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Using Accucadd with digitizing tablets
Although most people use a mouse, Accucadd is also designed to work with
digitizing tablets. One use for such tablets is in "tracing" artwork into your
Accucadd drawing. Such tracing can be done in a way that preserves the size -
see the Accucadd Reference Manual, section 6: Setup - Set Digitizer
(page 6-23), for more
information.
Set up the tablet under Windows
The digitizer is handled by Windows, and not by Accucadd (which was not the
case with our previous RoboCAD programs), and so the first thing you must do is
get the digitizer working under Windows. This may involve a number of
steps.
- Check for, and remove if necessary, any conflicting drivers (e.g. a "tablet mouse driver"
that makes your digitizer "look like" a mouse). Check with the digitizer
manufacturer if you are unsure about compatibility issues and how to resolve
them.
- Install the digitizer Windows driver(s). Note that RoboCAD digitizer
drivers will not work with Windows - you must use a Windows driver. Be sure
sure to use the correct one(s) for your Operating System – Windows 98 drivers won’t work with Windows NT or
windows 2000. Windows ME divers don't work with Windows XP, and so on. Check
that you are using the latest version. Drivers and operating systems can both
have problems, and these are often addressed in updated version of the driver.
You will usually find these available on the digitizer manufacturer's web
site.
- Many digitizer drivers will allow you to switch modes - that is, switch
between using the digitizer as a mouse (relative) or "original digitizer"
(absolute or position) mode. To use the digitizer to trace a drawing you will
need to set "digitizer" or "absolute" mode, and not mouse mode. When you are
done digitizing you may wish to change modes and use the digitizer as a mouse
to control Accucadd - this is personal preference. Your digitizer driver will
typically allow this, as shown in the CalComp DrawingBoard III TabletWorks
driver, below.
- The next step is mapping the screen to the tablet surface. This determines
how far, and in what direction, the screen cursor moves when you move the
digitizer puck or pen. Note that "out of the box" the tablet driver may not be
set for equal motion in the X and Y axes (because of the way mice have
historically operated). You will want to set it up so that it is equal in both
axes, and also ensure that you can cover the whole screen. If you change your
screen resolution (e.g. from 800 x 600 to 1024 x 768) you will also have to
change this mapping. The example, taken from the DrawingBoard III TabletWorks
driver, shows 12000 digitizer units in the X direction mapped to 800 pixels,
and 9000 units mapped to 600 pixels in the Y direction. Notice that 12000/800
= 9000/600 for equal X and Y scaling. You may also spot that the Y axis is
inverted (9000 to 0 instead of the other way around) to conform to the usual
convention that moving "up" the screen is a positive move (increase in
coordinates).
Set up the tablet scaling for Accucadd
Now you have the tablet set up under windows, start Accucadd, and go to the
Set Digitizer menu (below).

Fix a piece of paper to your digitizer. Draw on it a horizontal line of known length
- say 9 inches. Digitize the line, following the Accucadd prompts, then key in the real world length of that line,
as shown.

Accucadd "zooms" so that your screen view is now set to preserve the real
world size of the design you are tracing. Should you loose this calibration,
perhaps by using Zoom or Redraw, you can always repeat it any time.
Above and beyond...
The CalComp DrawingBoard III TabletWorks driver has some additional features
you may wish to use. We suggest that you set up the "puck" buttons, as
shown below.
| Button # |
Function |
|
0 |
Left Click |
|
1 |
Left double click |
|
2 |
WYPIWTG <- -> Standard |
|
3 |
Right click |


This document was prepared using the CalComp driver detailed below:

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