Marconi RB2/PC-1 User manual

USERGUIDE
FORTNE
BBC Micro Model 'B' Version

CONTENTS
Para. 1 Welcome
Para.
2
Intro
Para.
3
Connecting Up
Para. 4 Software Description
Para.
5
Loading and running the Utilities Software
Para.
6
Loading and running drawing program Paintball 1
Para. 7 Transferring to disc
Para. 8
Specification
Para.
9 User
Port connections
Para. 10 Maintenance

I. WELCOME TO THE 112 TRACKER BALL
This booklet and the cassette tape that
goes with it will help you to get your
Tracker Ball working and show you how
versatile and accurate the Tracker Ball
is
in positioning the cursor on a video
display.
Forthe more advanced user, this booklet
contains technical information which
explains how the Tracker Ball works and
ways in which
it can be programmed.
Firstly check that the box contains the
following:
• Tracker Ball with inbuilt connecting
cable.
• Tape cassette containing the Utilities
program.

2. INTRODUalON
Thefunction ofthe TrackerBall is to actas
a pointing device to move the cursor on
the video display.
Tracker balls evolved from joysticks, and
are so accurate that the Tracker Ball is
now recognised as the ultimate device for
quick and precise control ofa cursor.
The Marconi RB2/PC-1 TrackerBall has
been designed for the BBC Micro Model
'B' version and contains three user
assignable buttons which can replace
existing keyboard key functions oract as
additional keys specially assigned by the
user.
The tape cassette supplied with your
Tracker Ball provides a Utilities program
which allows you to run many ofyour
existing programs but using the Tracker Ball
instead of cursor keys, joysticks or
·mouse'. The tape also provides a
demonstration drawing program
Paintball.
To see how versatile and accurate your
Tracker Ball is follow the next few pages
of the booklet.

3. CONNEOING-UP
As a minimum you will needthefollowing:
e BBC Micro Model 'B'
• Cassette player
• Monitor
or television set
• TrackerBall
• Tape cassette
The booklets supplied with your BBC
Micro Model 'B' will tell you all you needto
knowaboutconnecting up the BBCMicro.
cassette player. disc drive unit and
monitor (or television set).
Before connecting up the Tracker Ball.
make sure that the electrical supply is
disconnected
or switched off.
Connect the Tracker Ball into the
connector marked ·user port· on your
BBC Micro Model 'B'. This connector is
underneath the keyboard in the centre
position.
Switch on the electrical supply. You are
now ready to load the software.

4. SORWARE DESCRIPTION
Note: This software is suitable for BBC
Operating systems 1.0 and above.
Enclosed with the Tracker Ball
is a
cassettetape, with programstoallow your
Tracker Ball to beused with your BBC
Model 'B' Microcomputer. The tape
is
titled SOFTBALL.
Side1
1. A utilities program which assembles
machine code cursor control and
joystick simulation programs. It also
provides a utility to allow the user to
includeaTrackerBall facility
in hisown
program.
2. A demonstration drawing program,
called Paintball, which allows the user
to create complex graphic displays
using the Tracker Ball.
Side2
1. A version of the utilities program
suitable for saving
to disc.
2. A slightly modified version ofthe
demonstration drawing program on
SIDE
1.
1. Utilities Program
This allows the userto substitute Tracker
Ball
a) As cursorcontrol
in place of cursor
keys. This
is particularly good with
Wordwise and
in general program
editing.
b) As replacementforthe joystickused in
certain compatible games.
c) Finally, a specially written utility is
provided for inclusion
in user-written
programs.
Cursor Control Utility-
TRACKER BALL
The cursor control option provides full
control overthe editing cursor using the
Tracker Ball instead ofthe cursor keys.
This is useful for word processing, e.g.
in
conjunction with Wordwise. The program
also assigns the DELETE, RETURN and
COPY functionstothe three push buttons
on theTrackerBall. Alternatively, the user
may assign his own choice of keys to
these three push buttons. The only keys
notpermitted are ESCAPE, CAPS LOCK.
SHIFT LOCK. CONTROL, SHIFTand
BREAK.

