The CAD System
             Version 4.0
                 by
            Stephen P. Nye
        Copyright (c) 1984,1987

**************************************

     Version 4.0 is the latest version of the popular CAD package. It includes a number of major improvements over Version 3.0, including:

  a modified command structure based on a pull-down menu.

  an ML command processor that reduces drive access by about 50%.

  onscreen help for all drawing functions.

  screen compression routines in both horizontal and vertical directions.

  the ability to display both hires screens onscreen at the same time.


DOWNLOADING CAD VERSION 4.0

     CAD Version 4.0 is available only through the CBMART SIG of CompuServe Information Service. It is located in DL12 as three files; CAD401.BIN, CAD402.BIN,
and CAD403.BIN. These files are Self-Dissolving Archives so no additional programs or special filenames are necessary.

     To obtain the complete CAD Version 4.0 follow these steps.

1. Download the three files to a freshly formatted disk as CAD401, CAD402, and CAD403.

2. Prepare a second freshly formatted disk; this second disk will become the CAD system disk.

3. Disable any fast load cartridge or program you may have in place. 'LOAD CAD401,8', place the system disk in the drive, and RUN the program. CAD401 will
create the first portion of the CAD package on the system disk.

4. Follow the same load-swap disk-run procedure for the remaining two files.

IMPORTANT NOTE: The three files should be run in sequence so the programs will be written on the system disk in the proper order.

     When creation of the system disk is complete, the CAD40x files can be scratched or stored for backup. It would be wise to copy the system disk for
backup and write-protect the working copy.


LOADING CAD VERSION 4.0

     To load the CAD system into the computer, simply type 'LOAD"0:*",8' and RUN. If the files were dissolved in the proper order, the first program on the
system disk is 'BOOT'.

     The system will prompt you for the number of drives in your system. If you are using a two drive system, press return to accept the default assignment.
If

you are using a one drive system, press '1'. In either case, CAD detects which drive you booted from and assumes the system disk will be in the boot drive.

     The default can be changed by modifying the BOOT program. The first line of the program contains the default setting, and a REM statement informing you
what to change.

IMPORTANT NOTE: In a two drive system, there is NO time when the system disk should be removed from the boot drive. With a one drive system, DO NOT remove the
system disk unless prompted to do so. CAD is still very disk intensive, and continually returns to the disk for more program information. If the system disk
is

not in the drive the program will crash. (See the notes at the end of this file for information on handling of program crashes.)

     The system will load several support files and the title screen will appear. Shortly thereafter the main menu will drop down. This menu MUST be visible
to

exit any command function, and is pulled down by pressing 'F7'. In most cases, if you press F7 by mistake, pressing it again will return you to the previous
function. However, due to the command structure, you may have to re-enter some functions by pressing the appropriate key at the main menu.


     Each drawing command now has a separate help screen. These screens are  accessed by pressing 'F8'. Each screen will describe the command keys available
in

that function, and how to use the associated function. When you are finished viewing the help screen, press any key to return to the draw command.

     From the main menu a general help screen is available. This general help screen will inform you of the keys that are available within most draw
functions.

Since these keys are of a global nature, they are not described in the individual help screens.

     The global command keys are:

!  switches between the two hires screens.
#  inverts the visible hires screen.
&  adds the second hires screen to the visible screen. The second hires screen is unaffected by this operation.
=  copies the visible hires screen to the second hires screen. The data in the second screen is lost.
DEL  deletes the last operation performed.
        CLR will clear the visible screen.
F7  will pull down the main menu.
F8  will display the help screen for the function you are presently using.


What follows is a brief description of each function. Consult the function help screen for additional information.

a - will draw a scaled half-circle counter-clockwise from the first point marked to the second.

A - will draw a broken line from the first point marked to the second. You will be prompted for the length of the line segments, and the length of the space
between segments. If you wish to change these values, you may restart the function by pulling the menu and pressing 'A' again.

b - will draw a box using two marked points as opposite corners of the rectangle. Within this function, if you press 's' the boxes will be filled (solid). To
return to hollow (line) boxes press 'l'. Lined boxes are the default.
c - will draw circles using two points. The default uses the points to determine the diameter of the circle. Press 'r' (radius) and the system will use the
first point as the center of the circle, and the second to determine the radius. Pressing '+' will toggle a small cross at the center of the circles.

