Q's for eagle and combining core and sid

Design Concepts
1

Ok, I am trying to combine the core and sid to one board, with the eventual goal of combining 4 cores and 4 sids to one board.

As I try I realize this may not happen…

first an eagle question, what is the way to create a library from an existing board? ( I want to make sure i use the same footprints as in Smash TV’s boards, so I can use the same orderlist, and spares from other orders.) I Think I need a ULP or script ore something.

Second eagle question, How the heck do you copy and paste in the library editor? I wanted to make a device for the SID chip and tried to copy the dil28 package as per instructions in the tutorial, to no avail… I wabnt to make the symbol and use it in the schematic, so i cna use forward back annotation, and so it will look pretty and be labled nicely like everything else. Maybe someone has done this already and wants to share the file?

Now, the stuff that might really stop me.

first, grounding: Do i need to seperate analog and digital ground? I mean everything I know says i should, but the only analog things on the sid are audio in/out right, and are not seperated on the sid layouts.(or are they?) I am prepared to use sockets with inbuilt bypass capacitors if neccesary to help against any digital noise.

Next, do I really need to use the voltage regulators on the sid boards? only one , or none? the thing will probably not be powered by the c64 psu in the end, because I will be running an aout and some other things too, and this will likely exceed its ratings, in addition to needing bipolar supply.

Finally , board space will be very tight . I am trying to do 2 cores and sids on the freeware version of eagle, and if i can get that accomplished , prototyped and working, get the nonprofit liscense, with twice the board area. what would be really bad to put too close near other components. I am figuring the audio section will get any breathing room i can give it, and the rest not so important? I have a basic idea of track clearances and widths and the like, but for noise or heat purposes???

just so you know the entire lcd section is being left out, there is no room on the case i plan to use for it anyway(it is an old rf amp chassis from some surplus telecom equiptment i purchased for 15 bucks at an auction) I may add a nokia display (i2c right) later. I will program and test the pics and sids on my existing hardware and transfer them to the final board, any problems then will be hardware related(bad soldering or hopefully not, poor layout).

That’s about it for now. thanks in advance for any useful advice, and sorry to bombard you all with so many Q’s I’ve been thinking about this all weekend.

2

Hi Arumblack,

I’m no eagle expert, therefore I will only answer to a subset of your questions:

first, grounding: Do i need to seperate analog and digital ground? I mean everything I know says i should, but the only analog things on the sid are audio in/out right, and are not seperated on the sid layouts.(or are they?) I am prepared to use sockets with inbuilt bypass capacitors if neccesary to help against any digital noise.

I think it’s only required that you don’t chain ground tracks of the analog domain with the digital domain and vise versa. Both domains should be grounded from a central point. Exceptions are allowed of course, e.g. if the digital part at the end of an analog section doesn’t consume much power. But it needs some experience (means: practice) to have a feeling for this. And you cannot get such a practice when you are not trying it out by yourself, no? :slight_smile:

If you want to be at the secure side, then try to seperate the grounds as much as possible.

Next, do I really need to use the voltage regulators on the sid boards? only one , or none? the thing will probably not be powered by the c64 psu in the end, because I will be running an aout and some other things too, and this will likely exceed its ratings, in addition to needing bipolar supply.

all SID modules can be powered from a single stabilized PSU w/o disadvantages. Of course, you need different regulators if you are mixing 6581 and 8580

Finally , board space will be very tight . I am trying to do 2 cores and sids on the freeware version of eagle, and if i can get that accomplished , prototyped and working, get the nonprofit liscense, with twice the board area. what would be really bad to put too close near other components. I am figuring the audio section will get any breathing room i can give it, and the rest not so important? I have a basic idea of track clearances and widths and the like, but for noise or heat purposes???

Maybe somebody with more layout experiences can give some useful tips?

Best Regards, Thorsten.

3

Ahh very good. I plan to use all 8580’s.

I think I found the ulp’s  I need for generating the libraries. I will try them out tommorow and see for sure.

I will try  to keep the grounds as seperate as possible, as I mentioned before, this should be fairly easy, due to there not being much analog circuitry anyway. Only thing that bothers me is the sid, it has only one ground pin but is both analog (filters) and digital (everything else right?) I am thinking though, that i may connect it to analog ground. It does not operate at the high frequency of the pic( but 1MhHz is still high, compared to audio)

of course it is all one ground in the end…

well, prototype prototype…

Thanks for the advice,

4

I made Library for the SID in eagle. If anyone want’s it let me know.

New question, but first a suggestion…maybe thre should be a sction of the forum for eagle, or any other, layout software questions.

Now the question… I exported a design as an image, but the holes in the pads have traces through them. How do i make the program make real holes? Iwill be making the boards myself either with tonertransfer or transperency for presensitized boards, so this is important…

Maybe I am just dumb…

I am getting along with eagle much better now though, but I can’t help but wonder why they chose to implement some things as they did.

Thanks in advance!

5

I think I may use some SMD’s to save board space. I think most people could solder SMD resistors and caps ok. They would be on the copper side of the board so maybe it will save some space. If nothing else they are smaller than their through-hole counterparts. I wonder, can I route traces underneath them? I don’t see why not. I will try to play around with this some next week, hopefully I can find the time.

6

INow the question… I exported a design as an image, but the holes in the pads have traces through them. How do i make the program make real holes? Iwill be making the boards myself either with tonertransfer or transperency for presensitized boards, so this is important…

Maybe I am just dumb…

No not dumb, these things are not obvious…

The best way is to use the cam processor to kick out an EPS file, and use any graphic software you have that will properly open (or import) an EPS for printing. 

To generate the EPS file:

Select File:Cam Processor

Then under Output set Device=EPS, Scale=1, and your chosen path and output filename (you must set the path!).

Under “Style” de-select Fill pads,

Activate layers 16 and 17, deactivate all other layers in the list on the right,

and finally select the “Process Job” button at the bottom of the window.

Dismiss the “Pads and vias should be active” error with OK, and you have a 1:1 EPS.

You might already have graphics software that will import and print an EPS, if not Ghostscript is a great free package available for all platforms.

I’m on a mac and just open them in preview, back in OS9 I used pagemaker and acrobat to pass them on to the printer.

Sorry I missed this when you first posted it…

Best

Smash

7

… with the eventual goal of combining 4 cores and 4 sids to one board.

Will it still be possible with your layout to build and power one Core+SID at a time, or will you need to build all four sets at one time?

I am very interested in hearing more if you manage to finish this design.  Have you spoken to either of the two board sellers (SmashTV and ..?) about stocking this board if you get it finished?

Even the 2x board you mention would be pretty cool.

8

Thanks  Smash, I’ll give it a try.

@ dr.Bunsen. Yes it should be possible to build one pair at a time. at this rate it may be a while umtil I’m even ready to prototype the board. I try to work on it when I can. I think I could finnish easily with a two sided board, but I am trying to stay on one side for now, so ppl can make thier own boards. If someone wanted to stock the board that would be fine by me, but I would want to do much testing first.

thanks all.