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  1. Well this is an LCD from 1983. I am guessing...

    Well this is an LCD from 1983. I am guessing Xerox/Sunrise acquired something pre-existing. I'm wondering how complicated they are to figure out, and if it would be possible to find a similar 3...
  2. I suppose the odds of finding a replacement would...

    I suppose the odds of finding a replacement would be pretty low huh?
  3. Is it possible to repair old, cracked LCDs?

    I've noticed if I press on this one while operating it I can see things. Is there anything I could do to sort of, jury rig it to be somewhat usable?
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    Finally got some time to play with the Xerox 1810...

    Finally got some time to play with the Xerox 1810 again. Here's some pics of the insides, along with a link to my Google Drive with high res versions.

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    Fixed. https://youtu.be/32LqmGW4uhE Not...

    Fixed.

    https://youtu.be/32LqmGW4uhE

    Not sure which fixed it - I found the leg of the 74LS08 at U52 to not be fully in the socket, but it looked like it was making contact. However, remembering...
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    So I read the SMC 9007 datasheet, and it says...

    So I read the SMC 9007 datasheet, and it says that chip has registers that track cursor location. I am guessing that's updated by the 'cursor' circuits on page 4 of the schematic.

    Now, I know...
  7. Sticky: I keep thinking about offering to do a talk on my...

    I keep thinking about offering to do a talk on my TVT build. But between work and my fear of embarrassing myself with my lack of technical knowledge.. yeah. :) But I am definitely getting down...
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    Well, I got most of the way there. Basically I...

    Well, I got most of the way there. Basically I removed the 74LS08 I had in place. I then carefully cleaned out the holes. Next, I used those old style pin strips:

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    That was on the...
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    Here's the whole one. There are a couple...

    Here's the whole one. There are a couple different revisions of the video board but at least from what I can tell mine is a Rev 3.
    ...
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    This is the trace I'm having trouble finding: ...

    This is the trace I'm having trouble finding:

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    I'm wondering if this is even something more simple.. like maybe that hidden 5V rail being broken and not getting power to one of the other...
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    I'm reasonably sure it is multilayer. When I...

    I'm reasonably sure it is multilayer. When I hold it up to light I can see what look like tracks buried in the epoxy. Seems like the 5v rails are in that layer, I can see two traces attaching to...
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    I'm reasonably sure it is multilayer. When I...

    I'm reasonably sure it is multilayer. When I hold it up to light I can see what look like tracks buried in the epoxy. Seems like the 5v rails are in that layer, I can see two traces attaching to...
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    Thanks Hugo. Before attempting my repair I...

    Thanks Hugo.

    Before attempting my repair I saw signals at pins 12 and 13 on the 74ls08, and nothing on pin 11. I verified it a few times.

    So I removed it and subbed in with another, hoping...
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    Thanks Holden. And a lot of what you've...

    Thanks Holden.

    And a lot of what you've described is what I do nowadays.. my desk is festooned with printouts of the schematic, datasets for ICs, truth tables and so on. That was one of the...
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    I'm trying, Chuck. And bits of it are starting...

    I'm trying, Chuck. And bits of it are starting to make sense. I'm not an engineer or a math wiz, so it takes me longer to grasp concepts. But at least I feel like I'm starting to ask the right...
  16. Neat. I'm not sure if it's something I would buy...

    Neat. I'm not sure if it's something I would buy but I appreciated David's in-depth explanation as to how it would work.

    I too was a little bit 'meh' by the case design ideas thus far and would...
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    For sure. One thing I'm not clear on.. when you...

    For sure. One thing I'm not clear on.. when you see on a schematic multiple connections coming together as one and then going out from there collectively to another page.. does that mean they are...
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    Yeah, darn it.. I think this board has more than...

    Yeah, darn it.. I think this board has more than 2 layers. I think when one of the vias in the 7408 socket broke, it broke a connection between that pin and wherever it goes. At this point i'm...
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    I am seeing vias that go from one side to the...

    I am seeing vias that go from one side to the other but appear to go nowhere from there.. is that possibly a sign that this board has more than 2 layers?
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    Is there anything that activates or shuts off a...

    Is there anything that activates or shuts off a 2732 internally? Or if you see data going in, does that mean there should always be data coming out? I'm seeing data going in no problem on all the...
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    So I removed and installed another 7408. Now I...

    So I removed and installed another 7408. Now I am getting no text at all and a cursor that immediately is placed mid screen. The machine will not try to boot.

    I checked the EPROM... there is...
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    No - but I did connect composite to that pin...

    No - but I did connect composite to that pin anyway, and could clearly see text being output. So I'm reasonably confident that is working.

    I have traced the circuit further down though, and have...
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    Looking for insight into video design

    So I'm pretty close, I think, to solving my 'no text's situation with this Hyperion. I'm just trying to understand the circuit a little better. The datasheet for the SMC 8021 says you can connect...
  24. Thread: Fake ICs

    by falter
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    The other thing you kind of wonder about is...

    The other thing you kind of wonder about is motive... these chips only cost me about $60. Hardly seems worth the effort to fake for an obscure chip few people will need or use. If it was a ceramic...
  25. Thread: Fake ICs

    by falter
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    Is it possible they could take old stock parts,...

    Is it possible they could take old stock parts, and relabel them with the intent of freshening them up for sale, with 'production' dates being substituted for warranty start dates? The date code on...
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