"Tim Williams" wrote in news:qh5v6l$10e$ snipped-for-privacy@dont-email.me:
Go to google images and pump "12 minute mandelbrot" into the search field. A bunch os computer hdw pics and fractals come up.
They used a 50 year old mainframe to make fractals and it was wire wrapped tech.
snipped-for-privacy@decadence.org wrote in news:qh98sn$fr3$ snipped-for-privacy@gioia.aioe.org:
Some nice, smart dude's blog.
snipped-for-privacy@decadence.org wrote in news:qh99ff$j4k$1 @gioia.aioe.org:
snip
Oh, and I noticed also that no one in the group even mentioned the death of Chris Kraft on the 22nd.
Oh that's right... everyone here thinks the space program is a waste.
It certainly can. Augat used to sell standardized panels with power on one side and ground on the other. Some had the corners connected and others used things that looked like 0.100" bobby pins, soldered around the WW socket pin to connect to the pour. They worked exceedingly well. I used them up to about 50MHz.
Which, of course is horrible for speed, which you were just complaining about.
There were 3-level pins, as well. Long strings are better, in any case.
IBM used WW for board backplanes, as well. Worked really well, though they were also printed and multi-layer.
100-ohms, with teflon wire, anyway. Not bad at all. The more random the wiring the better the impedance.
I prefer Teflon wire, though I've switched from #30 to #32 wire (because I can't find smaller). #30 wire is huge compared to 0402s and QFP leads, for instance.
Wire-wrap was pretty normal for the computer backplanes of the
1960's and 1970's. Often the regular bus lines were circuit board foils and the non-regular lines wire-wrapped on the connector pins.One of the larger computers of the era using the hybrid backplane as the Univac 1108.
At Memorex, late 60's, the disk controller backplane was wirewrapped by an outside firm. It didn't work.
All the unnamed nets were wired together.
I control impedances and terminations on a PCB. I can have a 50 ohm trace that splits into two 100 ohm traces. Wire-wrap can't do that.
Wire-wrap was expensive and barbaric, which is why hardly anyone uses it any more. It was sorta usable for breadboarding, back when we used DIP ic's in sockets. I don't miss any of that.
The really good thing nowadays is quick-turn, cheap multilayer PCBs for prototyping.
Ah, crosstalk as an impedance controlling technique.
The beldsol thermal-strip magnet wire is useful, sometimes.
It solders a lot better if you scrape away just a bit of the insulation first. It does allow daisy-chain connections with one piece of wire and no stripping.
This is particularly good stuff:
The enamel melts almost instantly. To solder it, you just pretend the enamel isn't even there. Soon enough it won't be.
-- john, KE5FX
Theres a ROHS exemption on thin wire, because without lead, the copper migrates into the solder. Just something to beware of.
Cheers
This is 40 ga. I find such thin wire breaks easily and won't carry much current.
I'd go for 28 ga. Much more robust.
I found out what "sold ER able" means
"soldERable"
Why do people do these things.
spelling checkers, also the vendor doesn't know the product.
Yup.
It does allow daisy-chain connections with one piece
Genuine Belden wire is horrifically overpriced, though--I get the same stuff very cheap on eBay.
RG-402 semirigid coax used to be fairly cheap too, but a decade or so back the price about tripled and has stayed high. Belden wants about $8 per foot!
Cheers
Phil Hobbs
About $4 per mile of wire. Not bad!
Cheers
Phil Hobbs
That's where I got my genuine Beldsol.
After 50 years and a few trillion dollars, I'd hope we'd have learned a few things.
Exactly the opposite. Random wiring reduced crosstalk (few/no parallel wires) and helped control impedance.
Phil Hobbs wrote in news:qheqlr$2dv$ snipped-for-privacy@dont-email.me:
Yeah, but they go to like 30GHz now too. What I mean is are they not a lot more reliable and better constructed now? (I know... not $8 a foot better)
A lot of the signal pipes on quantum computers are semirigid matched sma links.
Have something to add? Share your thoughts — no account required.
Ask the community — no account required