I use and like the autorouter. Perhaps none of my designs have very many signals that would be considered critical by today's standards :-). I have use the "signal class" feature to expand power traces, change spacing, etc. I have also done things like route power signals in a separate pass, etc. You can always hand-draw the critical stuff before turning the autorouter loose on the rest. In addition to the "more open" nature vs pcb123, I wanted to mention that the Freeware Eagle version will print schematics and layout, and even generate Gerber files for big boards. You just can't edit them. (It works a little like the "viewers" for various expensive Office products :-).) That means that while it cost me $1200 to do the TC08 backplane, I could share it with any of you, and you could get a board made, without shelling out for a license. Vince

der> That sounds attractive - but what are these .SCH and .BRD files? der> Is there any documentation on the format? I don't mind doing der> board layout and such myself, but I have to know what I need to der> generate. (No, running the software in question is not an der> option, if for no other reason than its being, I gather, der> closed-source.) I doubt the Eagle file formats are documented. But I assume Gerber files are, and those are the industry-standard format for board designs. The nice thing about BRD files from Eagle is that a lot of details you have to do explicitly in Gerber files, like gaps between power/ground planes and non-power/ground vias, or spacing for soldermask and the like, are handled automatically in BRD file format when you use Eagle. So if you have that program, a BRD file is a simpler way to feed the design to a PCB shop. But a Gerber file should always work. Are you thinking about creating an open source PCB CAD tool? paul

The standard you are looking for is named EIA-247 and is found at global.ihs.com to the hefty price of USD 78.00. It's somewhat hard to find the standard by using Google or something, but trying out "gerber file format" and "RS-274-D" gave enough leads to start a manual hunt at the standards institutes. Things to look out for: EIA-274-D The TIA/EIA standard ISO 6983 The ISO version (same thing in an ISO wrapper) Looking at the EIA home page (http://www.eia.org) is just depressing. A huge amount of gaudy pictures and policy statements and hard to find facts. Go directly to http://global.ihs.com for a "legal, paid for" copy. At the top left corner of the home page is a search thingamabob. Enter "EIA-247" in the "document number" field and hit the red "SEARCH" button, and off you go. I am sorry, but I have no clue about what all this look like in Lynx :) Perhaps some creative backup of the document somewhere can yield a lower price tag. Not that I recommend it, illegal as it may be and all that... ;-) Good hunt. /Ulf A. ------ der Mouse wrote ------

der Mouse wrote: (you may well find that in the end, there were/are actually good reasons for why things "have always been done that way" :-) You didn't ask, but if I was you, I'd do this: - grab a copy of the free eagle - fit your first design into the tiny dimensions the free version allows (and 2 layers). - capture the schematic and then do the layout by hand. you'll find you spend about 90% of your time creating library entries for parts and/or searching the existing libraries for parts which match. This means you'll end up with a .pdf file for *every* part and you'll know the footprint of each part very well. (this part is worth a lot of time - except for shorting power and ground, parts that don't fit on their pads/holes is the most common screwup imho). - use the design rule checking in eagle. it's reasonable (my opinion); don't stop until it's happy. - spend some time on the web googling for things like "pcb design rules" and "design for manufacturability". find sites which talk about proper trace widths, proper multilayer stackups (i.e. where power and ground layer(s) should be), how vias affect signals, etc... you could spend a lifetime on via's alone. I personally love the 3d pictures of signal returns when vias are used for high frequency signals on 8 layer boards :-) - go to www.pcbexpress.com; they have instructions on how to get eagle to spit out gerber files they can use. they can also take the .brd files wholesale. I find their service very reliable and their customer support great. (I use other houses also, but I like pcbexpress - they have been good to me). Their prices are reasonable for quick turn (my opinion). - spend some time looking at the gerbers before you send them off. - plot your files and send them off the pcbexpress. say a short prayer. wait for the UPS person to show up. I would start with a simple 2 layer board. Once that works, try a simple 4 layer board. I would do multiple 4 layers before I went to 6 and 8. Plus, you'll need the commercial version to do that. -brad

--- Brad Parker <brad(a)heeltoe.com> wrote: I found this to be the case too, creating libraires and getting around the weird quirks some of the CAD programs have takes LOTS of time. Sometimes I just bypass capturing the schematic (I draw it by hand on a piece of paper) and then do the layout directly using a CAD program. To do this you must become very familar with each chips pinout, but this knowledge is good as it makes it very easy to debug when you get the actual board. This method is sort of an hybrid between the pre CAD layout days and the modern full CAD method used today. Now if I have a cheap, quirk-free CAD program with all the library parts I needed I wouldn't do this, but for now its the quickest method for me. __________________________________ Do you Yahoo!? Yahoo! Tax Center - File online by April 15th http://taxes.yahoo.com/filing.html

