Tektronix 4956 User manual

Tektronix , Inc.
P.O.
Box
500
Beaverton ,
Oregon
97077
070-2210-00
TEKTRONIXⓇ
4956
GRAPHICS
TABLET
OPERATOR'S MANUAL
First Printing FEB 1977

AN
WARRANTY
This Tektronix product is warranted against defective materials
and workmanship , under normal use , for a period of one year
from date of initial shipment . Tektronix will repair or replace , at its
option ,
those products
determined
to be
defective
within
the
warranty
period and
returned ,
freight prepaid ,
to a
Tektronix
service center .
In
addition , in those
areas where
Tektronix
has service
centers
available for this product , on - site warranty repair is provided at no
charge
during the first
ninety ( 90
) days from
date of initial
shipment .
y
There is no implied warranty for fitness of purpose .
Copyright ©
1977 by
Tektronix , Inc.
Beaverton ,
Oregon .
Printed
in the United States of America . All rights reserved . Contents of
this publication may not be reproduced in any form without
permission of
Tektronix
,
Inc.
U.S.A. and foreign TEKTRONIX products are covered by U.S. and
foreign patents and / or patents pending .
TEKTRONIX is a registered trademark of Tektronix , Inc.
a

Section 1
Section 2
Section
3
4956
Graphics Tablet
CONTENTS
General Information
Some
Words
About
Terminology
Introduction to
the Graphics
Tablet
Graphics Tablet Components
Graphics Tablet Operation
Introduction
Generation of Coordinates
Digitizing
Modes
Time
and
Distance Filters
Origin
and
Coordinates
Transfer of Coordinates
Status
Byte
Back
Panel
Switches
Input
Procedure
Example Program
Tablet
Controller
Interrupt
Optimizing
Data
Transfer
Plot
50 :
Graphics
Tablet
Support
Software
Introduction
User
-
Definable Keys and
Graphic
Functions
Internal Data
Structure
Tape
Data
Structure
Operating
Notes
Initializing
Plot
50 :
Graphics
Tablet
Support
Software
Programs
for
the
Writing Pen
(
Menu
Items 1-5
)
Pen
Display Only
Pen
Display
and
Save
Pen Save Only
Pen
Display
and Store
Pen
Store
Only
Tape
Editing Programs
(
Menu Items
6 and 7 )
Data Tape Edit
Data
Tape
Merge
@
8
.
.
.
Page
1-1
1-1
1-2
2-1
2-1
2-1
2-2
2-2
2-5
2-5
2-7
2-8
2-9
2-9
2-10
3-1
3-1
3-2
3-4
3-6
3-7
3-8
3-8
3-10
3-14
3-17
3-19
3-22
3-22
3-30

ii
Section 4
Section 5
Section 6
Appendix
A
Appendix
B
Appendix C
Appendix D
Index
CONTENTS (
cont
)
Programs
for
the
Four
Button
Cursor
( Menu Items 8 through 12 )
Cursor
Display
Only
Cursor
Display and
Save
Cursor Save Only
Cursor
Display
and Store
Cursor
Store
Only
Tablet Maintenance
Biasing
the
Tablet
Checking
the
Tablet and
Tablet
Controller
Cleaning
the Tablet
Surface
Installation
Introduction
Installation
Steps
Setting
Coordinate
Units
AC
Power
Requirements
AC
Power Cord and
Grounding
Requirements
Line Voltage Selection
Fuses
Repacking
Information
Specifications
Internal
Switch
Settings
Plot 50 : Support Software Variables
Supplemental
Programs
Change
Information
Error
Messages
REV
. A ,
MAR
.
1978
.
.
.
.
.
Page
3-35
3-36
3-38
3-42
3-44
3-47
4-1
4-3
4-3
5-1
5-1
5-3
5-6
5-6
5-7
5-7
5-7
4956
Graphics
Tablet

