
@ Commercial At @ Commercial At
/ Slash / Slant
# Number Sign # Number Sign
' Apostrophe ' Apostrophe
& Ampersand & Ampersand
$ Dollar Sign $ Dollar Sign