InkWell Systems The LightPen User manual

PLEASE READ BEFORE USING THE LIGHT PEN
This package contains an INKWEll SYSTEMS' light Pen, a copy of a computer
program recorded
on one or more (sides) of a magnetic olskette(s), and supporting
documentation.
This material embodies proprietary rights protected under the U.S. Copyright
laws and the
trade secret laws of most states.
Your purchase of this package Is sUbject to the following terms and Conditions:
Purchaser acquires
full title and possession of the light pen and dlskette(s).
and a limited. non-exclusive license to load the copy
of the computer program Into a
pgrsonal micro processor and to make
one archival or Working Copy of It on a sparg
dlskette(s).
Purchaser
Is not authorized to make any other copy of the computer program.
to
transfer possession of any copy of the program to another person. to load a copy of
the program on any multi-User system or use It In rendering any kind of
software-related services which might result in copying by other persons, to modify
and/or adapt the computer program In any way Including translating. reverse
engineering. decomplllng or disassembling the computer program.
Violation of any of the above terms and conditions may subject the purchaser
or any other person to civil liability and actual or statutory damages under Title 17 and
28 of the U.S. Code. WIllful violation of the Copyright law Is a felony punishable by heavy
flngs and/or Imprlsonmcmt. LIMITED
WARRaNTY NOTICE
INKtJ[LL SYSTEMS warrants the dlskette(s) as free of defect In material and
workmanship. and the recorded copy
of the computer program as an accurate copy of
the original for a period of 90 days from the date of purchase.
INKWfll SYSTEMS warrants the light Pen Model 170-C to be free of defect In
matgrlal and workmanShip for a period of ninety (90) days and warrants thg light Pen
Model 181-C to be free of defect In material and workmanship for a period of ninety (90)
days.
EXCLUSIVE REMEDIES
Items found defective and returned to INKWELL SYSTEMS during their warranty
period will be repaired or replaced free of charge; providing that the applicable WllRRNiTY
REGISTRATION CARD Is on file at INKWELL SYSTEMS.
"OlICE: I..IAIlRAltlV RE6181RAI10" CARD MU81
BE 0" fiLE AT IHKWELL SYSTEMS fOR
WARRAitlY .COVERA6E. TO RECEIVE TECHHICAI..
8UPPORT AltO TO RECEIVE PRODUCT UPDATE
I"FORHATIOH IF APPLlCMLE.
EXCLUSION
The computer program Is made available to you "NJ IS". NO WllRRNiTY EITHER
EXPRESSED OR IMPLIED IS MADE ~ TO ITS APPLICATION OR FITNESS FOR NiY PURPOSE. IN NO
EVENT WILL INKWELL SYSTEMS. ITS LICENSORS OR ~SOCIATES BE HELD LIABLE FOR NiY TYPE Of
DN1MES RESULTING FROM NiY DEfECT IN THE COMPUTER PROGIW1 OR fROM NiY USE OR ATTEMPT
TO USE IT.
This above limited warranty Is In lieu of any other expressed or Implied
warranty. It gives the purchaser specific legal rights. There may be other rights which
vary from state to state .. Some states prohibit limitations on the extent and duration of
Implied warranties.
COPYRIGHT AND TRaDEMARK INFORMATION
n.lddr...., F1txlfont, Pen ...... , or .. tos Intlgr.tGr 2II1II Tht l""t P .... are Tramrb of
I«'t'Rl. SYST£HS. Cornrnodon 64, 64C, 128 SX64, and Amtga are npttnd b'adtrnIrb of Commodon
Bustntu Maohtlts, Ino.
"THE LIGHT PEN" COPYRIGHT 1987 by INKWfLL SYSTEMS. ALL RIGHTS RESERVED.
1f!K'W(5f &.-L- s;V!(;r7FY;"5'
fJfJ6 Iqq 7 1 q
-T1"I1 ,aE/.J (ITe- 6F4
C
ff) c,q. I :3.3

