test please delete

[zeitghost]

I seem to have sent the congregation to sleep with my PCB design guide

We could have FORTRAN IV programming for beginners next

[TheBigYinJames]

Originally Posted by zeitghost

I seem to have sent the congregation to sleep with my PCB design guide

I used a program called SPICE, this was mid 80s. Apart from that I have very little recall of my PCB adventures.

[NickFitz]

Originally Posted by RichardCranium

dConstruct 2008. That'll be it then.

I'll stop there. There's hundreds of the damn things in Brighton in September.

I like the fact that this page is in Google's index as although it says "Page Not Found - error 404", it actually returns an HTTP 200 OK response code

UPDATE: and it's got an HTML 2.0 document type declaration

[kali]

Originally Posted by zeitghost

How much do you charge ?

You really wouldn't want too - maybe 15 years ago...

[zeitghost]

Spice is still around, except that these days it's got a flashy windoze front end so it doesn't frighten the punters quite as much...

I have a copy of NI Multisim that is basically a spice simulator.

It comes with its very own pcb design suite too, but I haven't used that yet.

I very rarely use simulators, I, being old school, build stuff to see if it works... I love the smell of hot solder & flux <cough, wheeze, spit>

[zeitghost]

Ok.



Catch you all later...

[zeitghost]

Originally Posted by kali

You really wouldn't want too - maybe 15 years ago...

You do realise I'm 54...

[TheBigYinJames]

Originally Posted by NickFitz

I like the fact that this page is in Google's index as although it says "Page Not Found - error 404", it actually returns an HTTP 200 OK response code

They'll be catching the 404 behind the scenes and redirecting. On ClientCoSite we use this very mechanism to produce resized car images on demand... you call the image with the size in the url e.g. /images/300x200/fordfiesta.jpg and when the server catches the 404, we redirect to a script which examines the url, creates the correct sized image on the fly from a large reference image, sticks it in the cache, and then redirects to that image.

[RichardCranium]

Originally Posted by zeitghost

16 layers is nothing really... that's the limitation on this yonks old version of CadStar I'm using... some packages have unlimited numbers of layers...

If you consider a ball grid array, where the balls can be 10 thou apart, it becomes difficult to get the connectivity without more than 2 layers.

Plus, as I said, two (or more) layers are used for power planes... using a layer as a power plane reduces the impedance of the power rails & reduces the amount of tulipe that can emmanate from the board... relatively more important these days... it can make a significant difference to the pass/fail EMI check of a design.

I don't think you could successfully design something like a mobile phone with a two layer pcb any more.

You certainly can't design a card to plug into a pc with two layers anymore... just to get the PCI interface working takes at least 3, and probably 4 layers.

In the case of PCI it's the signal timing on the interface that gets interesting... the design guide stresses the need to get the bus tracks all of equal length to reduce timing skew. Which ain't easy with a square surface mount chip. You also need the power planes in the board to define the impedance of the traces... it gets quite complex really.

Gosh. Things do move on.

That all sounds too hard now.

[RichardCranium]

Originally Posted by zeitghost

Almost time to bugger off to catch my train...

Bye. Thank you for the lecture.

Wavey wave.