Article View: sci.electronics
Article #11097Re: Need advice on PCB packages for PC
From: gordon hlavenka
Date: Fri, 09 Oct 1992 05:27
Date: Fri, 09 Oct 1992 05:27
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5625 bytes
vnelson@ccu.umanitoba.ca (Gerald Vernon Nelson) writes:
>We use EE designer at our electronics design and manufacturing company
>in Winnipeg, Manitoba.
>...
>According to our resident expert, EE designer is considerably faster at
>redrawing than Autocad. The most complex board we have
>ever built using EE designer is about 800 parts, through hole and SMT.
>
>The package is fairly easy to use.
I use EE Designer myself. I have used EE 1, EE 2, and am currently
using EE 3. The package will run on any platform from a 4.77MHz XT
with a CGA up through 486/33 with Tseng 4000 VGA at 1024X768.
It is a DOS application, but it runs acceptably (albeit noticeably
slower) under Windows 3.0. There is support for through-hole and
surface mount, curved traces, multi-layer, and ground planes.
EE designer is ported from a Swedish product, and as such some of the
menu selections are a little weird ("Sure to plot this?") but usually
understandable. The documentation suffers from this also, so some of
my complaints may be the result of bad docs (I _try_ to read them)
rather than program limitations.
There are some glaring shortfalls. A schematic symbol is linked with
a layout symbol in a "DEV" file. DEV files run a few hundred bytes at
most, and there must be one for _each_ type of device used. This
really eats disk space for large libraries.
The BOM generator is useless. I cannot generate a BOM unless I
_first_ provide vendor information for the parts used in the design.
And then, all similar parts get grouped together (i.e. all 1/4 watt
resistors are one entry in the BOM.) To get a "proper" BOM I have to
create a separate DEV file for _each resistor value_. Oh yeah, and
each of those DEV files has to have a vendor info file associated with
it.
The DEV files describe the relationship between scematic symbols and
layout symbols. However, each schematic pin can only be connected to
one layout pin and vice versa. So a 74LS04 is easy, but you can't build
a 74LS374 as 8 separate schematic symbols without kludging to show the
common connections to the /CK and OE pins! Even a SIP resistor array
can't be built as separate resistors. What's strange is that this
worked in EE 1 and EE 2. It only broke starting with EE 3.
About that autoplace and autoroute. When you first move a design from
schematic to PCB, all the components are placed on top of each other.
Autoplace is useful only for spreading them out so that you can pick
them up individually. The autorouter does a nifty thing called "via
minimisation." Sure does. Unfortunately, it sometimes neglects to
reroute the traces, so you get open paths. I've had several boards
come back with via holes missing because they simply got tossed out by
the autorouter. On simple designs you can do everything manually, but
for the big stuff you have to trust the @#$%^&* software.
Also, routes which fail autorouting may be tagged in the design
database as "connected," so when you run a netlist test it passes and
when you eyeball the board you see a dozen pins you _know_ should be
connected to something but have no traces attached.
The NC Drill tape output defaults to putting wrong tool size
information in the tape header. You can produce beautiful Gerber
files, but you can't produce an aperture listing file to go with
them.
The menu system itself is non-obvious. Many actions (as you would
expect) require the user to answer yes/no questions. But sometimes
this is done by typing Y<enter> or N<enter>. Sometimes it's done by a
hotkey. B is yes, A is no. Sometimes H is yes, and G is no.
Sometimes it's other letters. The result is that you can't just roll
through the menus because you have to stop and read everything. Even
WordPerfect, with the world's nuttiest keystrokes, can be learned. EE
Designer cannot.
I have also used a product called HiWire. This is a GREAT schematic
program, but the layout features have not been there for me (yet). I
get each HiWire demo package as it comes out, but the PCB module just
isn't soup yet. I have an old version from 1986 or thereabouts, and I
love it. For schematics. It's actually faster than bar napkins!
EE Designer is a powerful program, but it earns a rating of (a la
Jerry Pournelle) "infuriatingly excellent" -- It Does Great Things,
but only after much travail. Reading back, I seem to be bashing EE
Designer pretty heavily. It _is_ a good program, but doggone it these
detail things drive me nuts! I don't regret the three grand it cost,
(I made that back on the first project I did with it) but there are
definitely major quirks.
I currently use HiWire to prepare proposals since I can have a
beautiful schematic in a matter of minutes to hours. Then I use EE
Designer to do the actual work. But if Wintek ever gets a real PCB
package integrated into HiWire, there will be an EE Designer package
for sale over here!
--
----------------------------------------------------
Gordon S. Hlavenka cgordon@vpnet.chi.il.us
Don't forget: Dave Barry/Joe Walsh in November!
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<1992Oct09.052757.1602@vpnet.chi.il.us>Path:
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Newsgroups: sci.electronics Path: arc1-ca.pugleaf.net!sparky!uunet!zaphod.mps.ohio-state.edu!rpi!newsserver.pixel.kodak.com!laidbak!tellab5!vpnet!cgordon From: cgordon@vpnet.chi.il.us (gordon hlavenka) Subject: Re: Need advice on PCB packages for PC Message-ID: <1992Oct09.052757.1602@vpnet.chi.il.us> Organization: Vpnet Public Access References: <1992Oct5.150357.17668@kakwa.ucs.ualberta.ca> <1992Oct7.024814.15955@ccu.umanitoba.ca> Date: Fri, 09 Oct 1992 05:27:57 GMT Lines: 97