Daxcad

Daxcad

DAXCAD (CAD) DaxCAD is a 2D Computer Aided Drawing software application written in the early 1980s by Practical Technology Ltd.

Contents

Introduction

A nice screen shot of Daxcad on the PC

DaxCAD was and still is a CAD Package used by a handful of companies throughout the world in the late ‘80s and early ‘90s. It origins stem from Paisley College of Technology, now known as Paisley University.

DaxCAD was written to be an inexpensive, simple to use CAD application for a range of industries. It was sold in many sectors from government to insurance

DaxCAD’s main design strength was its simplicity. At that time CAD applications were expensive and difficult to use. DAXCAD offered simplicity with complex drawing functions at fraction of the cost of similar systems.

History

The project DaxCAD was started by and was the brainchild of Kirk Ramsay, a senior lecturer at Paisley College. He had started a small software company, Practical Technology Ltd in Glasgow around 1984.

The company was founded at a time when CAD was starting to become more commonly available in the form of downsized workstations. The intent of the company was to ride the wave and make as the name suggests, technology practical.

After looking at the existing market offerings for CAD, namely DOGS and CV (ComputerVision), Kirk felt that there was a space for a product which was cheap and easy to use, as both of these packages were enormously expensive and rather hard and complex to learn. The cost of a single Computer Vision workstation could be £50,000 which made it inaccessible to all but very large companies.

The base platform chosen was Apollo. Apollo was a UNIX implementation similar to Sun. The language chosen for development was Fortran 77. Interestingly the Apollo workstation Operating System - AEGIS was written in Pascal.

With funding from the Clydesdale bank in place and a small team of local software engineers recruited from Paisley Tech - development of the code began. Apollo offered good quality graphics and within 12 months - DaxCAD Version 1 was ready to be released. A sales team was assembled and DaxCAD was launched.

After a year it was also obvious the PC was fast becoming a second and cheaper alternative to Apollo. Practical Technology found themselves having to plan to downsize an already downsized product. The plan for PC DaxCAD was hatched. It was an ambitious plan by any standard. To take Fortran 77 code and port it on a PC. Thanks to Microsoft, early PC systems had substantially limiting memory and graphics capabilities. DaxCAD had been designed to run on Unix with superior memory capabilities. After a year of hard work - DaxCAD PC was launched. It proved to be a success but the software was large and unwieldy. A complex arrangement of overlays using Pharlap meant that the software was slow and unstable. It also meant having to keep two distinct versions of the software as Intel and Motorola processors were designed differently.

The code became littered with a crude form of pre-processors – It marked out the code using the fortran comment command "C" So if you wanted the code to be available for a PC ( IBM ) then you would surround the code with CIBM. For Apollo - CAPOLLO. Later versions included Sun and there were specified processors for that as well.

And of course the dreaded device drivers had to be written to support mice, monitors, graphics cards. During this period – RACAL – who had an electronic cad system licensed the use of DAXCAD to be part of their system. DaxCAD would be used to design the circuit boards and other mechanical components – Racal Redboard

DAXCAD Macros

The DAXCAD Macro facility was one of the more powerful features. It also meant that functions could be added by users without major redevelopment. In a move well ahead of its time, BASIC was chosen as a language platform. AutoCAD chose LISP - also powerful but outside the capability of most users. BASIC was something most engineers could use. A perfect example is the illustrious ellipse macro. Apart from the "*" character as a comment - it conforms to a standard BASIC structure. Note that since DAXCAD was based on a VERB - NOUN - MODIFIER command structure - the words that were programmed into the menus could be entered directly into a macro.

This Macro draws an Ellipse - simple and effective

 
*******************************************************************
* DAXCAD MACRO TO DRAW AN ELLIPSE AS A CONTINUOUS SERIES OF LINES *
*******************************************************************
*user inputs: centre of ellipse, lengths of axis & angle of Major Axis
INSERT CONTINUOUS
PRINT "Indicate the centre of the ellipse"
GINPUT
XC=X
YC=Y
INPUT "Enter the Length of the Major Axis";MAJ
INPUT "Enter the Length of the Minor Axis";MIN
INPUT "Enter the absolute angle of the Major Axis";B
*
*Step through increments of angle A radians about the centre of the ellipse
        FOR A=0 TO PI(2) STEP PI(0.02)
        *("STEP" can be varied to give more precise or quicker ellipse
        *Ellipse centred on X0,Y0 (Major axis at 0 degs.) is locus of point P where
        XP=MAJ/2*COS(A)
        YP=MIN/2*SIN(A)
        *Adjust for the indicated centre of the ellipse and angle of the axes
        GINPUT X(XC+XP*COSD(B)-YP*SIND(B)),Y(YC+XP*SIND(B)+YP*COSD(B))
        NEXT
VERB_MENU