Tit£. e.i.Qht qJEn
TABLE OF CONTENTS
The Light Pen Contents
And Warranty"",,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 2
Welcome To The Light Pen" ... """. 4
Do's And Don'ts""."""""""""""""""", 5
Hardware Requirements .. "."".""", 6
To Use The Light Pen With
Other Personal Computers."" 7
What Is A Light Pen?""""".".""""" 8
How A TV/Monitor Works" .. ".""" 8
About Phosphor""""",,,,,,,.,,,,,,,,,,,,,,,,,., 10
How The Light Pen Works"""""" 11
Hardware Background For
Programming The Light Pen"",12
Programming Tips""""""""".""""",,,,,13
The Light Pen Demonstration Disk
Getting Started"""" .... """"" .. ,,""'''',, .. ,15
Loading The Light Pen
Demonstration Disk"""""""""""" 16
Where Am 17 .. III •• Ilt' ... , •••• I ... " .... IIIIII ......... 17
The Light Pen Piano .... " .. "" .. ,,"""""" 18
The Light Pen Synthesizer"""""", 18
Follow Me!, ...... "." ....... " .... ,.,I"."I,I, •••• ,.••,I ••• l8
MA17B4

T Iu:.. e.ight qJut
CONTENTS AND WARRANTY.
Your light Pen peckege contelns the following ttems:
• LIGHT PEN APPLICATION DEMONSTRATION DISK
(COMMODORE 61, 120, S)(6-1 FORMAT)
• I ?OC OR 10iC HIGH RESOLUTION LIGHT PEN
• OPERATIONS MANUAL
• WARRANTY CARD
If this peckege Is not complete, Immedletely return tt to the place of
purchase.
The light Pen Appllcatton Demonstratton Disk contains the following
programs to show possible use of the light pen In programs that you create:
FOLLOW HE!, LIGHT PEN PIANO. SYNTHESIZER, and WHERE AM 11
To get started using your light Pen, we recommend that you read thelDllrl
1IlmllI.Ql. All programs on the Demonstration Disk are acces.sed by typing:
LOAD ···.8 <RETURN>
RUN <RETURN>.
PLEASE NOTE: WARRANTY REGISTRATION
CARD MUST BE ON FILE AT INKWELL
SYSTEMS FOR WARRANTY COVERAGE
AHD TO RECEIVE TECHHICAL
ASSISTAHCE. IF REQUIRED.
INKWELL SYSTEMS OFFERS YOU A 15 DAY, MONEY BACK GUARANTEE. IF YOU ARE
NOT PLEASEO WITH THIS PRODUCT, RETURN IT TO YOUR PLACE OF PURCHASE. IF
YOU PURCHASED THIS PRODUCT DIRECTLY FROM INKWELL SYSTEMS, PLEASE
CONTACT THE FACTORY FOR AN RMA· (RETURN MERCHANDISE AUTHORIZATION).
YOUR MONEY WILL BE REFUNDED. NO REFUNDS WILL BE GIVEN FOR MERCHANDISE
OVER 15 DAYS OLD. MERCHANDISE RETURNED TO THE FACTORY WITHOUT AN
RMA • IS SUBJECT TO ADDITIONAL SHIPPING/HANDLING CHARGES.

