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Electronic Design Software

Wed, 04/09/2008 - 22:06 — gives

This page originally facilitated getting mostly MS-DOS-based Pspice and a couple of other locally used ECAD packages into UN-L E.E. student hands, so I wasn't wasting time copying floppies for students. Much has changed in the last few years and that software is now obsolete. For the newest, latest, greatest ECAD stuff, EE folks should nip on down to the bottom of the page where I've put links to all the design, simulation, etc. software I've been told about. A small archive that includes some other older tools can be browsed here.

PLEASE NOTE: I am not an expert on any software listed here.

Index:[PSpice] [PADS] [ AutoCAD-PCB]  

PSpice

Pspice got purchased by Orcad, and they still distribute some version as "studentware" for free: see this download page. And somebody has archived the old Windows 3.1 version:
spice6w1.zip
spice6w2.zip
spice6w3.zip

PADS Schematic and PCB

As an alternative to the Altium software used in the UNL EE Labs, we used to suggest that students wanting to work at home use a freeware version of the MS-DOS-based PADS Logic & PADS PCB.

It was not as well documented as a commercial program, and the user interface is very non-intuitive. And, plenty of students have never even seen a PC running MS-DOS outside of embedded systems like cash registers in stores. But it is quite powerful, has large parts libraries, and was used in the EE Shop for some of our projects.

(NOTE: Since we now use Protel for our work, I have not used PADS in some years and am not an on-line authority for questions.)

It has a limit on the size of the designs it can do. It supports a lot of output options and can generate Gerber photoplot files that can be used by the E.E. Shop IBC Boardmaker system. To learn about the current commercial version, see PADS Website.

Where to get it . . .
You can download compressed archives of these floppies right now from the Web, but there are some special considerations with the PADS files that other archived files don't have and that you must take into account to be able to install it on your machine. IT IS DESIGNED TO RUN UNDER MS-DOS IN FULL-SCREEN MODE; don't count on being able to run it "under" MS Windows in a command window, and I'd be surprised to see it work even booted to a Command Prompt on any version of Windows after 98, or maybe even 3.1. But if you're still determined, To download the three PADS disks:

    • These are archived images of the installation disks that MUST be uncompressed to floppy disks in a certain way before you can use them to install PADs. The program PKUNZIP must be in your computer's path to unpack these. The EE PC lab computers should have PKUNZIP on them.
    • Make sure you are in the directory on C: that you downloaded the files into. Now put a floppy in a drive and change to that drive. We'll assume you are using drive A:, so put the disk in A: and type
      A: [Enter]
    • Unpack the downloaded archives with the command
      PKUNZIP -D C:PADSLOG
      Repeat for the other two archives using "C:PADSPCB" and "C:PADSLIB" on the command line instead of "C:PADSLOG": each of the three files will require it's own floppy. The "-D" switch on the line recreates the directory structure needed on the floppy disk, and without this the program will not be installable.
    • Now you have the installation disks. The PADSLOG and PADS PCB disks both have a program named PINSTALL on them that you run to install the programs. It's pretty self-explanatory, but be advised that you have to perform the "Hardware Installation" for both the Logic and PCB packages before you run them. VIDEO TIP: many VGA adapters seem to work fine with the Paradise 800x600 setting in PINSTALL.
    • What about instructions? The PADSLOG and PADSPCB disks each have a file named DOCS.EXE on them, but they are not identical. They are self-extracting archives of the tutorial files and PINSTALL does NOT copy them over when installing the program. Put each of the two floppies into the drive in turn, make sure that you are in the PADSDEMO directory on C: (that's the default directory) and then type A:DOCS [Enter] You will end up with files named MANUAL.LOG and MANUAL.PCB. These are NOT comprehensive reference manuals: they are each tutorial files about 40 pages long. You are advised to read them and do the examples. PADS is NOT a program that you can just run and figure out on the fly.

      A Few Tips . . .
      A few hints to reduce frustration when first using PADS can be read here.

    • Incidentally, to run the programs you have to use the batch files provided: type LOGICS [Enter] to run PADS Logic and PCBS [Enter] to run the PCB program.
    • I got the following e-mail regarding PADS installation on newer, faster systems: "...this time of re-installing Pads from the floppies, it would not install and I would get an error of "Could not find this file. May not be in Path." when it tried to copy the files off the floppies. Something in my start-up was running the set up too fast, and the set up couldn't keep up (or so it appears), as the programs were not being copied from source to destination but the set up program thought it had. Doing a Shft-F5 at start-up (or reboot) to a clean DOS prompt solved the problem."

Sound like a hassle? Be advised: electronics CAD programs are inherently sophisticated things, and I've never seen one worth having that didn't take a big investment in time to learn. Don't get the idea three weeks before your project is due that you're going to find or buy and learn to use a PCB layout program and do your project drawings on it. You'll be sorry.

A somewhat newer version of DOS-based PADS can apparently be had: I've got no experience with it. Get these three files :
padstdx1.zip (750K)
padstdx2.zip (1105K)
padstdx3.zip (909K)

Also, there may be another older version, you could try these:

padswin1.zip
padswin2.zip
padswin3.zip

And, Mentor Graphics, who bought out PADS, looks like they put out a current (2006) Evaluation Version of PADS themselves.

AutoCAD PCB

AutoDesk's

AutoCAD

computer drafting program is found on a lot of University computers, including the Mechanical Engineering PC room machines. The E.E. Shop developed AutoCAD-PCB, (72K), a package of scripts, predefined blocks, and instruction for doing PCB design with AutoCAD. Some exerpts from the documentation that discuss general aspects of using software to make boards can be read here. 

More Software . . .

In addition, here are links to the home pages for

Even more E-CAD software links can be found through Printed Circuit Design Magazine's buyer's guide and directories, or through this index of CAD/CAE companies. And, Lazar has put up a very nice page of PCB design software, guides and resources on his Power Electronics Corner.

Also, it's worth checking our List of Printed Circuit Board Vendors since some of these may have software as well.