I think this is one of the things that makes or breaks the usability of CAD software. I was able to design library parts for a number of Gxxx, Mxxx, and Wxxx DEC modules (needed for the TC08 dectape controller) in just a little over a day with the Eagle CAD software. These parts need very elaborate symbol views (essentially logic diagrams, needed to make the schematics that use them readable). Vince

DEC day views I can send it to you if you like; the library itself is not too large (but the TC08 is hundreds of Kbytes). Basically, there are two packages -- a one high 36 pin socket, and a two high (2x36 pins) socket. The modules have a symbolic view, usually a gate or group of gates, and the parts (modules) bind the pads on the socket to the logical pins, for as many gates (or groups of gates) as the module implements. The board fab wants about $450 for the first one, and about $90 for each additional. It is a big board, right at the limit of the size the fab will do (4 layer board, 18" x 14"). Whether it turned out to be Posibus or Negibus would depend on whether you populated the backplane with M623s or M633s, etc. (As far as I can tell, there is no wiring difference in the backplane itself.) I have also been slowly puttering away at replicas of the modules themselves, but don't have many of those done yet. The main problem I have is the steep cost of a single board, which prevents me from ordering one until I am darn sure it is right. I have been unable to find a TC08 wire list to check my netlist against, so it would come down to ordering a board, installing connectors, modules, etc. and testing the result. The chances of it working the first time are none too good, and the PCB is not easily repaired/patched (half the wiring is buried inside the board, and half the rest is under the connectors). Of course, once it was debugged, it would be much easier to build TC08s :-). If you have a TC08 to debug, the readable schematics and virtual backplane ("show xsta") would help you with your debugging. (I don't have one, hence the project :-).) If I was pretty sure the wiring matched DEC's, I'd risk the money to build one and see how it went. Until then the project is kinda on hold. Vince

steve> --- Paul Koning <pkoning(a)equallogic.com> wrote: steve> That wasn't my experience with Eagle, I tried the demo for a steve> few days and wasn't able to penetrate thru the user interface steve> to do even the simpliest of things. Its interface seemed steve> completely counter-intuitive as it doesn't adhere to typical steve> windoze interface standards which unfortunately have been hard steve> wired into my brain( eagle maybe a DOS port?). It certainly is a DOS port; the version I have (2.6) is straight DOS, straight command line. Those commands still work, and the manual may emphasize those, I'm not sure. There are also buttons. And yes, some other aspects are odd because they go back to the DOS code when there wasn't a windows graphics UI convention to adhere to. Things like what happens when you right-click during drawing, or the selection mechanism. It isn't bad, just different. Have you tried the tutorial? (I haven't but I remember it's there on the website.) paul

You left out - find a scratch x86 box - pay exorbitant rates for an OS Eagle will run under - assuming the implication I saw on the list that it's Windows-only is correct. And that's all assuming I'd be willing to trust something closed-source in the first place. That's why I was asking about file format documentation, so that I can generate the files myself, by hand if need be, if I can't find anything I can stand to do them myself. I also may see if I can lay it out in a way not too unsuited to a single-sided PCB and then try to do it myself, according to laser printer + transparencies + copper-clad board + photoresist + etchant + light + drill = PCB. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse(a)rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

der Mouse wrote: eagle runs under linux (as well as windos). runs well under X. take a look at the scripting language. I don't think there is *anything* you can't get at with it. you have access to the full internal database near as I can tell (which is more than I've seen with any other cad package) to be honest, these days, I think using an outside service for a 2 layer board is *much* easier and no more expensive (when you add up everything). (I've done single side boards from scratch, fish tank bubbler and all. never again.) -brad

It's also a lot slower (you can etch and drill a PCB in an afternoon -- I've done it, whereas it'll take about a week for the PCB to be sent back to you by post (at least if your snail-mail is anything like ours). When you're prototyping, modifying, trying things as you go, it rapidly becomes impossible if you have to wait a week for every new version of the PCB! -tony

Tony> It's also a lot slower (you can etch and drill a PCB in an Tony> afternoon... Certainly, if it's all through-hole stuff with no pin pitch smaller than 0.1 inch or so. I've done that too. It won't work for 120 lead surface mount ASICs, though, nor for 0603 size SMD discretes. paul