ThL e.4Aht. rpm
CONTENTS AND WARRANTY
If you do eKpenence any problems' with your INKWEll SYSTEMS light Pen or
Demonstration Disk, please follow these Instrucltons:
1) Disk: 90 Dey Worronty
DURING WARRANTY PERIOD: contact factory for RMA #I (Return Merchandise
Authonzatlon) belore returning the diskette to Inkwell Systems. Than
return damaged disk. You will receive a replacement at no charge If the
onglnal dl~kette Is found to be damaged.
AFTER WARRANTY EXPIRES: Contact factory for RMA #I (Return Merchandise
AuthonzaUon) belore returning tha diskette to Inkwell Systems. Than
return damaged disk and $15.00 ($15.00 US In Canada and Mexico, $20.00 for
other foreIgn countnes). You will be sent a replacement. ThIs charge
Includes replacement and shIpping/handling charges.
" '
2) THE LIGHT PEN MODEL 170-C; 90 Day, Warranty
DURING WARRANTY PERIOD: Contact Factory for RMA #I (Return Merchandise
AuthonzaUon) lIelor. returning the pen. Upon receipt, any pen found
defective In matenals or workmanship will be repaired or replaced free of
chorge.
AFTER WARRANTY EXPIRES: Contact factory for RMA #I (Return Merchandise
Authonzolton) belor.returning The LIght Pen to Inkwell Systems. Than
return dftmftgod light (len ftnd $55.00 ($55.00 US In Cftnftdft ftnd MeKlco, $65.00
other foreign countries). Vour.pen will be repaired or replaced and be returned
to you ,with a new ninety day warranty. This chargl' Includes repair or
replacement and shipping and handling charges.
3) THE LIGHT PEN MODEL I Q4-C: 90 Day Worronty
DURING WARRANTY PERIOD: Contact Factory for RMA #I (Return Merchandise
Authonzatlon) before returning the pen. Upon receipt. any pen found defecltve
In matenols or workmanship will be replaced and returned to you free of
charge.
AFTER WARRANTY EXPIRES: Due to the sealed construction on thIs model
of light pen. we do not repair them. Replacements can be purchased directly
through your local Inkwell Systems Dealer.

WELCOME TO TAL f4Ahi f/JUl
Congratulations on your purchase of The Light Penl Inkwell Systems Is very
pleased that you have chosen this data entry device for your computer system.
The following pages contain a technical discussion regarding light pens: how
they work, how your system works with relationship to The Light Pen and
what Information will be needed to create a program for It.
Also Included In this package Is The Ught Pen Demonstration Disk which will
run on a Commodore 64, 64C, SX64 or 126 computer and shows the many
things a light pen can accomplish when programmed correctly. These
programs range from menu selections through panel controls. Also Included
on the disk Is a program to enable you to determine the exact location of the
light pen on the screen for use In your own programs.
As stated above, the following pages are technical In nature and are written
for
those Individuals who wish to create a program for The Light Pen. Inkwell
Systems wishes to advise you that unless you plan to use The Light Pen wtth
programs compatible wtth light pens already avatlable on the market you will
need to create your own programs for use with The Light Pen. The
Demonstration disk Included Is Just for demonstration purposes and 'by no
means Is ·useful· software.
QUESTIONS? Check wtth your nearest Flexldraw Deiller, or contllct:
Customer Service
INKWELL SYSTEHS
P. O. Box 1997
Imperial Beach, CA 91933
[phone]

DO'S AND DON'TS
Do: Store The Light Pen In a cool dry place.
Do: Occllslonlllly wipe your screen wtlh II dllmp cloth or your hllnd
to reduce dust lind stftUC electrlctly which mfty affact tha
operftUon of The Ught Pen.
I
Do: Adjust tha Color. Brtghtness. and Contrast controls of your
television or montlor for the best possible display.
Do: Occasionally use atwisted plect of tissue paper to remove
.~
IIny dust thllt hilS IIccumulllted Inside the Up of the light pen.
Do: ContDct your Inkwell Systems DeDler If you hDve Dny
questions.
Don It: Drop or bang the light pon on a hard SUrfacO.
Don It: Store your light pen or disks In the sun or Dny place where
there Is excessive heat.
D on It: Tak.t The light Pen apart. If you suspect e problem contect
your 10CDI dealer or Inkwell Systems Customer Service for
Dsslstlince.
o on It: Use The light Pen Model '70-C on D CRT screen thftt Is not
smooth. Usl! of the pen's nose Up swtlch on a textured screen
could damage the screen surface and/or The light Pen.
Don It: He tum Men:hllndlse to Inkwell Systems w'thout
niSI obtelnlng lin HMH# liS destrtbed In the
Tlilt lIll1t '11. CII.ttJ.t6 •• 11 llI.rr •• ',
settlon of this mllnulIl.

