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Are Wire Wrap Products Dying Out?
tie_guy_matt asks: "I was in our stockroom at work trying to get connectors so I could reproduce a circuit board that I broke (oops!) I wanted to get a 20-pin connector that I could use on a wirewrap board. The guy in charge of the stockroom said that they no longer make that type of connector for wire wrap boards. Companies are starting to produce more and more surface mount chips and less and less DIP chips. Ever try to solder a sufrace mount chip onto a homemade circiut board? There is only one company left that makes wire wrap stuff: OK Industries. If this company goes under we may no longer be able to make home made Z80 computers from parts we bought from Digikey. Are hobbiest starting to have trouble finding the parts they need? Will very small companies now have to spend a lot more money to make prototypes? Is this yet another example of how big companies are squashing the little guy?"
Is this yet another example of how big companies are squashing the little guy?
Why must this be the result of malice?
Most components sold and used will be destined for production circuit boards. Thus, wire-wrap compatible components won't make much money, but will still require the infrastructure needed to support the different packaging type.
Add to this the fact that many small companies (including the one a hundred feet from me) send their schematics out to third-party board-makers for prototyping, and the wiretap market looks pretty small.
Why would you fault companies for dropping unprofitable product lines?
For the record, I haven't had any trouble finding DIP components in my area, so this question is academic for me.
Perhaps you just need a few tips on wire wrapping
Certainly using FPGA's reduce the ammount of wiring but they don't eliminte it. You still have to connect the FPGA to swtiches, analog parts, edge connectors, etc.
A few years ago, I built a high speed serial board. I put everything I could on the FPGA becuase I didn't want to have to deal with the interconnect. But I needed to wirewrap connections to:
1) Configuration PROM for the FPGA
2) Clock
3) Tranceiver chip
4) External SRAM
5) Edge connector
6) DB9 for the serial cable
7) 8 pin header for in circuit reprogramming of the FPGA.
8) A debug header so I could reliably connect the logic analyzer to figure out what the board wasn't working.
Two comments:
1) The word is "hobbyist", not "hobbiest" - this may be on of the most consistently misspelled words on slashdot. Sorry for the gripe, but I just couldn't take it any more...
2) There's no grand conspiracy, and your enthusiasm for wire wrap tells me you haven't really done all that much with it. It's easy, but also fraught with problems, and pretty much useless with today's speedy hardware. Many of us have all too many war stories about hardware debugging from hell. An inordinate number of these stories involve wire wrapping...
I use wire wrap wire all the time, but I haven't actually used it for wire-wrapping in years.
"The future's good and the present is nothing to sneeze at." - Roblimo's last
I've noticed the trend of moving away from wire-wrap in the hobbiest arena, and the move toward SMD. It has been going on for some time, but where it is really evident is in the current scene of hacking NCs.
I run a web site (link off my main site, above) for hacking the Acer NT-150, and recently a few of our members managed to solder an SMD part in order to gain access to a "disabled" serial port (ie, the pads for the chip were there, and the socket holes were there, just those two parts were missing). It had a small number of pins (28?), and when mounting, tended to slide on the surface of the pads, because the top surface was curved. The members mentioned getting the corners tacked down, then going for the rest of the chip.
So far, three members of our group have been successful - one even managed it without any former SMD experience! I haven't got any SMT experience myself, but I am even tempted to try it out (the part is a MAX part, and can be gotten as a free sample).
I like wire wrap, but it is limited to certain designs. However, the majority of hobbiests don't tend to do high speed designs, so it hasn't been much of a problem. Anything higher, and going to a regular PCB, then to SMT designs - has tended to be the route...
Worldcom - Generation Duh!
Reason is the Path to God - Anon
As long as you are keeping the speed down (under 20 MHz or so) wire wrap works well, but as you go higher and higher in frequency, the added inductance and stubs of wire wrapping will kill you. Many of the newer parts are getting harder to find in DIP- especially as the pin count goes up. I don't know of any (modern) common part in a DIP package > 40 pins. On the other hand, 300-400 ball BGAs are getting common- imagine trying to wire wrap that! There is no real market in making a new quad XOR gate in DIP- that technology is mature- they won't really be able to improve on it, except possibly to make it faster, but a DIP package has leads, and leads have inductance, and inductance kills high frequencies, so by default, if you are improving the speed on an IC, you need to shrink it and go to SMT. They are also trying to cram more into a chip, but that implies a greater pin count- again, which pushes you to SMT.
But, as the person who posed the question implied, SMT is difficut for a hobbiest to work with. One alternative is to make your own PCBs, either by etching them at home, or go to some place like APCircuits where you can get prototype PCBs made pretty cheaply. And one hint- if you are doing SMT, get the solder mask, it will make your life very much easier.
I still wire wrap when I need to- and Digi-Key has had most of what I've needed, though the little pins to mount discrete components are outrageously expensive. (In particular, the T68A bifurcated pins, with room for 3 levels of wrap, at $92.25/1000.)
1. Pack up the Gerber file and send it on its way to a prototype shop, and they send you back the boards. If you can't afford the three hundred (seen it as low as eighty) bucks then laser print onto mylar, press onto FRP (or whatever) with hot iron, and etch.
2. Assuming that the proto house won't put the chips on for an extra fifty bucks, glue the suckers down, solder wash, and drop in the convection oven.
3. Take coffee break, or go back to Spice.
4. Remove cold board from oven and do other side if required. Clean off connectors and test.
As one who still has to put up with wire wrap on an almost weekly basis, I can tell you that I never want to see one of those cheezy little OK wirewrap guns again in my life. Or big bulky cards, little wire tails shorting pins when you least expect it, connections sliding off due to worn bits, oxidised connections, and once somebody's made about three layers worth of changes, trying to figure out where the other end of the damn wire goes, because they didn't write it down.
Wire wrap. Bah. It made me the man I am today...
*whup* "Get along, little electrons. Heeyah!"
SMD is not all that difficult to BreadBoard if you use surfboards to solder the SMD onto first. Surfboards are small PCB the size of DIP packages with pads for the SMD, and pins where the DIP would have them. I have soldered even 25 mil spaced , 150 pin SMD packages by just using a small soldering iron at home provided you do have a proper surf board or PCB. SMDs that are 50 mil spaced are not a lot more difficult to solder that regular DIPS. SMDs also have tha advantage of being very-very easy desolder of a discarded circuit board with a heat gun or something. DIPS would be a lot more difficult to desolder in this case. So, it is really not all that difficult to used SMD parts