Homebrew PCBs

Yeah, that was a mistake on my part - I was one off in my email list. 
Too early in the morning.

DaveD

On 10/11/2017 11:18 AM, 'Tony Smith' ajsmith1968@... 
[Homebrew_PCBs] wrote:
>
> If she needs a pop-up canopy, then Dave\u2019s your man.
>
> I do believe that wasn\u2019t meant for us.
>
> Tony
>
> *From:*Homebrew_PCBs@yahoogroups.com 
> [mailto:Homebrew_PCBs@yahoogroups.com]
> *Sent:* Thursday, 12 October 2017 1:07 AM
> *To:* Homebrew_PCBs@yahoogroups.com
> *Subject:* Re: [Homebrew_PCBs] Does anyone know the process that IBM 
> used to make this PCB
>
>
>
> Who is Robyn ?
> My daughter's name is Robyn.
>
>
> On 10/11/2017 04:17 AM, Dave Daniel kc0wjn@... 
> <mailto: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@...
>     <mailto: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>
>         [mailto:Homebrew_PCBs@yahoogroups.com]
>         *Sent:* Saturday, 7 October 2017 5:05 PM
>         *To:* Homebrew_PCBs@yahoogroups.com
>         <mailto: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?
>
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