Fig
.
No.
1-1
1-2
1-3
1-4
1-5
2-1
2-2
3-1
4-1
4-2
5-1
5-2
5-3
CONTENTS (
cont
)
4956
Graphics Tablet
ILLUSTRATIONS
Standard
4956
Graphics
Tablet
Graphics
Tablet
configuration in
4051
Graphic
System
Standard
Tablet
default
coordinate
plane
Tablet
Controller
Front
Panel
Tablet
Controller
Back
Panel
Different
Coordinate
Planes
Back
Panel
Switch
with
factory
settings
Four
Button
Cursor
Error
caused
by
uneven
Tablet
bias
Biasing
the
Tablet
Tablet
connection
GPIB
cable
connection
Internal
switch
locations
.
TABLES
Table
2-1A
Normal
Status
Byte
Values
2-1B
Special Four Button Cursor Status Byte Values
Back
Panel
Switch
Bank
2-2
3-1
Graphic Functions Represented in D values
3-2
5-1
5-2
6-1
Cursor Button and User - Definable Key Functions .
Range
of
Digitizing Units
4956
Operating
Voltages
4956 Operating Voltage Specification
REV . A , MAR . 1978
.
.
.
.
.
Page
Frontispiece
1-2
1-3
1-5
1-6
2-3
2-7
3-35
4-1
4-2
5-1
5-2
5-3
Page
2-6
2-6
2-7
3-4
3-36
5-4
5-6
6-1
iii

iv
TEKTRONIX
TEKTRONDE
KAN
VER
Fig
. 1-1 .
Standard 4956
Graphics Tablet
.
2210-01
4956
Graphics
Tablet
●

I
Section 1
GENERAL
INFORMATION
SOME
WORDS
ABOUT
TERMINOLOGY
The
TEKTRONIX 4956
Graphics
Tablet
is
designed
to
be used with a
TEKTRONIX 4050 - Series
Graphic System . The term Graphics Tablet is used in this manual to refer to the 4956 Graphics
Tablet
which includes the 20
" X 20 "
Tablet
as a
standard
component , and
Option
33
which
substitutes
a
36 " X 48 "
Tablet . The term
Graphic System is used to
reference
a
4050 - Series
Graphic System , which includes the 4051 Graphic System .
INTRODUCTION TO THE
GRAPHICS
TABLET
The Graphics Tablet inputs graphic data on command to the Graphic System through the
GPIB
interface . By using
BASIC
instructions
, the
Graphic
System
can
display
or store
the
graphic data
using
either
existing software or user -
designed
special
purpose
programs
. The
graphic material can be in many forms , such as handwriting , schematics , or freehand design .
With the feature of direct graphic input , the Graphics Tablet greatly enhances the graphic
capabilities of the
Graphic
System .
This section describes the three basic components of the Graphics Tablet : the Tablet , the
Writing Pen , and the Tablet Controller . Although the Tablet surfaces may vary in size , the
operating procedure is the same . The Writing Pen and Tablet are used just like pen and paper .
The function of the Tablet Controller is to convert the position of the Writing Pen on the Tablet
surface to the corresponding ASCII character coordinate pair . This process is called digitizing .
The coordinates and a status byte are sent to the Graphic System when an appropriate INPUT
instruction is executed . The operating procedure is explained in Section 2 of this manual .
4956
Graphics Tablet
Section 3 describes the Plot 50 : Graphics Tablet Support Software Tape which provides BASIC
programs that use Tablet coordinates and status information to display and / or store the
graphic data in memory or on magnetic tape . These programs are a convenient way to use the
Graphics Tablet . The programs make use of user - definable keys and five special programs are
included for use with the optional four - button Cursor . In addition , two programs edit data files
created
by the
software
programs .
1-1