Joystick Simulation Utility-
JOYSTICK
This routine is intended for use with those
games and otherprograms which would
benefit from the use ofTracker Ball as an
alternative to a joystick. The routine also
allows a user-written joystick program to
have a Tracker Ball alternative by
including the BASIC ADVAL() function or
using OSBYTE & 80.
Userwritten programs -DIRECT
A programmerwho wishes to build the
Tracker Ball into his program would
normally assemble this utility and save to
disc
or tape. It is then ready to assemble
into his program when convenient.
Which joystick programs will work
with RB2 Tracker Balls?
First, since the above utilities use 256
Bytes
of memory when loaded, it is
necessarythatanyjoystickprogram tobe
run doesnotoccupythewhole memoryof
the BBC.
Second, the above utilities must not be
loaded into amemorylocationused bythe
joystick program to be run. The utilities
program helps here by offering the user a
choice of memory locations likely to be
available. The correct choice is found by
trial.
In most instances the &900 location
is suitable.
2. Demonstration Drawing Program
Paintball
Paintball is a versatile but user-friendly
package which allows the usertocreate
four-colour drawings with the aid of the
RB2 TrackerBall. Both text and graphics
can be fully mixed and the results can be
saved to tape
or discfor future use.
The package
is very easy to use, thanks
to the use ofamenuandthe RB2 Tracker
Ball, which vastly speeds up cursor
positioning.
Cursor Control
The cursorcontrolled by the Tracker Ball
is central to Paintball. The cursor is used
for positioning and drawing points and
also for helping to select options from the
menuwhich is on the right handsideofthe
screen.
The TrackerBall functions as the
sole input most of the time.

Buttons
The ball moves the cursorand the left
hand and centre buttons are used as
·select' buttons. The right hand button is
important.
When it is pressed the X and Y
co-ordinates of the cursor are displayed.
If a
shape is being drawn the distance D
from the lastpoint to the cursor is
displayed.
For a circle the radius R is
displayed.
Colours
Four colours are allowed on the screen at
any time. The colours are accessed via
the bottom
four buttons of the menu. Each
of the colour boxes is split into two. When
the left hand portion is selected, that colour
becomes the ·current' colourandthe 'ON'
is displayed.
When the right hand portion is selected,
the next colour in a sequence of four
replaces the selected colour. A further
push on the button selectsthe nextcolour
and so on.
NOTE: The colour selected cannot be a
colour already on screen.
Text
Text can be typed in from the keyboard at
any time. If the text is not overthe menu
then it will be printed on the screen at the
cursorposition.
The text can be positioned on the screen
by moving the Tracker Ball. Pressing a
·select' button freezes the text.
Text can be ofthe normal type
or of a
special compressed type which is only
available in uppercase. The compressed
text is accessed by holding down the
CTRL key while typing.
Menu functions available
GRID: When selected, a grid of points is
superimposed on the screen. This is to
help with alignment. Selecting GRID
again takes the grid away.
The GRID function should be used with
caution sincegrid pointsdrawnoverwhile
the function is on will reappearwhile the
function is switched off. See also section
6.

SOLID: Circles, triangles and oblongs
will be drawn
in solid if this function is
selected, as well as the shape function.
Otherwise they will be drawn
in outline.
CIRCL: When selected, a circle may be
drawn by first defining its centre, then any
point on its circumference.
TRNGL: When selected, a triangle may
be drawn by defining three cursor points.
OBLNG: When selected, an oblong may
be drawn by defining two diagonal
corners.
LINE: When selected, a line may be
drawn
by defining two points. Rubber
banding is employed for ease ofuse.
DRAW: When selected, the usermay
draw free-hand. This is achieved by
moving the ball, while holding down a
·select' button with the other hand.
FILL: After selection, an enclosed shape
may be filled by positioning the cursor
inside the shape and pressing a ·select'
button. To stopfilling, press ESCAPE key.
Note:
It is only possible to fill overthe
background colour, that is, the colour
shown
'ON' in the bottom colour box.
CLEAR: This resetsthe menu and clears
the screen to the background colour.
LOAD: This will load a named drawing
from disc or tape on to the screen for
further use. See also section
6.
SA VE: This will save a named drawing,
along with its colour palette to a disc or
tape for future use.
USER: This function is left blank to allow
a programmer
to add afunction ofhisown
choice, e.g. a screen dump routine. The
USER function may be intercepted as a
procedure at line 6500 in PBALL 1.
The result
of selecting USER on the
standard unmodified system is merely to
reset the menu.
CAT: This is a catalogue function
available for disc systems only. When
selected, a catalogue ofthe disccontents
is displayed for three seconds.