Wire Wrapping: Discrete Components

[Johnny Starr]

I am going to give WW a go on my 6502 project. I've read Garth Wilson's detailed WW Q/A but, I didn't see much about discrete components.

I know you can get IC WW sockets (which are more expensive than I would like), but say I have just a few resistors and caps; do I need to solder them to some sort of post?

Also:
I saw that jameco.com has 100ft rolls of the Kynar wire. This seems like lot of wire for what I'm going to be doing. Does anyone know of another source where I could get say, a bundle of different colors at 20ft lengths?

I don't mean to be picky. But, to do wire wrapping its going to cost more for the tool and materials than the chips and parts of the actual computer.

Of course, I love the idea of WW compared to breadboarding. I'm not fond of soldering and the process of WW seems cathartic.

[rwiker]

In the past, I've simply used DIL sockets. I'm not sure whether this is a good idea; it is quite possible that there will be problems making good contact - immediately, or a few years on.

[GARTHWILSON]

The two little pictures about 1/4 of the way down the wire-wrap page are the main ways to add discrete components in wire-wrapped circuits.  If you instead put the leads of the components down through the holes and wire-wrap them, you need to solder them, because either their leads are round and won't bite into the wire at all to make the chemical weld, or, even if they're square or rectangular, they're not the right size for the tool to achieve that quality chemical weld.  Another thing you have to be careful of is that component leads are not nearly as stiff as WW pins, and they easily bend over to touch something they shouldn't, and that is made worse if the prototyping board doesn't have pads to solder the components' leads to to keep them from rocking.

Wire-wrap is kind of expensive, but I figure that it's not bad when you count your time.  The cost goes way up with WW PLCC sockets, but is still worth it in some cases.

[Johnny Starr]

Ahh ok, I guess I did miss that part.

I noticed that you have some sort of wire mask on the bottom in this pic:

Is that just like a label you printed out?

[GARTHWILSON]

They are commercially available labels like the one shown for 20-pin DIPs at http://www.jameco.com/webapp/wcs/stores ... 1_38586_-1.

6502.org wrote:

Image no longer available: http://www.jameco.com/Jameco/Products/P ... /38586.jpg

I see Jameco has the Vector WW pins I showed, at http://www.jameco.com/webapp/wcs/stores ... 1_34155_-1, $10 for 100 pins.

[nyef]

Should we presume that, if you don't care to spend money on the labels, or to wait for them to be delivered, printing out your own labels (or writing them by hand) is still a viable alternative?

[Johnny Starr]

I think the advantage to printing labels is you can have more relevant labels. A0 - A15 would be more helpful than pin: 20 - 36 or what have you. I also couldn't find any 40 pin commercial labels on there.

I did find this: http://www.jameco.com/webapp/wcs/stores ... &CID=MERCH

Which cracks me up because I paid a dollar more for the CPU. (shrug) Its not that expensive and I'm all for learning another dying art.

[GARTHWILSON]

Screw-machine sockets, even non-WW, are quite expensive.  I can't imagine there's any need for a hobbyist to spend $5 for a 40-pin DIP socket, but maybe I'm just thinking of when I bought my own stock years ago.  I guess they're losing the economy of scale now that WW is getting used very little in industry.

The labels are an unnecessary but convenient small luxury for saving a little time counting pin numbers.

Jameco is a very hobbyist-oriented distributor.  A couple of much bigger ones that are more industry-oriented but that will still sell to hobbyists are Mouser and Digi-Key whose catalogs were Jameco-sized 25 years ago but now have thousands of pages, closing in on three inches thick, of smaller print, too—and almost all of those parts are in stock!!  (Darn—now that I said that, I see Digi-Key's $1.85 40-pin WW socket is out of stock!)

[BigDumbDinosaur]

Johnny Starr wrote:

I saw that jameco.com has 100ft rolls of the Kynar wire. This seems like lot of wire for what I'm going to be doing. Does anyone know of another source where I could get say, a bundle of different colors at 20ft lengths?

I looked at our inventory of wire-wrap wire and noted that the spools are all 100 feet. You might be surprised at how fast you can use up that wire. Although I don't prototype much in wire-wrap anymore, I recall that wire consumption could be quite brisk in a reasonably complicated circuit.

[clockpulse]

Yes, it's hard to find wire-wrap sockets anymore, when you do see them they are expensive, especially the gold plated. I used to buy the wire in various colors that were in pre-cut lengths and pre-stripped in packs of 500. I don't think you can find those easily anymore, if at all.

[GARTHWILSON]

clockpulse wrote:

I used to buy the wire in various colors that were in pre-cut lengths and pre-stripped in packs of 500. I don't think you can find those easily anymore, if at all.

That may be partly because of digital parts and their slew rates getting faster, requiring that the wires be as short and straight as possible for good circuit performance, something you can't get if they're pre-cut in lengths longer than each connection needs.  It was ok when we were dealing with 1-2MHz parts, but I definitely don't recommend it today.

[clockpulse]

GARTHWILSON wrote:

something you can't get if they're pre-cut in lengths longer than each connection needs. It was ok when we were dealing with 1-2MHz parts, but I definitely don't recommend it today.

I mostly use pre-cut for 1 to 3 inch connections, if the sockets are laid out correctly that's not really a problem. I have a 65C816 running at 10mhz with almost all of the connections using the pre-cut wires. However, you do need a good stock of different lengths. I stocked up pretty good in the mid 80's.

[Johnny Starr]

clockpulse wrote:

I stocked up pretty good in the mid 80's.

Yeah, being born in '83, I missed out on the golden age of home computing. I think a lot of people my age are spoiled with tablets and phones; even those technically inclined. Most of my friends think I'm crazy for "wasting" my time with "that old stuff". Honestly, I would rather spend $150 on wire wrap and other parts than on the latest trends. I have fun for years with this stuff while they run the treadmill of trying to have the latest generation [blank].

[ElEctric_EyE]

Johnny Starr wrote:

Yeah, being born in '83, I missed out on the golden age of home computing. I think a lot of people my age are spoiled with tablets and phones; even those technically inclined. Most of my friends think I'm crazy for "wasting" my time with "that old stuff". Honestly, I would rather spend $150 on wire wrap and other parts than on the latest trends. I have fun for years with this stuff while they run the treadmill of trying to have the latest generation [blank].

That's great, I love to hear that kind of thing!
I've had a 3.3V WDC65C02 system running close to 20MHz with wire-wrap so for a simple SBC wire-wrap is great.

Did you purchase the WW gun yet?

[Johnny Starr]

ElEctric_EyE wrote:

Did you purchase the WW gun yet?

No, I haven't made any purchases just yet. Are you recommending the gun vs. the highly esteemed Ok Industries hand tool?

At this point, I'm probably going to build my project on breadboards and purchase the WW stuff later. This way I can do my minimal SBC and do the WW when I'm ready to add a UART and or VIA.

I'm still shopping around for cheaper prices though.