GENERAL
INFORMATION
1-2
GRAPHICS
TABLET
COMPONENTS
The
configuration of
the
Graphics
Tablet
components in
the
Graphic
System is
shown
in
Fig .
1-2 .
The
following
paragraphs
describe
each
component
and
how
coordinates
are
digitized .
MANO MAN A
van me and they say
4051
77
TABLET
CONTROLLER
O
ma
WRITING
PEN
Fig
. 1-2 .
Graphics
Tablet
configuration in
4051
Graphic System
.
TABLET
2210-02
TABLET
The
Tablet and the
Writing Pen
are
used just like
pen and
paper
. The
Tablet has
a flat
surface on
which
paper
(
transparencies
,
etc. ) is
placed
.
The Writing
Pen
is
used
to
trace or
draw on
the
paper .
The
position of
the
Writing Pen
on the
Tablet
surface
is digitized
and
ASCII
character
coordinates are
produced
.
The
coordinates lie
on an X - Y
coordinate
plane
and
the
values are
relative to the
origin
. By
default , the
origin
is at the
lower
left
corner of the
Tablet
. X
coordinates
are
measured
horizontally
from the
origin and
Y
coordinates are
measured
vertically
as
shown in Fig
. 1-3 .
Identifiable points are .005 " apart .
4956
Graphics
Tablet

TEKTRONIX 4956
Y
Axis
Origin
( , 4000 )
4956 Graphics Tablet
( 0,0 )
Fig . 1-3 .
Standard
Tablet
default
coordinate
plane
.
GENERAL INFORMATION
@
(
4000 ,
4000 ) .
(
, 4000 )
To digitize coordinates , a grid of magnetized ( biased ) wires under the Tablet surface is used .
The
horizontal set of
wires is for the X
axis and
the
vertical set is for the Y
axis .
Pulses are
propagated along these wires and detected by a sensitive coil in the tip of the Writing Pen . The
time
between
transmission of a
pulse and its
detection
represents
a
coordinate
of
a point . For
each coordinate , two pulses are sequentially sent from opposite ends of the coordinates axis
wires , producing two values . The Tablet Controller then performs calculations on the two
values to produce highly accurate results .
X
Axis
2210-03
1-3

GENERAL INFORMATION
1-4
Only
a
certain
portion of the
Tablet
surface is used
as the
digitizing area
. This area
is not
marked on the
surface
since
it may move
when the Tablet
is biased
. (
Biasing
is
explained in
Section
4. )
However , the
minimum
size
of the
digitizing
area
is
standard
for
each of the
Tablet
sizes .
For example
,
the physical
size of
the standard
4956
Tablet
is 27.75
" X
27.75 "
while
the
digitizing
area
is
20 " X 20
" . The
digitizing
area may be
located by
moving
the
Writing Pen
on the
Tablet
surface near
the
metal
frame while watching
the
PROX
indicator on the
front panel of
the
Tablet Controller
. The
PROX
indicator
illuminates
when the
Writing
Pen is
in the
valid data
area
and
extinguishes
when
the
Pen leaves
the area .
WRITING
PEN
The
Writing
Pen is
used to
draw
on the
Tablet
surface
.
The tip of
the
Writing
Pen contains
a
sensitive
pick -
up
coil .
Whenever
the
tip
of
the Pen
is
within
5/32
inch of
the Tablet
surface ,
the
pick - up
coil detects
the
Tablet (
the
Pen is in
Proximity
) .
The
coil detects
the
change
in the
magnetic
field
caused
by
the pulse
on
the
Tablet
wires .
Coordinates
are
calculated
when
the
Pen detects the pulse .
Pressing
the tip of
the Writing
Pen against
the Tablet
surface
moves
the Pen's
filler
slightly
into
the
Pen .
This action
activates
a switch
,
located
within
the Writing
Pen
.
The Z
Axis
indicator
illuminates
when the
switch is
activated
.
This switch
can be
used
to
separate
coordinates
obtained
when
moving
the
Pen in
the
Proximity
area of
the Tablet
from
those
obtained
when
the
Pen is
actually
on
the Tablet
surface
as
explained in
Section
2
.
The
Writing
Pen's
inkless
filler
can be
replaced
by the
blue ballpoint
filler
so that
marks
can
be
seen .
If
accuracy is
desired
,
when
tracing
a
drawing ,
for
example ,
the
Writing
Pen
can
be
replaced by
an
optional
one -
button or
four -
button
Cursor
. In
the
Cursor ,
the switch
is
activated
by
pressing
the large
button on
top of
the cursor
.
TABLET
CONTROLLER
The
Tablet Controller
contains
the
power supply
and the
necessary
circuitry
to digitize
coordinates .
Upon
command of
the
Graphic
System ,
the
Tablet Controller
conveys
coordinate
and
status
information through
the
General
Purpose
Interface
Bus
(
GPIB ) .
Power is
applied
to
the
Graphic
Tablet
by
moving
the power
switch
on
the back
panel of
the Tablet
Controller
to
the
ON
position .
The front
panel
of
the
Tablet
Controller ,
shown
in
Fig .
1-4
,
contains
the
following
buttons
and
indicators .
NOTE
Before
applying
power to
the Graphics
Tablet ,
see the
installation
instructions
in
Section 5 .
4956
Graphics
Tablet

