[vcf-midatlantic] Schematic work needed

[systems_glitch]

The bottom board here was how it arrived:

http://www.glitchwrks.com/images/s100/jump_board/original_front.jpg

Then some parts were stripped off:

http://www.glitchwrks.com/images/s100/jump_board/stripped_down.jpg

Then it had some stuff built on it:

http://www.glitchwrks.com/images/s100/jump_board/circuit_closeup.jpg

Then it got stripped down again, scanned, and became this:

http://www.glitchwrks.com/images/s100/reproducing_the_io2/production_board.jpg

I did the first stripdown before I got my Hakko 472D desoldering station. I
want to say I did the second stripdown for scanning without the Hakko as
well. It does require some practice and decent tools, but it's certainly
not something folks should run from.

Thanks,
Jonathan

On Wed, Aug 29, 2018 at 2:00 PM Chris Fala <chrisjpf33 at gmail.com> wrote:

> Ha, depopulate! You just scared away most people! :-) Desoldering is a
> skill I have yet to see demonstrated competently by many people, especially
> on YouTube.
>
>
>
>
> On Wed, Aug 29, 2018 at 8:25 AM systems_glitch via vcf-midatlantic <
> vcf-midatlantic at lists.vcfed.org> wrote:
>
>> I'd had the ISA card in the shop for a while and didn't get around to
>> mapping it out. I've explained to Evan that it's not a trivial process.
>>
>> I offered to depopulate the board and send it off to Mile High Test for a
>> scan + conversion to Gerbers, which are guaranteed to be 100% accurate,
>> but
>> that costs around $200-250. It's the same process I've used to reproduce
>> various Ohio Scientific and S-100 boards.
>>
>> Thanks,
>> Jonathan
>>
>> On Wed, Aug 29, 2018 at 2:58 AM RETRO Innovations via vcf-midatlantic <
>> vcf-midatlantic at lists.vcfed.org> wrote:
>>
>> > On 8/29/2018 1:15 AM, Evan Koblentz via vcf-midatlantic wrote:
>> > > I need someone to make two (relatively simple) schematics for me. One
>> > > is the IBM card for the Lego kit, and one is the Lego interface box.
>> > >
>> > > Here is one side of the IBM card:
>> > > http://snarc.net/lego_ibm_1.jpg
>> > >
>> > > Here is the other side:
>> > > http://snarc.net/lego_ibm_2.jpg
>> > >
>> > > Here's a picture of the top of the interface board:
>> > >
>> >
>> http://4.bp.blogspot.com/-DGOlTkGXj_Q/U8-T2uBG5iI/AAAAAAAAATY/7ra6gVkSKg8/s1600/LEGO_ControllerBoard_Top.jpg
>> > >
>> > >
>> > > Here's the bottom of the interface board:
>> > >
>> >
>> http://lukazi.blogspot.com/2014/07/lego-legos-first-programmable-product.html
>> > >
>> > >
>> > > Here's a document Dan R. made of the board a year or two ago:
>> > > http://snarc.net/9750.png
>> > >
>> > > Now here is the catch..... I absolutely MUST have a complete, perfect,
>> > > finished schematic of the IBM card and the interface board by a week
>> > > before Maker Faire -- so let's say the deadline is Friday, Sept. 14.
>> >
>> > Do you have a backup plan?  I say that because I professionally feel
>> > that creating a working and tested schematic within your timeline is
>> > going to be nearly impossible.
>> >
>> >   * The first board is two sided, and those typically need to be
>> >     unsoldered to ensure all traces under the ICs have been mapped. One
>> >     can try to use a multi-meter, but there are pitfalls
>> >   * Even if the schematic is doable, there's no way to truly ensure it's
>> >     perfect unless one make a spin of the PCB, populates it, and tests
>> >     it.  unless one wants to spend $250.00, it takes about 2 weeks to
>> >     spin a PCB.
>> >   * Though the other board looks to be single sided, all of the items on
>> >     the board must be described and validated.  The toroids in the
>> >     center and right seem particularly problematic, as one needs to
>> >     determine the uH, turns, and such of the items in order to be
>> >     perfect.  As well, those TO-220 transistors (or maybe they are FETs)
>> >     sandwiched in between the connectors need to be desoldered or
>> >     somehow moved so the markings can be read.  The LEDs need to be
>> >     scoped to determine their mA rating, etc.
>> >
>> > I'm not trying to rain on the parade, but I do want to inject some
>> > realism into the request timeline.  Doing such a reverse engineer will
>> > probably take a month or so, assuming someone squeezes it into their
>> > normal workflow and they do this regularly.
>> >
>> > Someone already made a schematic of the Apple II card:
>> > >
>> >
>> http://lukazi.blogspot.com/2014/07/lego-legos-first-programmable-product.html
>> > >
>> >
>> > Regrettably, it looks like the Apple uses a different schematic
>> > completely (It uses a VIA instead of the IBM PC discrete TTL) and so
>> > this schematic will not help.
>> >
>> > Jim
>> >
>> >
>> > --
>> > RETRO Innovations, Contemporary Gear for Classic Systems
>> > www.go4retro.com
>> > store.go4retro.com
>> >
>> >
>>
>