He said relatively simple, I don't think Evan needs anything fancy, I/O stuff would probably suffice. What lines carry what signals to and from the computer and device, best guess. b On Wed, Aug 29, 2018 at 8:24 AM systems_glitch via vcf-midatlantic < vcf-midatlantic@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@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/s1...
Here's the bottom of the interface board:
http://lukazi.blogspot.com/2014/07/lego-legos-first-programmable-product.htm...
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.htm...
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
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