10
GRAPHICS
TABLET
REMOTE POINT STREAM
SWITCH
SWITCH
CLEAR INCRE
4956
Graphics
Tablet
ORIGIN
Tablet Controller Front Panel Buttons
REMOTE - Reserved for custom modification .
LOW
STREAM
Fig . 1-4 . Tablet controller front panel .
TEKTRONIX
4956
HIGH
Z AXIS
(
@
GENERAL
INFORMATION
PROX
POWER
POINT - A single point is digitized each time the Writing Pen is pressed on the surface of the
Tablet (
switch
activated
) .
2210-04
STREAM SWITCH - Points are digitized as long as the Writing Pen remains on the Tablet
surface (
switch
activated ) .
STREAM SWITCH - Points are continuously digitized while the Writing Pen is in the Proximity
area or on the Tablet surface .
CLEAR - The microprocessor is reset and the origin is set at the lower left corner of the Tablet
surface . The GPIB interface is also cleared .
INCRE - To be accepted , the coordinates of a point must be at least 2 counts ( 0.1 inch ) away
from the last accepted point on the X or Y axis .
ORIGIN ― When pressed , the origin is set at the next point digitized .
STREAM ( slide ) -The rate of digitization is adjusted on a time elapsed basis . Points are
digitized approximately 3 per second at the Low setting and 30 per second at the High setting .
1-5

GENERAL INFORMATION
1-6
Tablet Controller Front Panel Indicators
Z AXIS - Illuminates when the Pen ( or Cursor ) switch is activated .
PROX - Illuminates when the Pen ( or Cursor ) is in Proximity ( within 5/32 inch of the surface of
the
Tablet ) .
POWER -
Illuminates
when power is
applied to the
Graphics
Tablet . The
POWER
switch is
located on
the back
panel
of the
Tablet
Controller as
shown in
Fig . 1-5 .
POWER ON
Cuenca
O
оо
J3
34 AMP 5B
O
J4
J5
J1
(
8
)
J6
Fig
.
1-5 .
Tablet
Controller
Back
Panel .
BPS
J2
2210-05
4956
Graphics
Tablet

STANDARD
ACCESSORIES
The following standard accessories are included with the Graphics Tablet at no extra charge .
Operator's
Manual
GPIB cable
PLOT 50 : Graphics Tablet Support Software Tape
Biasing Magnet
Fastener Pile
Fastener Hook
4956
Graphics
Tablet
OPTIONAL ACCESSORIES
The following optional accessories are available for the Graphics Tablet at additional cost . To
order any accessory contact the nearest Tektronix , Inc. Field Office .
Cursor (
replaces
Writing
Pen )
One
button
Four
button
Pen
Filler
GENERAL INFORMATION
Dry
Blue
Service
Manual
(
@
1-7

