User`s manual

4,291,198
5
associated keys. Accordingly, it has been found to be
advantageous in one embodiment to dedicate a key to
each such action option type and leave the screen-line
associated keys 16 for other line-associated selections
that are unique to a particular display. The keys 16 and
23 are sometimes called “soft keys" because they permit
the telephone station set user to exercise speci?c control
over the direction of execution of a computer-based
process in which the set is engaged.
The keyboard 20 advantageously includes more than
enough keys to produce a full set of character codes
according to the recommended USA Standard Code for
Information Interchange (ASCII), e.g., the 128 different
codes representing numerals, letters, and various func
tions which can be signaled from the keyboard to the
station set processor using upper and lower case key
functions and certain predetermined combinations of
key actuations as is well known in the art for ASCII
keyboards. Textual characters corresponding to actua
tions of these keys are displayed on the screen, and
control functions corresponding to actuations of the
keys usually appear as actions in formation of the dis
play, e.g. space, new line, or carriage return.
Included in the bottom row of the keyboard are some
examples, such as the ASCII keys for “carriage return”
27, “new line" 34, and “interrupt" 28, as well as some
additional ?xed key functions such as a space key 26,
shift key 29, a CTL control key 25, and break key 35.
That same bottom row of keys also includes three
additional (non-ASCII) keys 30 through 32. These keys
represent certain additional ?xed functions often found
in computer-based services but which use different
character combinations in the different services. These
keys 30 through 32 in the illustrative embodiment are
sometimes called “hard" keys, to distinguish them from
the aforementioned soft keys l6 and 23, and because
their respective functions relate more to control of
hardware than software. Typical functions of the type
mentioned which are common to various computer
based services include delete last character CH, delete
line LN, and stop terminal output FRZ. The keys 30
through 32 provide, when actuated, function call char
acters for those three functions, respectively; and the
processor in station set It] automatically translates the
function call characters to the corresponding call code
used for the particular computer-based service then
interacting with the station set. The necessary data for
this translation is obtained by the processor during ini
tial handshake, i.e., set up operations, with the service
when it is ?rst connected.
FIG. 3 illustrates several general-purpose electronic
telephone station sets 36, 37, and 38 of the type herein
before described in connection with FIGS. 1 and 2. All
three of the station sets have two-wire voice lines 21
(subscriber loops) and data circuits 22 coupled to a
telephone switching of?ce 39 such as a class 5 telephone
of?ce switch or a private branch exchange switch. A
digital switching of?ce such as that described in the
aforementioned Alles or McDonald patent is one exam
ple of such an of?ce, and the disclosures of both such
patents are hereby incorporated herein by reference in
their entirety.
Within the of?ce 39, the data circuits are advanta
geously switched into communication with a host, such
as the host 40, as a peripheral unit. Sets such as the sets
36-38 are designed to be used with a host in the present
state of the art and stand-alone use is usually employed
only for testing, demonstrations, or emerging situations.
20
25
30
35
40
45
50
60
65
6
It is to be understood, however, that different propor
tions of the operational processing can be accomplished
within the set and remotely as the state of the art at any
time permits within the limit of having a small, conve
niently usuable set. Although the host 40 is shown at a
separate location from the of?ce 39 for convenience of
illustration, it can also be located within the of?ce or on
the subscriber's premises where the of?ce is a private
branch exchange (PBX) in such premises. In the latter
case the host functions and the PBX control functions
are advantageously all performed by a single processor.
In some applications where the sets 36-38 are relatively
remote from the of?ce 39 and coupled thereto by ordi
nary voice grade circuits, standard practice utilizes data
modems (not separately shown) at the set and the of?ce
for digital signals.
FIG. 4 comprises a simpli?ed diagram, partially in
schematic form and partially in block and line form, of
electric circuits of the station set of FIG. 1. The illus
trated circuit elements are primarily commercially
available elements, and where this is not the case addi
tional schematic information is shown in this ?gure or in
FIG. 5. In order to facilitate and understanding of the
operation of the invention, the diagram of FIG. 4 shows
primarily only data ?ow paths as realized in separate
space divided or time divided channels between equip
ments. The provision of timing and control arrange
ments to implement such separate channels for opera
tion of the illustrated equipment elements in accordance
with an illustrative process diagram, to be described, is
obvious to those skilled in the art.
The handset 17, the various types of keys of the key
pad 15, the display 13, and a loudspeaker 42, all previ
ously mentioned, are cooperatively coupled together by
a data processing facility including a processor 43. That
processor can be implemented in various ways depend
ing upon how much processing is to be done in the set
and how much in the host computer. In the illustrative
embodiment processor 43 controls basic telephone
functions (using the ASCII keyboard 20 for dialing).
For screen display of text information and for other
more elaborate functions, processor 43 cooperates with
a host computer such as a Digital Equipment Corpora
tion PDP 11/45 computer. In this environment proces
sor 43 advantageously includes a microprocessor such
as the INTEL Corporation 8748 microprocessor coop
eratively coupled with a program memory, such as the
INTEL 8755A programmable read only memory and
the Intel RAM and I/O Expander 8155 which also
provide supplemental input/output port facilities and
supplemental buffer memory for the microprocessor in
a manner now well known in the art. Such cooperative
arrangements are taught, for example in the INTEL
“MCS-48 TM Microcomputer User‘s Manual,“ 1978,
pages 3-9, 5-7 to 5-9, and 6-33 to 6-49. This arrange
ment provides suf?cient buffer storage for approxi
mately one-half of a fully written screen, which has
been found to be adequate for the general purpose sta
tion set application illustrated herein.
A data input port on processor 43 receives multibit
station set identi?cation number signals from ID
switches 56 included in the station set and settable by
the owner of the set to a predetermined number repre
sentation which is included in return status data mes
sages, to be described, for providing data processing
operation security and central of?ce billing information.
One output from processor 43 is a CLKR signal sup
plied to a clicker 74. That clicker is, for example, a relay