Schematic and PCB software

[ChrisW]

I'd like to eventually move my 6502 computer from stripboard to PCB. Can anyone recommend any Windows software for inputting the schematic and turning it into a PCB layout?

[GARTHWILSON]

Some prototyping board houses like ExpressPCB in Santa Barbara, CA have their own free board lay-out CAD for Windows. In fact, this one requires you to use theirs only. Nightmaretony uses them, so he can tell you more.

[SimonJ5]

Chris,

Across our side of the pond there's an outfit I have looked at (but never used so the usual disclaimer) called PCB Pool (http://www.pcb-pool.com) who claim to be able to use Eagle layout. There's a freeware version of Eagle from CadSoft which is limited in the number of pins and the size of the board produced but it might be enough for you.

I haven't used PCB Pool nor Eagle in anger but I hope to soon.

Simon

[Ruud]

ChrisW wrote:

I'd like to eventually move my 6502 computer from stripboard to PCB. Can anyone recommend any Windows software for inputting the schematic and turning it into a PCB layout?

I advise Eagle <www.cadsoft.de>. If you need libraries and want to have a look at schematics using a 6502: http://www.baltissen.org/newhtm/schemas.htm

Have fun!

[ChrisW]

Thanks for the suggestions. I'll probably start by having a play with the free version of Eagle.

I've used EasyPC before at work. It seemed very good but I can't afford to buy a copy for myself.

Simon, another place I've stumbled upon through Google is PCB Train: http://www.pcbtrain.co.uk/

[fachat]

SimonJ5 wrote:

Chris,

Across our side of the pond there's an outfit I have looked at (but never used so the usual disclaimer) called PCB Pool (http://www.pcb-pool.com) who claim to be able to use Eagle layout. There's a freeware version of Eagle from CadSoft which is limited in the number of pins and the size of the board produced but it might be enough for you.

Well, I regularly use both (Eagle and pcb-pool) and it seems to work so far :-)

André

[adsouza]

Quote:

I'd like to eventually move my 6502 computer from stripboard to PCB. Can
anyone recommend any Windows software for inputting the schematic and
turning it into a PCB layout?

for schematics, i have tried OrCAD, ExpressSCH, and Eagle CAD. all 3
allow you to convert your schematics to PCB layout.

i like ExpressPCB since its small, fast, and easy to use. i like Eagle CAD
also; i use the free version.

i have used OrCAD in my first job (1989-1992). it used to be small and
great. now its huge and bulky and not that nice anymore.

since Eagle CAD is more popular and powerful, i think, its what i would
recommend. i used the Free version and it does not allow you to CUT
to make changes. i am sure that the paid version is better.

i hope that you find this information useful.

[GARTHWILSON]

Quote:

i have used OrCAD in my first job (1989-1992). it used to be small and great. now its huge and bulky and not that nice anymore.

I was using OrCad at that same time. Perhaps our applications were more complex and our expectations higher, but it was absolutely terrible-- more bugs than an ant hill. They kept sending us updates to fix the bugs, and each bug fix would come with two more bugs. Since we were the squeaky wheel, we got updates sometimes a couple of times a week, even two days in a row sometimes, as they frantically tried to take care of the problems. They sent out a newsletter telling about their great programmers being so productive and writing the new version at a rate of X lines of code per day, and I thought, "Ah-- there's the problem-- trying to measure progress by lines of code per day!!" It's always guaranteed to be a loser. They needed an entirely different approach and philosophy, and it probably wasn't going to happen as long as they used the same people. I imagine they probably had an absolute disaster of unmodular spaghetti code that was not well documented.

For the last 12 years I've been using Number One Systems' Easy-PC Pro. It was one-tenth the price of OrCad. It initially had a lot of bugs too, and with all of our wheel-squeaking, they took care of it. I like the software because it's a good, flexible tool for doing what I want to do, which is sometimes rather unorthodox. It just lets me do it instead of trying to second-guess me and telling me I can't do this or that or helping with something I don't want. Other CADs try to be too intelligent sometimes and as a result, stand in the way. I've done various things with this one that it wasn't even particularly made to do. After No. 1 Systems got virtually all the bugs out, they tried to make it more attractive my adding all kinds of modules to it for simulation, autorouting, and other things that were of no use to someone whose work was outside of what the programmers envisioned. I just keep using the old DOS version. I've mostly done extremely dense (40-60 parts per square inch across-the-board average, which supposedly is impossible) thru-hole analog and mixed-signal multilayer boards for our aircraft products with it, but last month I laid out a dense surface-mount board with it for the first time for something that will go on the deck of aircraft carriers. (Think, "RFI city!") The employer is quite pleased with it.

I always found starting with the schematic in CAD to be too limiting. Even with the schematic capture done, the PC board layout part of OrCad would sometimes direct the user to hook things up wrong, because of the bugs. As for the autorouter, take for example two pins next to each other on an IC that were supposed to be connected together (.100" apart), even with a clear shot from one to the other, sometimes OrCad would take off in exactly the wrong direction, wander all over the board, and then stop and say the connection can't be routed. There are things I don't like about any of the schematic CADs I've demo'ed or used (including Easy-PC Pro), things that mainly prevent the most straight-forward, clearest, neatest schematic; so I keep doing schematics by hand. My main complaint about the CADs is that they don't allow drawing large ICs like processors, LSI, etc. whatever way works best for the schematic. Instead of making just a schematic symbol and making you stick to it, it should let you draw the individual pins wherever is most suitable for where they need to get connected in the drawing.

Enough rambling.

[Nightmaretony]

Express PCB I liked, Darryl's SBC uses it, mine was based on it as well. The major 65C134 I also used it for. Been using PADS atr work, just got certified on it.

Insanely busy as always... will have to get my rear back in gear oi it all....

[RichCini]

ChrisW wrote:

I'd like to eventually move my 6502 computer from stripboard to PCB. Can anyone recommend any Windows software for inputting the schematic and turning it into a PCB layout?

Since I'm doing some SBC projects now, here's how I do it. I use Diptrace for the schematic capture. I find the software easy to use, particularly to create custom components and to place busses.

Diptrace comes with a PCB layout program with autorouter. The layout program is fine but the autorouter is not as efficient (in routing and speed) as it needs to be.

The schematic program can export netlists in several formats, but I use the Tango format. The board house I use is PCB123.com and their layout program is very good and the autorouter is decent for a free program. Further, it can import several netlist types including Protel and Tango.

So, I take the Tango netlists from Diptrace and import them into the PCB123 program and fix-up any footprint issues (different footprint and/or pin naming conventions). Some nets I route and size manually (like power busses) and do several rounds of autorouting and component placement changes until I get it the way I want.

I successfully routed a backplane for Daryl's SBC this way. I also have a completed design for a relay output board and I'm working on a speech board for the SBC.

Now, PCB123's prices for only two boards isn't the best ($100 for two 6"x3" double-sided boards) but if they get very reasonable at the Q10 level (about $20 each).