Section 2
GRAPHICS TABLET OPERATION
INTRODUCTION
Two basic functions are performed by the Graphics Tablet : generation of coordinates and
transfer of coordinates to the Graphic System . This section explains how these functions are
controlled by setting Tablet Controller external buttons and by executing BASIC instructions
from
the
Graphic
System .
GENERATION OF COORDINATES
Digitization is controlled by the buttons on the front panel of the Tablet Controller . These
buttons select one of three digitizing modes : point , stream switch , and stream switch . Other
front panel buttons set time and distance filters and re - locate the origin .
DIGITIZING MODES
The Graphics Tablet can digitize in any of three modes : point , stream switch , or stream switch .
The mode selected determines how the Proximity area and the Pen switch are used . The
following paragraphs describe each mode .
POINT Mode
When the POINT button on the Tablet Controller front panel is pressed , the Tablet Controller
digitizes one point and generates status information ( see " Status Byte " in this section ) each
time the Writing Pen is pressed on the Tablet surface . The pen must be lifted and then pressed
to the surface to generate another point . This mode is useful when only a particular point is
required , for example , when specifying the endpoints of a straight line that is drawn by a BASIC
DRAW
instruction
.
STREAM SWITCH Mode
By pressing the STREAM SWITCH button , points and status are generated continuously while
the Writing Pen is on the Tablet surface and the Pen switch is activated . This mode is useful
when tracing or drawing freehand .
STREAM SWITCH Mode
When STREAM SWITCH mode is selected , points and status are generated continuously while
the Writing Pen is in Proximity ( PROX indicator illuminates ) or while the Pen switch is activated
( Z AXIS indicator illuminates ) by pressing the Pen on the Tablet surface . This mode may be
useful when
delicate paper is used
or
precise
drawing
is
required
.
4956 Graphics Tablet
@
2-1

GRAPHICS TABLET OPERATION
2-2
TIME
AND
DISTANCE
FILTERS
Filters
are used to
reduce
the amount
of
data
stored
to
manageable
proportions
and to
reduce
the
effect
of pen
tremors
that
convey
undesired
data .
STREAM Slide ( Time Filter )
A
time
filter
is
implemented
by
moving
the
STREAM
slide .
The
time
filter
adjusts
the
rate
of
digitization
on a
time
elapsed
basis
.
The
rate
of
digitization
is
increased
as
the
STREAM slide
is
moved to the right .
A
slow
rate
of
digitization
may
be
useful when
storage
capacity
is a
consideration
,
and a
high
rate
of
digitization
may
be
useful
when
making
curves
or
drawing
quickly
.
The
approximate
range
of
the
total
time
for
generation
and
transfer
of
data
is 3
points
/
second (
LOW
)
to
30
points /
second
( HIGH
)
.
The
actual
time
depends
largely
on
the
software
(
see "
Optimizing
Data
Transfer " in
this
section ) .
INCRE
Button (
Distance
Filter )
When
the
INCRE
button is
pressed ,
a
distance
filter
is
implemented
. The
distance
filter
adjusts
the
rate
of
digitization
on
a
distance
basis
.
The
Writing
Pen
must
be
moved
at
least
.01 inch
(
two
counts )
in
the X
or Y
direction
before
the
next
point
is
digitized
and
accepted
.
The
distance
filter
checks
points at
the
digitization
rate
set
by
the
time
filter
.
Because
fewer
points
are
generated ,
this
feature
is
useful
when
storage
capacity
is a
consideration .
Also
,
when
drawing
slowly ,
the
distance
requirement
reduces
the
effect
of
pen
tremors .
ORIGIN
AND
COORDINATES
The
coordinate
system
used
for
digitization
can
be a
one- ,
two-
,
or four
-
quandrant
coordinate
plane
,
depending
on
the
location
of
the
origin
. When
power is
applied
,
the
default
origin
is at
the
lower
left
corner
of
the Tablet
surface ,
which
results
in a
one -
quadrant
coordinate
plane
with
positive
coordinate
values .
The
origin
can
be
located at
any
valid
data
location
.
By
moving
the
origin
, the
X
and Y
axes
are
moved
and
the
Tablet
surface
is
divided
into
one ,
two , or
four
areas (
quadrants
) as
shown in
Fig .
2-1 .
Coordinates
are
measured
from
the
origin
.
Positive
coordinates
are
generated
upwards
and
to
the
right
of the
origin .
Negative
coordinates
are
generated
downwards
and
to
the left of the origin .
4956
Graphics
Tablet

