Re: Tempest Schematic error?

From: Kevin Moore <talon.k_at_gmail.com>
Date: Sat Jun 26 2010 - 22:32:03 EDT

Versions 1, 2, 3 all show the same thing. Looks like a cut and paste. Pin 1
definitely get's hooked to pin 2 solder pad joining them. I would have never
noticed, but I have a video problem, and I was only getting DVY8-11. When I
started probing I noticed that pin 1 was high on F5, but not on any of the
other Ls194 chips. So that got me off on a wild goose chase trying to figure
out why pin 1 of the rest of the circuit wasn't connected to F5 pin 1.

In any case, none of my latches are toggling, nor any of the states going
into f7.

So now I'm doing the logic probe shuffle in circles.

On Sat, Jun 26, 2010 at 9:18 PM, Kevin Moore <talon.k@gmail.com> wrote:

> Yeah it's an ls194 alright. But the board/s I am looking at all have pins 1
> and 2 shorted.
>
>
>
> On Sat, Jun 26, 2010 at 8:52 PM, Rodger Boots <rlboots2@gmail.com> wrote:
>
>> Printing 1 schematics show same thing, no pin 1-2 connection and chip is
>> an LS194.
>>
>>
>> On Sat, Jun 26, 2010 at 8:48 PM, Rodger Boots <rlboots2@gmail.com> wrote:
>>
>>> The schematics I pulled up say F5 is an LS194 with pin one being LATCH1
>>> (inverted) and pin 2 going to P R15. But there is a connection dot at pin 1
>>> and I am using printing 2 of the schematic, so on printing 1 they MIGHT have
>>> been incorrectly connected together.
>>>
>>>
>>> On Sat, Jun 26, 2010 at 6:33 PM, Kevin Moore <talon.k@gmail.com> wrote:
>>>
>>>> So I was looking through the schematics today, and it seems that there
>>>> is a problem in the vector-generator data shifter section. Specifically with
>>>> F5. Perhaps I'm just confused, so I thought I would ask and see. But it
>>>> looks to me like pins 1&2 are tied together. Instead of having /Latch1 going
>>>> into pin 1.
>>>>
>>>> Also could someone explain to me what the P,R15, and P,R31 lines are?
>>>>
>>>> Thanks,
>>>>
>>>> Kevin
>>>>
>>>>
>>>
>>
>

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Received on Sat Jun 26 22:32:06 2010

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