HARDWARE REQUIREMENTS
The Light Pen is joystick Port I compatible with Commodore 64, 64C, SX64,
and 128 computers. To program for The Light Pen you will need:
• A COMPUTER WITH SUITABLE LIGHT PEN INTERFACE
• COMPATIBLE DISK DRIVE
• TV OR MONITOR SUIT ABLE FOR USE WITH THE LIGHT PEN
(See the About Phosphorsection in this manual)
•
COMPATIBLE DISKETTES
To run The Light Pen Demonstration Disk you will need:
• COMMODORE 64, 64C, SX 64, or 128 MICROCOMPUTER
• COMPATIBLE DISK DRIVE
• TV OR MONITOR SUIT ABLE FOR USE WITH THE LIGHT PEN
HOW TO USE Th£. e.ight qJE.fl
WITH COMMODORE COMPUTERS
• 170-C Light Pen: Insert The Light Pen in Control Port I which is
located on the right side of the Commodore 64, 64C and 128 computers and in
the rear of the SX64 portable. Press the tip of The Light Pen to the CRT to
perform the functions the software dictates. (HINT .. .For a ·second switch"
you can program the <Control Key> or the <Back Arrow> key.)
• 184-C light Pen: Install The Light Pen as above. While it is not
necessary for the tip of this pen to be placed directly on the screen to
position objects or the make selections, It is recommended that you use the
pen no more than six Inches away from the screen for optimum operation. To
activate the touch switches, simply lay your finger gently on the switch. It
activates using the moisture In your skin as a conductor. Each switch can be
programmed to perform different functions ... Le. the right and left button on a
mouse. (HINT: If you have extremely dry skin, we recommend using hand
lotion before using The Light Pen for best results. We have also noticed that
you may get a jumpy cursor if you operate the 184-C close to a megawatt
radio stat Ion).

TO USE Til£. e.ight qJE.fl WITH
OTHER PERSONAL COMPUTERS
The light Pen may be adapted for use on other personal computers which have
alight Pen Port. To do so, you must read through their respective manuals to
determine where lind how to connect The light Pen to the computer.
The light Pen comes packaged with a 9 position wD
w
Subminiature connector
wired as follows:
MODEL 184-C
Pin I: Not Connected
2: Not Connected
J: Black Switch 2
4: Not Connected
5: Yellow Switch I
6: Green Video
7: Red +5V
8: Shield Ground
9: Not Connected
MODEL 170-C
Pin I: Not Connected
2: Not Connected
J: Black SWitch
4: Not Connected
5: Not Connected
6: Green Video
7: Red +5V
8: Yellow Ground
9: Not Connected
;:~: - ....... 'S---<~
0 00 00
i/r---r-)- ~:~ ~
"0" Submlnl8ture Connector
Other computers will require the wD
w
Subminiature connector to be removed
and a different style connector to be purchased and Installed. It Is
recommended that only those with technical background attempt
modifications themselves. lrikwell Systems recommends that any
modifications be made by areliable computer dealer/repair station.
Modifications to The Light Pen which result In a pen malfunction will void the
Warranty and It Is urged that the connector modifications be carefully
Inspected to prevent serious damage to the computer and/or The light Pen
when Installed.
Inkwell
Systems Is not responsible for any damage to a computer system by a
mud" led lIyhl pen,

WHAT IS A LIGHT PEN?
A l1ght pen Is a hand-held electro-opttcal polnttng device which, when
touched to or aimed closely at a connected monitor or TV screen, wl11 aHow
the computer to determine where on that screen the pen Is aimed.
The software and l1ght pen driver may process this location Information In
various ways, but the job of the pen Itself Is simply to make a ttme
measuremsnt which wl11 be translated Into X and V coordInates representative
of a posltton on the CRT (cathode ray tube, I.e., TV or monItor).
There are two parts to a l1ght pen system: the hardware (the lIght pen and
computer system to which tt Is attached) and the software (which can range
from Simple to complex).
The hardware determines the resolutton and accuracy which Is attainable
with
the system. The software determines the usefulness of the l1ght pen and
the sophlsttcation level and speed at which tt performs.
The l1ght pen Is areal-time Interacttve deylce and tts performance should be
on par with the operator. Programs whIch are written primarily In a high
level language, such as Interpreted BASIC, are usuaHy so slow that the
usefulness of the light pen system Is greatly dIminIshed. It Is suggested that
machine code be used for you to get the most out of your light pen system.