C - compresses the screen. Pressing 'h' will compress the screen horizontally. Pressing 'v' will compress it vertically. And pressing 'b' will compress in
both

directions. There is no help screen for this function.

d - will draw a filled circle using two points to determine the diameter of the circle. Pressing 'e' will set the system to erase the area, pressing 'd' will
set the system to fill (draw) the area.

e - will erase a rectangular area marked with two points as in 'b'. Pressing 'l' will set the system to erase a line, pressing 'b' will set the system to
erase

a box (default).

f - will enter the figure command. This command uses the figure libraries that are available in DL12, or a library that you previously constructed. The system
will prompt you for the File disk drive, and display the default condition. Press RETURN to accept the default, or enter the number (8 or 9) of the drivein
which you are placing the figure library disk. You will then be returned to the hires screen. To place an object onscreen, press the key that corresponds to
the object. That object will be transferred to the cursor. Move the object into place and press the firebutton to place it onscreen and return to the
crosshair

cursor. If you wish to use the same object again, just press the firebutton and the cursor will be replaced again with the object. To use a different object,
press the key associated with that key. You may also rotate the figure 90 degrees at a time by pressing the British Pound sign key.

F - will access the freehand draw mode. Pressing the firebutton will toggle the draw mode on and off. Pressing 'e' will move the system into freehand erase
mode. Press 'd' to return to freehand draw mode.

g - will place the system in fill mode. Move the crosshairs within a closed area, and press the firebutton. The area will be filled with the foreground color.

G - will overlay a grid on the hires screen. This grid cannot be removed once added, so you are prompted before the drawing occurs. If you wish to continue,
press 'y'. Enter the spacing between the verticle lines and spacing between horizontal lines, and the system will draw a grid onscreen. There is no help
screen

for this function.

h - will draw a hexagon using two points to determine the width of the figure.

i - will turn on the onscreen rulers at the left side and bottom of the screen. There is no help screen for this function.

I - will turn off the onscreen rulers. There is no help screen for this function.

j - is used for drawing fanouts on electronic schematics. All lines will be drawn from the first point marked, first horizontally, the vertically, to the
cursor. To reverse this order, press 'v'. To return to the default press 'h'.

k - will draw an ellipse using three points. The first marks the horizontal axis and one side, the second marks the other horizontal limit, and the third the
vertical limit.

l - will draw a line from the first point marked to the second. Several brushes are available for this function. To use a brush, choose the appropriate key
from the help screen, and press that key.
To draw lines from a common origin, press 'R' (upper case). The first point will mark the common origin. To change the origin, move the crosshairs over the
first point and press the firebutton. This will free the first marker so you can relocate it. To return to the default press 'L' (upper case).

n - will enter the enquire function. This command allows you access to information that would otherwise not be accessible within CAD. You will first access
the

hires screen. Here you may mark two points to determine the distance between them. If you do not wish to use the measure, press the firebutton twice. The
system will display a text screen with information on colors, drive assignments, etc. When done, press F7 to return to the hires screen and pull the menu.

o - will access the zoom command. The cursor will change to a box. Move this box to outline the area you wish to zoom in on and press the left arrow at the
top

left corner of the keyboard. This key will toggle between the hires screen and the zoom screen.

O - is the stamp function. Move the box cursor over the area of the screen you wish to use as a stamp, and press 'p' to pick it up into the cursor. Pressing
the firebutton will transfer it back to the hires screen.
The following keys work in this command:

'h' will flip the cursor horizontally
'v' will flip the cursor vertically
'i' will invert the pixels in the cursor
'a' will cause the cursor to be logically ANDed with the hires screen
'o' will cause the cursor to be logically ORed with the hires screen
'x' will cause the cursor to be logically Exclusive ORed with the hires screen
CLR will return the box cursor

p - uses three points to draw a parallel-o-gram. If the fourth corner will be offscreen the system will not draw. The order that the three points are drawn
will affect the shape of the figure, so practice may be in order.

P - draws lines using Polar co-ordinates. Move the cursor to one end of the line segment and press the firebutton. You will be prompted for the length of the
line segment (R) and the number of degrees off the horizontal (Theta). Enter R in inches and Theta in degrees.

