Wire wrap versus Strip board

Martin_H

I have been noodling with the idea of doing some demonstration digital circuits. Initially I plan to try simple things like reading and writing bytes to an SRAM, program a parallel EEPROM, try some address decoding. Fairly basic stuff, using the Propeller as the glue from the PC. My long game might be to build my own CPU board at some point in the future, but I figure learn the basics first.

Last week I was reading a web page (forget where now) by Garth Wilson that wire wrap is preferred to strip board for digital circuits. It can even be better than homemade PCB's because the tracks required for an address bus need to be finer than can be achievable with home made PCB's. Garth's a forum member and a capable guy so I'll take him at his word, but I've never done wire wrap and have always viewed it as really thorny to do and debug.

I'm far more comfortable with strip board because I can often layout a schematic to match the board which makes for easy point to point wiring. At what point would strip board become a problem versus wire wrap?

Heater.

It's a long time since I wire wrapped anything. A 6809 based computer with ROMs RAMs, parallel I/O, UARTs, timers, a cassette tape interface, the works!

Wire wrap is great stuff but I think you will find it's expensive. Those wire wrap sockets don't come cheap.

davejames

Martin_H wrote: »

(1)I'm far more comfortable with strip board because I can often layout a schematic to match the board which makes for easy point to point wiring. (2)At what point would strip board become a problem versus wire wrap?

(1) Then do that. For wirewrapping, you'll need a wrap tool, an unwrap tool (manual or powered), sockets, and wire. The tools last forever though.

(2) Ease of construction, ease of changes, reuse of components.

Depending on the brand of sockets, prices will vary. Wire-wrapping supplies are still pleantiful.

For straight-up digital circuits, wire-wrap is primo. Even when analog gets mixed in, wire-wrap can still be used.

RickB

To help with stripboard layout,
http://www.heyrick.co.uk/software/verodes/index.html

An alternative to wire wrapping with a home made wiring pen using polyurethane enameled copper wire with low melting point insulation.
http://elm-chan.org/docs/wire/wiring_e.html

Rick

Martin_H

RickB wrote: »

To help with stripboard layout,
http://www.heyrick.co.uk/software/verodes/index.html

Thanks. That stripboard software looks handy. The enameled copper wire looks impressive, but beyond my eyesight and manual dexterity.

KMyers

Not wishing to hijack this thread I waited until activity slowed. My question is does anyone know where I can locate a good wire wrap pen that holds a spool of wire on the top of it?

Radio Shack used to sell them but not now. In my old S100 days I would use this to make add ons etc even a sudo EEPROM. Unfortunately after several moves it got lost. Would like to do small boards for the prop. Any info will be appreciated!

Thanks

Tapperman

KMyers wrote: »

does anyone know where I can locate a good wire wrap pen that holds a spool of wire on the top of it?

Yeah, I have one of the old Radio Shack ones ... Not around anymore though. I did find this however:

http://www.digikey.com/videos/en/v/HW-UW-Hand-Tools/2434428801001

... Tim

Duane C. Johnson

Hi Ken;

KMyers wrote: »

Not wishing to hijack this thread I waited until activity slowed. My question is does anyone know where I can locate a good wire wrap pen that holds a spool of wire on the top of it?

You might be thinking about the Slit-N-Wrap tool by Vector.
Or this .pdf link
Supplied by Mouser. Well they don't actually have them at an exorbitant price of more than $200. Wow!!!

Duane J

KMyers

Thanks guys for info!
@Tappermanbut have one similiar but with one good hand its hard to use!

@Duane thats what I would like but too pricey..

Thanks guys.......

brucee

I'd say stick strip board for simple experimenting. Wirewrap with a hand tool takes a little practice and is prone to flakey connections. Nothing like trying to figure out where a broken wire came from for fun

Actually these days, I'd jump into getting a PCB made, the prices are quite reasonable vs the time you'll spend. Note that I come from a background of long ago at HP where we wire-wrapped everything, problem is as speeds go up you were fighting the ground bounce, inductance and crosstalk of the wirewrap boards. But the alternative back then was PCBs that were hand taped and took months to get built and were very expensive. Those days are long gone thankfully. Some people like building the PCBs themselves, but for me I'd rather lay it out, send it out, than have lots of nasty chemicals sitting around (they do have shelf lives).

I'll hijack this thread a bit, and poll people on what PCB tools they use. I have to admit I still use an obsolete tool (TraxMaker with OrCAD for schematic capture), which I still use because the user interface is very easy to use, and fits into standard Windows style. I have tried KiCad, DIPtrace and Eagle, but keep going back to TM, but last time I looked was about this time last year.

frank freedman

The Vector was expensive in the '70s at $25 I think I may have paid for one. Its great advantage was a gas tight wrap once you got used to keeping the tension. Never quite trusted my connections all the time. I ended up going with a Gardner-Denver auto cut-strip-wrap with power handle for around $350 mid '80s. It eventually died on me. Last year I got a new power gun and still use the cut-strip-wrap bit with it. It was on ebay for $25.00 Had what looks like a 15' power cord. Just if you do a lot of connections and possible mods though make sure your wrap router plans for this. My old CP/M program Wiremaster would give a wrap list out from a hand input net list that would plan wrap connections such that the minimum number of wires would have to come off to make a modification. Oh, for 10 more hours a day for "me" time.....

KMyers

@brucee never liked the looks of a finished strip board. Thought the wirewrap looked more finished somehow. Wirewrapped a Z80 once. Drove me nuts and became bald troubleshooting it. Ended up soldering it in the end. As far as a pcb I have made several. I have used Diptrace and Express PCB.

@Frank I agree but this is now just play for me to kill time. Might have to get used to the little ones!

Thanks Guys!