I don't see what's so special--LPKF has been doing this for years. Even to the level of plated-through vias. It's just time-consuming and expensive. Far easier to send your artwork out and get plated connections and really good solder resist.
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I don't see what's so special--LPKF has been doing this for years. Even to the level of plated-through vias. It's just time-consuming and expensive. Far easier to send your artwork out and get plated connections and really good solder resist.
The wire wrap tool and kynar wire assortment, that this thread inspired me to finally get around to buying, arrived today. Now to salvage all those old wire wrap boards. There are probably 300 sockets among all of them. Hopefully my desoldering gun is deep enough to get pin 1 desoldered from the boards easily.
This is all for prototyping, for me, though. Wire wrap sockets are too expensive to use up on permanent projects!
I do have an electric wire wrap tool coming too, though. Cheap and used of course (I am so tight that my toes curl when I blink). Although I am only 42, many years of piano and Model Ms has left me with enough carpal tunnel problems to make spinning a tool like that pretty painful after not too much time.... :/
-- Lee
If you get super-bored, try muh crappy YouTube channel: Old Computer Fun!
Looking to Buy/Trade For (non-working is fine): Tandy 1000 EX/HX power supply, Mac IIci hard drive sled and one bottom rubber foot, Multisync VGA CRTs, Decent NuBus video card, PC-era Tandy stuff, Weird Old Unix Stuff, Aesthetic Old Serial Terminals (HP and Data General in particular)
For removing pins, I created a tool on my lathe from brass rod that lets me push those pins out easily without bending or breaking them. Then it's just a matter of supporting the board over a pan and going tap-tap-tap with the tool. Works very fast. I don't bother desoldering any of the soldered in pins. I can take a photo if you'd like. Basically, start with a few inches of 1/4" brass rod, turn the last inch or so down to about 0.1" and bore a hole through the center with a #58 (IIRC) drill deep enough so that the WW pin doesn't bottom out in it. I think I made one of these for Andrew a few years ago.
Last edited by Chuck(G); November 21st, 2020 at 12:13 PM.
-- Lee
If you get super-bored, try muh crappy YouTube channel: Old Computer Fun!
Looking to Buy/Trade For (non-working is fine): Tandy 1000 EX/HX power supply, Mac IIci hard drive sled and one bottom rubber foot, Multisync VGA CRTs, Decent NuBus video card, PC-era Tandy stuff, Weird Old Unix Stuff, Aesthetic Old Serial Terminals (HP and Data General in particular)
A Chineseium mini lathe might save a bit of cash (I haven't checked Alienexpress yet), but it usually requires more than a bit of tweaking. The Harbor Freight ones have gotten stupid expensive--you used to be able to pick one up for under $400. The alternative is to shop estate and garage sales and see what turns up (pun intended).
I saw a couple of photos that reminded me of how both wire wrapping and some styles of point to point soldering are really both not good (in my humble opinion).
In the case of wire wrap, although the wiring is more orderly, the long square section IC socket pins poke well away from the pcb surface and are begging to be shorted out on the nearest metallic object, and you cannot stack boards closely, like you might need to in an S-100 computer for example.
In the case of point to point wiring, look at the total mess of wires which obscure the view of the IC socket pins and grossly thicken the solder side of the pcb.
Finally the method I use on the same photo, where care is taken with the routing of the wires and they are restrained to the pcb surface with small hoops of insulated single core wire. In addition all the solder points remain visible for inspection and all the flux is cleaned away after its done. I would recommend if you are going to hand wire a pcb, it is done this way, unless you want the mess shown on those other two cards.
The pcb engraver is impressive.
Silicon Chip Magazine are about to publish (next month) a technique using simple jpeg image files and a laser engraver to make economical pcbs.
For my own home made pcb's I use a laser printed film, that irons onto the pcb, and a ferric chloride etc.
Yeah, I don't want to use WW for anything but prototyping, unless I make a WW CP/M computer just for fun (it would of course have cheezy modern gaming PC accent lighting, but to highlight the mess of wires instead, and I would have to figure out some way to incorporate some vacuum tubes). :3
I mainly want to use it for prototyping expansion cards. All those bus connections are too much to keep orderly on breadboard; once one wire pulls out somewhere you are wasting too much time tracking it down, and soldered stripboard is not so good for changing around easily. For the ISA boards at least, I'll be extending the bus out to a passive backplane out on the bench, using a short-ish piece of 64 conductor ribbon cable. The WW protoboard will be the only other thing plugged into the backplane, so I can get to it with probes easily and it won't be shorting out on anything. I 'spect I can do something similar for the Apple II, but I don't have the parts on-hand for that.
-- Lee
If you get super-bored, try muh crappy YouTube channel: Old Computer Fun!
Looking to Buy/Trade For (non-working is fine): Tandy 1000 EX/HX power supply, Mac IIci hard drive sled and one bottom rubber foot, Multisync VGA CRTs, Decent NuBus video card, PC-era Tandy stuff, Weird Old Unix Stuff, Aesthetic Old Serial Terminals (HP and Data General in particular)
Years ago a friend found some dozens of small miniature double triode tubes. So we got the idea to make them into flip flops and logic logic circuits to make a digital clock that had a low frequency timebase like a big tuning fork, so that not too many divider stages were required and then something like a light bulb or hot wire seven segment display. We never quite got around to making it though.
I dunno--I have 30+ year old WW designs that still work, so it's not a matter of reliability. One reason I use WW for one-off designs is that I don't have to go through the bother of working out PCB layout--and modifications are easily done.
There are/were some things that WW was specifically well-suited to. One that I can think of is ECL designs, where outputs are differential and so use twisted pair designs. Working that detail out with a PCB layout can be a nightmare. The other aspect is that even for slower signal clocks, the length of a wire can easily be controlled to avoid glitch conditions.
I made this over the holiday break. My PDP-8/E was available online until I upgraded the server to a modern low power machine that didn't have a parallel port. I bit banged the PC parallel port to control the PDP-8. This board goes on a beaglebone to allow the new machine to control the PDP-8. I still use wirewrap for simple one off boards like this so I don't have to wait for PCB. Have all the supplies around. Looks like it was at least 22 years ago when I made the original wirewrap interface boards. http://www.pdp8online.com/pdp8em/pic...ge.shtml?small. Still working with a friend on converting the java control interface to JavaScript since almost nobody has java enabled in browser anymore. PDP-8 will be back online when that's done. Its annoying the interface to my obsolete computer is obsolete so I have to redo it.
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