Q - will quit CAD and reset the computer.

r - will draw recti-linear lines. that is, all lines will be drawn from the first point marked, horizontally then vertically to the second.

s - will enter the snap command. All lines will be drawn horizontally from the first point to the second. To change the line orientation, press 'v'. Pressing
'h' will return to the default condition.

t - is the text command. This command functions much like the 'f' command, but each time a figure is chosen the cursor is automatically moved to its new
location. You will be prompted for the file drive assignment, the character spacing in pixels (number of pixels between figures) and the line spacing. You can
rotate the figure placement by pressing the British Pound sign key.

T - allows you to transfer a portion of the hires screen to another location, or to the second hires screen. The size of the area is limited to one screen.
Mark diagonally opposite corners of the area to be moved into the buffer. When the area has been copied into the buffer, move the cursor to the top left
corner

of the location you wish to move the area into. Note that the buffer keys off the top left corner of the area regardless of how you marked the corners. The
following keys are active in this command:

'a' causes the buffer to be ANDed with the hires screen
'o' causes the buffer to be ORed with the hires screen
'x' causes the buffer to be Exclusive ORed with the hires screen
'h' flips the buffer horizontally
'v' flips the buffer vertically
'r' flips the buffer in both directions
'n' returns to normal positioning

u - allows you to draw a border onscreen to mark the area of an RLE picture. You can use this command to erase a border by pressing 'e'. Return to the default
draw mode by pressing 'd'.

v - allows you to view both hires screens onscreen at the same time.

w - moves to a waveform menu. This menu contains commands to draw various waveforms. Each waveform is drawn in the same manner. Mark the first point, which
will determine the beginning and axis of the waveform. The second point marked will determine the amplitude and period of the waveform.

W - is the window command. This command allows you to pick up a section of the hires screen and place it elsewhere. Move the cursor over the area you wish to
move and press the firebutton to pick it up. Pressing the firebutton again will place the information on the hires screen.
You may also save the section as a figure in a figure library by pressing F2 and answering the drive and filename prompts.

x - will crosshatch a rectangular area marked by two points as in the 'b' command. You will be prompted for the spacing between the lines, and whether the
lines should be oriented horizontally or vertically. The defaults are highlighted.

y - allows you to mark the horizontal or vertical location of an object on screen 1 by placing a mark on screen 2. Press 'v' to mark the vertical location,
press 'h' to return to the default horizontal location.

z - will draw a border around the hires screens. There is no help screen for this function.

Z - will erase the border drawn by 'z'. There is no help screen for this function.

F1 - will load a hires screen. You will be prompted for the file type and filename. The following filename conventions are used in CAD:
  RLE files are suffixed with '.rle'
  Hires (33 block) hires files are suffixed with '.hr'
  Doodle files are prefixed with 'dd'
  Compressed Doodle files are prefixed with 'jj'
These filename extensions are added by the system if not entered.

F2 - will save a hires screen. You will be prompted for the file type and filename. The same filename conventions apply as with the F1 command.

F3 - will access the disk commands.

F4 - will access the color change function. From within this command you may change the colors of the border, background, etc.

F5 - will access the print menu.

F7 - will pull the menu. This menu must be visible to exit a function.

F8 - will access the online help screen where available.


IN CASE OF EMERGENCY

     Should the system crash for whatever reason, all is not lost. 
DO NOT TURN OFF THE COMPUTER!
If your computer is equipped with a reset button, reset and re-boot the CAD system. If it is not so equipped, press RUN/STOP-RESTORE. You will have to re-boot
blind as the screen will not echo what you type. Access a draw command ('l' for instance) and BEFORE pressing the firebutton press '!' to switch the screens.
The hires screen you were working on should be intact and you can continue drawing. Any data previously in the second screen is lost on re-boot.


CREDITS

     A number of people were involved in conceiving, developing, and testing various sections of Version 4.0, and I want to extend my gratitude to all of them
for their assistance. In particular:

Jake Lund for his ML work in conjunction with the RLE file load and save.

Brent Dane for his excellent ML modification of the figure routine, and his programming of the Window and Transfer functions.

Ray Bowman for the numerous outstanding figure files he created for use with CAD.