4956
Graphics Tablet
TEKTRONIX 495
Default
Origin
TEKTRONIX 4956
ONE
QUADRANT
X axis
Y
axis
Quadrant 1
X
negative
Y
positive
Quadrant
1
X positive
Y positive
TWO QUADRANT
Y
axis
1
Quadrant 2
X
positive
Y
positive
Origin
X axis
TEKTRONIX
4956
@
Origin
Y
axis
TEKTRONIX 4956
X axis
TWO QUADRANT
Fig . 2-1 . Different coordinate planes .
X
positive
Y
positive
Quadrant 1
X
positive
Y negative
Quadrant
2
X
negative
Y
positive
GRAPHICS
TABLET
OPERATION
FOUR QUADRANT
Quadrant
3
X
negative
Y
negative
1
|
Y
axis
Quadrant 1
X
positive
Y
positive
Quadrant 4
X
positive
Y
negative
X axis
Origin
2210-06
2-3

GRAPHICS TABLET OPERATION
2-4
Tablet
Controller
internal
switches
control the
measuring
unit of
the digitized
coordinates .
Coordinates
can
be
generated
in
count ,
inch , or
millimeter
units .
The default
unit is
counts .
Because
these
switches are
internal and
not
designed to
be changed
by an
operator ,
information
on
internal
switch
settings
is
contained in
Section
5 , "
Installation .
"
Conversion
from
counts
to
millimeters or
inches
can also be
accomplished
by
a
BASIC
instruction
that
multiplies
each
coordinate
by
the
appropriate
conversion
factor as
follows
:
1 count
=
.005
" =
.127
mm (
approximately )
.
See
the
reference
manual
included
with
the
Graphic System
for
details
on
BASIC
instructions
.
RELOCATING
THE ORIGIN
The
location of
the
origin
determines the
coordinate
plane .
The origin is
relocated
by
pressing
the
ORIGIN
button
and
generating
a
point .
The
process
differs
slightly
depending on
the mode
of digitization .
In
POINT
mode
,
press
the
ORIGIN button
and
hold it
in .
Move
the
Writing
Pen
to
the
desired
origin
and
press
the
Pen
on
the Tablet
surface
while
holding
the
ORIGIN
button in
.
Release the
ORIGIN
button and
the
origin is set .
In
STREAM
SWITCH mode
,
follow
the
procedure
for POINT
mode
or
use
the method
described
in
the
following
paragraph
for
STREAM
SWITCH
mode
.
In
STREAM
SWITCH
mode ,
first
position
the
Writing
Pen
on
the
Tablet
surface at
the
desired
origin
.
Press
the
ORIGIN
button
while
holding
the
Writing
Pen
on
the Tablet
surface .
Release
the
ORIGIN
button
and the
origin is set
.
CLEAR
By
pressing
the
CLEAR button
,
the
default origin
(
lower
left
corner
) is
set
.
The
CLEAR
button
initializes all
Tablet
Controller
circuitry to
default
parameters
and clears
the GPIB
interface .
NOTE
Do
not
press
CLEAR
while
a
program
is
inputting
data
from
the Tablet
Controller
.
Halt
the
program
first by
pressing
the
Graphic
System
keyboard
BREAK
key
twice .
If
the
CLEAR
button is
pressed
during a
data
transfer ,
the
Graphic
System
must be
turned OFF before it will operate again .
4956
Graphics
Tablet