HOW A TV IMONITOR WORKS
To understand how aught pen works, you must ftrst understand how the video
output Is displayed on yourTY or monitor (CRT).
In your computer system there Is a special chip (sometimes called a video
chip) which handles everything associated with video output Including colors,
characters, sprites, graphics, screen organization and the light pen.
To l11umlnate your CRT, the electron beam located Inside the CRT wl11 start In
the upper left comer of the screen alld sweep (paint) from left to right unlt1 a
horizontal sync pulse (generated bya counter chip) Is encountered. At this
time the electron beam gun Is turned off and quickly returns to the left side
Just below the previous starting point. It wl11 continue to paint In this
fashion for a given number of times until a vertical sync pulse (generated by
another counter chip) Is encountered, at which time It returns to the top-
most, left-most position to begin the process all over again.
The left to right scan Is caned a line. The series of lines from top to bottom
Is called a frame. Each line consists of a series of phosphor dots and these
dots are called pixels.
The number of dots per line Is determined by another counter chip called a dot
counter, while the size of each dot Is determined by the size and type of CRT
and by the frequency of the clock circuit.
The number of dots In each Itne and the number of lines In each frame are
referred to as resolution; I.e. 320 X 200 resolution simply says there are 320
dots per line and 200 lines per frame. The larger the numbers, the higher the
resolution. The higher the resolution, the smaller the dots are In size and the
closer the Itnes appear on the scraen.
All of the previous Infonnatlon has described physically what Is happening to
the CRT. What this means simply Is that the electron beam Is actually
drawing a picture on the CRT, Itne by Une, by turning on and off pixels. This
entire picture (frame) Is being painted on the CRT 60 times a second.
Sometimes this painting action Is called -refreshing- the screen.

ABOUT PHOSPHOR
Perhaps the most critical element In the performance of a Hght pen Is the
type of phosphor
used In the CRT. For optimum efficiency, it Is recommended
that a fast persIstence phosphor be used with The Ught Pen.
SInce The Ught Pen uses Its photo detector to determIne when the electron
beam strikes a pixel within Its fteld of ylew, It Is Important that there be
adequate contrast between an "on" and "off" pixel. The greater the light the
pIxel glyes
off, and the faster It goes from on to off, the more accurate The
Light Pen wt11 perform.
If the phosphor dots glow and become black yery QuicklY, the phosphor Is said
to
haye a short persistence. Host TV's and monitors haYe this rating.
If the phosphor dots tum on and slowly tum off, It is said that the CRT has a
long persistence
phosphor. Another common term for this Is an "easy on the
eye" CRT or one that reduces operator filtigue.
On a long persistence phosphor CRT It is sometimes easy to see the
difference.
The Images seem to streak or "ghost" on the screen when you
moye them; l.e. the cursor on a word processing program wt111eaye a trail as
you move It from left to right.
it Is Important to know the CRT resolution and to determine If it has a slow
or fast persIstence phosphor when making a decisIon as to what type of light
pen to use.
On color TV's and monitors, It Is recommended that the color "clear red" not
be used In conjunction with pen operation. The red phosphor emits such a low
leyel
of light oyer along period of time, that the photo detector may not see
the on-off contrast and the pen may appear not to function properly. This can
be oyercome by Introducing another color, preferably blue with the red, which
wl11 glye the light pen adequate contrast to "on" and "off" pixels.
$10$

