Who is Robyn ? My daughter's name is Robyn. On 10/11/2017 04:17 AM, Dave Daniel kc0wjn@... [Homebrew_PCBs] wrote: > > Robyn, > > For what it's worth, I have a pop-up canopy that we can use if needed. > It is 10' x 10' or 12' x 12'. I used to use it at the Lyons Outdoor > Games festival when I did the kayak scoring. > > Dave > > On 10/7/2017 3:45 AM, 'Tony Smith' ajsmith1968@... > [Homebrew_PCBs] wrote: >> >> Oh, I knew SLT meant the modules, I guess I could have been clearer. >> >> The idea of having vertical & horizontal traces on opposite sides of >> the board was an older idea, I thought they designed the modules to >> match. >> >> The boards themselves were just punched phenolic, some apparently >> were multi-layer (with ground & power), I don\u2019t know how that worked, >> you couldn\u2019t have vias everywhere. Not that they really needed it >> given the low speeds, maybe it made wiring easier. >> >> This was the original stuff: >> https://www.cs.auckland.ac.nz/historydisplays/FourthFloor/Packaging/PackagingImages/IBM1620Boards.jpg, >> same idea with the SLT modules: >> http://www.chipsetc.com/uploads/1/2/4/4/1244189/2744349_orig.jpg. I >> can\u2019t remember the magic words to find that PCB prototype stuff, >> someone re-invents it every so often. >> >> The multi-wire stuff you\u2019re describing sounds like a different >> process, maybe it came along later? Running wires like that was >> probably cheaper & faster than etching PCBs, a bit like wire-wrapping >> I guess. >> >> Tony >> >> *From:*Homebrew_PCBs@yahoogroups.com >> [mailto:Homebrew_PCBs@yahoogroups.com] >> *Sent:* Saturday, 7 October 2017 5:05 PM >> *To:* Homebrew_PCBs@yahoogroups.com >> *Subject:* Re: [Homebrew_PCBs] Does anyone know the process that IBM >> used to make this PCB >> >> Ton, >> >> The SLT refers to the silver colored modules that are on the boards. >> These were thick film hybrid circuits with aluminum covers. The >> modules were manufactured on an automated production line. Here is a >> reference: >> http://www.chipsetc.com/the-ibm-slt---solid-logic-technology.html. >> >> I think the layout on the board was done to accommodate the SLT >> modules with their square shape. The conductors on the board look >> something like a process that was used on some boards by the company >> I worked for. These were not etched conductors, but rather they were >> thin wires that were laid down on a layer of uncured resin. The way >> the wires were connected to the pads way by ending them in the area >> of the through hole, and when the hole was drilled and plated, the >> wires were connected together. I think the pads were plated on also. >> The wires were literally drawn by a pen like stylus that fed the wire >> through a center hole. Where there were crossovers, they wires look >> like they did on old schematics with their looped crossovers. These >> boards don't appear to use crossovers, probably because the >> crossovers are inside the SLT modules. I know we used those type >> boards for development, but I don't remember if we actually used them >> in production. These boards: >> http://www.hitachi-chemical.com/products_pwb_05.htm from Hitachi are >> similar to the ones we used, and the name Multiwire sounds familiar >> to me, we might have used the forerunners of this process. >> >> Harvey >> >> On 10/6/2017 9:33 PM, 'Tony Smith' ajsmith1968@... >> <mailto:ajsmith1968@...> [Homebrew_PCBs] wrote: >> >> >> Dunno how the boards are made, but that\u2019s called SLT - Solid >> Logic Technology. >> >> >> I think the idea behind the boards was traces are vertical in >> one direction, and horizontal on the flip side. You can still >> get protoboards to do this. As Stefan says it was an early >> attempt to automate everything (especially production) I think >> the board were designed by placing the little modules and the >> passives, then taking out the lines they didn\u2019t need. >> >> >> The extra pads were left because \u2018why not\u2019 \u2013 it\u2019s easier to >> leave them than to remove them (probably a standard mask) plus >> it makes rework easier. >> >> >> I did come across a good website on these once that will >> probably show me how wrong I remember it, might see if I can >> find it. >> >> >> Tony >> >> >> *From:*Homebrew_PCBs@yahoogroups.com >> <mailto:Homebrew_PCBs@yahoogroups.com> >> [mailto:Homebrew_PCBs@yahoogroups.com] >> *Sent:* Saturday, 7 October 2017 2:34 PM >> *To:* Homebrew_PCBs@yahoogroups.com >> <mailto:Homebrew_PCBs@yahoogroups.com> >> *Subject:* [Homebrew_PCBs] Does anyone know the process that IBM >> used to make this PCB >> >> >> Does anyone know the process that IBM used to make this PCB >> http://www.learnmorsecode.com/3380/index.html >> >> 30 years ago I was a computer programmer on an IBM system 34. >> >> IBM service technicians would sometimes open up the machine covers >> and I saw some really strange circuit boards inside. >> They did not look like anything found in any other electronic >> appliances. >> It looked like there was no etched traces on the IBM circuit >> boards that >> had square blocks..and every square block had solder in >> them..regardless if >> there actually was a component in the holes. >> All the components seemed to line up like houses on city streets. >> >> Recently I stumbled onto an IBM 3380 disk drive analog servo board >> and made these pictures with real up close details revealing what >> the strange boards >> were really made of... sort of. >> It turns out that the IBM PCBs had extremely thin traces on both >> sides of the PCB >> and in some places there was 3 traces in the space between the >> solder squares >> and >> that space was no wider than a penny. >> These traces would terminate at solder pads but would disappear >> from view..... >> never being actually visible touching a solder pad. >> Does anyone know what process made this circuit board? >> >> >> >> >> >> >> >> >> >> >> >> >> > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=icon> > Virus-free. www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=link> > > > <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> >
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Re: [Homebrew_PCBs] Does anyone know the process that IBM used to make this PCB
2017-10-11 by Rob