More complex - A Macro to draw a CAM from two circles

 
 
*******************************************************************
* DAXCAD MACRO TO CALCULATE AND DRAW SIMPLE HARMONIC CAM PROFILES *
*******************************************************************
*user inputs: centre,start angle,length of curve,start and end radii
INPUT "Do you wish to continue with Cam Profile Macro (Y/N)";A$
IF (A$.EQ."N") THEN GOTO L99
IF (A$.EQ."n") THEN GOTO L99
IF (A$.EQ."Y") THEN GOTO L1
IF (A$.EQ."y") THEN GOTO L1
GOTO L99
&L1
INSER CONTINUOUS
PRINT "SHM: Indicate the intersection of the radial centre point"
GINPUT
XC=X
YC=Y
*
INPUT "SHM: Enter start angle (Degrees)"; STA
INPUT "SHM: Enter start length of cam profile position (Degrees)"; STA
INPUT "SHM: Enter included angle of cam profile position (Degrees)"; LOA
INPUT "SHM: Enter start radius"; R1
INPUT "SHM: Enter end radius"; R2
INPUT "SHM: Enter angular step increment"; STI
*
 
RAD = 3.141593/180
*
* length of curve in radians
LAR = LOA*RAD
*
*calculate roller displacement
DOR = (R2-R1)/2
*
*Get Number of Steps
TNS = ABS(LOA) / ABS(STI)
*
*sign the step incrementas LOA
STI = SIGN(STI,LOA)
 
FOR A=0 TO TNS
*current angle increment
 
CAN = A*STI
* temporary value
TMP = PI(1)*(CAN/LAR)
*calculate the displacement of roller
IRD = DOR * (1-COSD(TMP))
*new radius
NRA = R1+IRD
*calculate vector
XP=XC+(NRA * COSD(STA + CAN))
YP=YC+(NRA * SIND(STA + CAN))
*OUTPUT LINE SEGMENT
GINPUT X(XP), Y(YP)
NEXT
&L99
VERB_MENU

This image shows how the above macro draws a Cam between the two concentric circles.

The above Macro draws this Cam between the two concentric circles

DaxCAD industry sectors

Software today

The DAXCAD software today is a registered sourceforge project and can be located at http://sourceforge.net/projects/daxcad. The code is based on a mixture of Fortran 77 and ANSI C. C++ was never used. DAXCAD also has a built in BASIC interpreter and during it life, many macros were written to automate various drawing office tasks.

DAXCAD capabilities

The capabilities of DaxCAD include:

  • 2D Drawing
  • Paper based modeling
  • Exporting of drawing to DXF Format
  • Export File formats to Misomex, PEPS, GNC, IGES and Interleaf
  • Plotting in Postscript, HPGL and Calcomp formats
  • Importing DXF, ComputerVision, GENIO, PathTrace , GERBER
  • Automatic boundary calculation for hatching and NC Output
  • Vector based calculation engine
  • BASIC Style macro interpreter for automation
  • References for components and symbols
  • ISO Dimension
  • Property tagging - Bill of Materials reporting
  • 8 Bit Color mapping

Software technologies

DaxCAD is written in the following languages

  • Fortran 77
  • ANSI C

DAXCAD has its own Macro interpreter which is a form of BASIC.

To compile and run DAXCAD Cygwin is the recommended platform. DAXCAD uses X Window as its graphics engine. The software will compile using the GCC ( G77) compiler and the GCC compiler.

Hardware and OS technologies

DaxCAD ran on PC based and Unix based systems

1984 - 1994

  • Apollo AEGIS
  • Sun SunOS
  • Sun Solaris (Advent)
  • HP HP-UX
  • Sony
  • Intel PC DOS Based 286
  • Intel PC DOS Based 386

2001–present

  • Windows 2000, 2003, XP, VISTA
  • Linux Various
  • Solaris 10 Intel (Protoype)

Using DAXCAD

See also

Other related topics

References

External links


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