HOW TIlL fight. tpUl WORKS
The light Pen contains a lens and aphoto detector located In Its tip. When the
electron
beam strikes the phosphor within the pen's field of view, the light
emitted by the phosphor Is focused through the lens and onto the photo
detector. This acllon
causes an Increase In signal current and Is transmitted
to the computer.
The light Pen contains aproperly selected lens and photo detector as well as
an aperture to enable It to detect the flash of the pllssage of the bellm while
Ignoring the residual glow
of the phosphor. When the flash Is detected, the
photo detector sends a signal to the computer lind the position of the beam Is
kept track of by the horizontal and vertltal counters which relay this
Information to a register.
(See the HARDWARE DAC~oROlIND FOR
PR06RAlflflN6A Ll6HT PEN section In this mllnulIJ).
This cycle Is repeated for every frllme produced by the electron beam. To
enable the position of the beam to be accurately located, your light Pen
contains a very high speed photo detector. The flash of a single dot of
phosphor on the screen lasts only several micro seconds (millionths of II
second). Oy noting when II sClln goes by lind measuring the InterYlIl between
scan lines or entire screen refreshes, you can get an accurllte position of the
photo detector on the CRT. The pen then enables you, through software, to
generate Xlind Vvectors corresponding
to apoint on the screen which you mlly
then use to drllw pictures, make II choice from II menu of allernlltlves, or
IInswer questions put to
you by II progrllm.
As opposed to Input viII keybollrd, Joystick, mouse or tablet, alIght pen clln be
II dramatically friendly peripheral. Imagine needing merely to point the pen at
the screen In order
to mllke a choice, or to draw a picture on the CRT liS
simply liS with a crllyon on paper. There are mllny diverse possibilities a light
pen affords. Vou are only limited by your Imllglnatlon.
~II~

HARDWARE BACKGROUND FOR
PROGRAMMING Tit£. e.4A1J:. qJUl
In the long run, a basic understanding of the relation of the hardware
functions to the yldeo and light pen portion of the computer wt11 anow for
better
programming.
In yery simple terms, the yldeo generatton circuit mau be thought of as two
counters, horizontal and Yertlcal, driYen bU an osct11ator caned the dot
clock. The counters In tum are used i.~1 access the screen memory which
holds the Image to be dlsp1aued.
LIGHT PEN VIDEO
LIGHT PEN
REGISTER
DOT HORIZONTAL
CLOCK
COUNTER
VIDEO VIDEO
HORIZONTAL
MEMORY OUT
SYNC
VERTICAL
COUNTER
S
VERTICAL
CO
SYNC
The screen random access memory (RAM), which Is addressed bU the
horizontal and yertlcal counters, determines whether each dot (pixel) wl1l be
·on· or ·oW, depending on the state of each corresponding bit In the screen
RAM.
The output of the photo detector Is amplified and that signal Is compared to a
threshold yoltage. When the threshold Is exceeded, an output pulse Is
generated and Is gated bU the computer, latching the address Information of
the screen RAM (horizontal and yertlcal counters) Into abuffer to be read by
the computer. In this way, the location of the pen on the screen Is determined
by the computer.
$12 $

PROGRAMMING TIPS
To best program for your Ught pen, Inkwell Systems advises reading your
computer manual and corresponding Programmer's Reference Guide thoroughly.
The following are general programming guidelines plus some specific
Information relating
to the Commodore 64 family of computers. It assumes
that the programmer has an understanding of Commodore 64 BASIC and at
least afamiliarity with
the principles of 6502 machine language.
• As discussed In previous chapters, the electron beam ·palnts· the picture
on the screen, and the VIC-II video controller chip keeps track of where the
beam Is on the screen. This chip monitors both the horizontal (X) and vertical
(V) positions.
• When the electron beam strikes the phosphor within the pen·s field of view,
the pen sends a pulse back to the VIC-II chip, which then saves the current X
and V pOSitions of the electron beam on the screen In the two light pen
registers. These registers are located at memory location 53267 (OOI3HEX)
for the Xlocation and 53266 (DO 14 HEX) for the Vlocation.
•
The light Pen Model 170-C nose tip switch Is configured to look like a
Joystick switch to the computer. It may be checked by looking at bit 2 of
memory location 56321 (OCO 1 HEX). When the switch Is closed, this bit w1l1
be zero (0).
• Some means of visual feedback Is Important for Interaction with the
operator .. Without this, It Is difficult to know whether the light pen Is aimed
properly. There are several ways this feedback may be accomplished. The
symbol the light pen sees may be flashed, IntenSified, displayed In Inverse
video, or marked with a cursor. Audio feedback, If available, Is also an
excellent means of acknowledging proper pen placement.
• There are two basic operational modes that are used with a light pen: the
pick mode and the track mode.
In the pick mode, the operator places the pen tip over the area desired and
actuates the switch. The operator then places the pen tip over another area
and again actuates a switch. Each actuation of the switch wtl1 cause the
software to perform some task, I.e., If drawing a straight line between two
points, the line starts at the first switch actuation and ends at the second
switch actuation.

