Homebrew PCBs

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?
>
>
>
>
>
>
>
>
>
>
>
>
>
> 



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