TRANSFER
OF
COORDINATES
The
General
Purpose
Interface
Bus ( GPIB
) is
used to
transfer
coordinates
from
the Tablet
Controller
to the
Graphic
System . To
communicate
, the
Graphic
System is
assigned the
role of
"
listener "
and the
Graphics
Tablet is the
" talker
. " By
executing an
INPUT
instruction ,
specifying
the
address
of the
Graphics
Tablet , the
Graphic
System
receives
X
and Y
coordinates
and
status information
. A set of
switches on
the back
panel
of the
Tablet
Controller
control the
address
and
SRQ
mode (
SRQ
is
explained
in the
reference
manuals
included with
the
Graphic
System ) . The
following
paragraphs
describe the
transfer
procedure
.
GRAPHICS
TABLET
OPERATION
STATUS BYTE
A status byte is generated with each coordinate pair to indicate the position of the Writing Pen
( or Cursor ) and the button pressed on the optional four - button Cursor . The status byte is a
single ASCII character . The normal status byte values and the associated meanings are shown
in Table 2-1A .
A status byte of 1 can be obtained in any digitizing mode . A status byte of Ø is obtained when
STREAM SWITCH mode is selected and the Pen is in Proximity . Status values 2 , 4 , and 8 are
obtained when the four - button Cursor is used . These status byte values can be used to
represent graphic functions such as draw , move , and halt . A BASIC program can branch to a
particular subroutine to perform a graphic function depending on the value of a status byte .
NOTE
4956 Graphics Tablet
Other status byte values can be obtained by simultaneously pressing more than one
button on the four - button Cursor . These status byte values are not normally used
because of the difficulty of simultaneously pressing combinations of buttons . The
possible status
byte values
that result from
combinations
of
buttons on the four
button Cursor are listed in Table 2-1B .
2-5

GRAPHICS TABLET OPERATION
2-6
ASCII
Character
Status
Byte
1
2
4
8
ASCII
Character
Status
Byte
3
5
6
7
9
:
;
V
IIA
C.
>
?
Table 2-1A
NORMAL
STATUS
BYTE
VALUES
Meaning
The
Pen ( or
Cursor
) is in
Proximity .
The
Pen (
or
Cursor
) switch
is
activated
.
Button 3
on the
optional four
-
button Cursor
is
pressed .
Button
2 on the
optional
four -
button
Cursor is
pressed
.
Button 1
on the
optional
four
-
button
Cursor is
pressed
.
Table 2-1B
SPECIAL
FOUR -
BUTTON
CURSOR
STATUS
BYTE
VALUES
Meaning
Button 3 and
the
Cursor switch
button on
the four -
button
Cursor are
pressed .
Button 2 and
the
Cursor
switch button on the
four -
button Cursor are
pressed .
Buttons 2
and 3 on
the four
- button
Cursor are
pressed
.
Buttons 2
and 3 and
the
Cursor
switch
button on the four
-
button Cursor
are
pressed .
Button 1
and the
Cursor
switch
button on the
four
-
button
Cursor are
pressed
.
Buttons 1 and
3 on the four
- button
Cursor are
pressed .
Buttons 1
and 3 and
the
Cursor
switch
button on the four
-
button Cursor
are
pressed .
Buttons 1 and 2 on the four - button Cursor are pressed .
Buttons 1
and 2 and
the
Cursor switch
button on
the four
- button
Cursor are
pressed .
Buttons 1 , 2
, and 3 on
the four -
button
Cursor are
pressed .
All buttons on the four - button Cursor are pressed .
8
)
4956
Graphics
Tablet