Return to CD Index
GemCad User's Manual
Version 4.51by
Robert W. Strickland
May, 1992 Revised August 24, 1992
HTML version of manual: January 22, 2001
Dedication
GemCad is dedicated to the memory of my father
Robert L. Strickland
who introduced me to faceting.
AcknowledgementsI gratefully acknowledge the many suggestions of Walter Carss, Bob Long, Norm Steele, Greg Thompson. I thank all of the GemCad users whose continued suggestions have helped me to improve the program. I thank my wife, Dorothy, who was patient with me while I put in the long hours on GemCad and helped me proofread this manual.
Copyright © 1992, 2001
Robert W. Strickland.
All rights reserved.
GemCad Manual Table of Contents
Tutorial
- Lesson 1
- Lesson 2
- Lesson 3
- Lesson 4
Reference Manual
Configuring GemCad- File Menu
- Cut Facets Menu
- Point Menu
- Edit Menu
- Utility Menu
- Diagram Menu
Error Recovery
Using GemCad with a Mouse
This manual describes GemCad 4.51, a computer-aided design program to assist in designing faceted gem cuts. GemCad simulates a faceting machine. You can specify angles and indexes, and GemCad will cut facets on the screen, drawing the stone at each stage. This is valuable for checking the validity of published faceting diagrams. Although GemCad simulates a faceting machine, its real purpose is to do the “grunt work” of designing new gem cuts. GemCad can figure out the angle of a facet given two points and its index, and it can figure out the angle and index given three points. You can specify meet points on the screen with the cursor keys or the mouse. GemCad understands radial and mirror-image symmetry. If you tell it to cut one facet, it will automatically cut the other facets on the tier. GemCad can scale a stone, adjusting the angles for different indexes of refraction. GemCad can turn a round design into an elliptical one. GemCad can produce formatted listings suitable for use as faceting diagrams.
GemCad is written in the C programming language and was compiled with Borland's C++. GemCad runs on an IBM PC™ or compatible with at least 512KB of memory and VGA, EGA, Hercules™ or CGA graphics adapter card. (The CGA resolution of 640X200 is a bit sparse, but is sufficient for many designs.) An 80x87 numeric co-processor is strongly recommended but not required. A hard disk is also strongly recommended. GemCad supports a Microsoft Mouse or compatible. The driver supplied with your mouse (such as MOUSE.COM) must be loaded before running GemCad. This is most commonly done in the AUTOEXEC.BAT file, but may be done anytime at the DOS prompt. GemCad will not work with a MOUSE.SYS device driver such as is loaded in the CONFIG.SYS file.
GemCad is an old DOS program. It will run in a DOS box under Windows 3.1, 95, and 98. A lot of the DOS stuff can be hidden behind Windows shortcuts.
To run the program, type GEMCAD at the DOS prompt. The program will try to detect which kind of graphics adapter card you have, but if your screen is messed up, try again by typing GEMCAD X where “X” specifies the graphics adapter and is one of the characters “c” for CGA, “e” for EGA, “h” for Hercules, ”v” for VGA. This will bypass the auto-detection software and will hopefully get things going in the right direction.
GemCad can be “driven” with the function keys, legends for which appear at the left of the screen. Legends beginning with “>” change to a new menu of functions. You can also point at a function key legend with the mouse and click a mouse button to activate it. The Help (h) key (Function key F11 [or Shift-F1] in every menu) followed by another function key will print a short description of what that key does (when it is NOT preceded by the F11 key).
To install the program onto your hard disk, I recommend making a subdirectory called GEMCAD on your hard disk and then copying all of the files to that directory. If your hard drive is C: and your floppy is A:, do the following at the DOS prompt:
C:
CD \
MD GEMCAD
CD GEMCAD
COPY A:\*.*
Return to CD Index