PROGRAMMING TIPS'
In the tnlck mode, tI ttlrget (such tiS tI crosshnlr) Is genernted nnd dlsplnyed
with Its center locnted lit the Illst point seen. As the pen Is- moved on the
screen (or the second switch touched on Model 154-C), ellch new point Is
retained as pnrt of the line lind the tnrget Is kept centered as long as the
switch Is depressed.
• To overcome a light pen's Inability to register locnllon over a dark area,
the CRT mlly be flashed (the entire screen Is turned on) for one frame after
the switch hns been actuated. ThIs will provIde mnxlmum sIgnal for the pen
while being unnoticeable to the operator (as long as the number of flashes per
second Is kept low).
• If II color CRT Is being used, the color red Is equivalent to black due to the
red phosphor's long persistence. The blue phosphors have good response
chllrllcterfstlcs so the screen should be floshed with blue (or while) for
mllxlmum light pen response.
• Under certnln conditions, such liS lin e)(tremely noisy CRT, a noisy power
supply, pIcture Jitter, etc., the output from the light pen may vary with lime
for II given location. One way to control thIs Is to requIre two or more
consecutive hits to be mil de at the same localion before the localion Is
considered vlllld. This suggestion Is especllllly Importllnt If there Is no
control of the environment or system with which the light pen Is used.

The. fight. £PEJl DEMONSTRATION
DISK: GETTING STARTED
Set up your Commodore 64, 64C, SX64 or 126 computer, disk drive and TV or
monitor as described In their respective owner's manuals.
With the power OFF, disconnect anything connected to the joystick ports on
the computer. Install The light Pen by Inserting the connector Into the
joystick port marked "Control Port ."Iocated on the right side near the front
of the computer (or In the rear of the SX64). That Is all there Is to III
Tum on the computer first, then the monitor and finally the disk drive. At
this time you are ready to begin programming, running the Demonstration Disk
or using The light Pen with your favorite light pen compatible software.

LOADING ThE. fight tpm
DEMONSTRATION DISK
._ Follow the fnstructlons In the 6ETTlN6 STA~T£D section of this manual to
readliliour computer system and The light Pen.
Insert The light Pen Demonstratfon Disk and type:
a
LOAD •••• 8 <RETURN>
RUN <RETURN>
The followfng screen will appear.
Light Pen Demo Disk
I. Synthesizer
2. Light Pen Piano
3. Follow Mel
4. Where Am 17
5. Exit
Please make a selection
Hake your selection with The light Pen.
o
o
o
o
o
To EXIT II program on the Demonstratfon Disk and choose another program, you
must reboot.
PLEASE NOTE: For !l!!I!LCO~~L.J! b!ckj!l!.._ cQI!!U!.Ll.b!!.Jlght Pen
Demonstralfon DIsk l.s.J!rovl.!I.ed on thl!. back of the disk. For an additional
~y, J!UII9get.t~~~_.~!,.~~~~~!o~~~T~~CI<~~pdis~'be~lIdeuslng an!foij8'Qn~e,
Jlne copy prngrm:nS.avllllable on the martet today. The Demonstration Disk Is
NOT copy protected.