Re: Tempest Schematic error?

Best guess (having NEVER worked on one of these) would be the vector state
PROM at D7.

On Sat, Jun 26, 2010 at 11:51 PM, Kevin Moore <talon.k@gmail.com> wrote:

> I haven't tried tying the others high. But no they don't pulse.
>
> I've been trying to track down the VGCK, but so far I haven't been able to
> find the origin. Guess my eyes are getting tired from looking at these
> schematics.
>
> It's looking like the VSM is dead, and it may be due to the VGCK.
>
>
>
> On Sat, Jun 26, 2010 at 11:21 PM, Rodger Boots <rlboots2@gmail.com> wrote:
>
>> I was only getting DVY8-11.
>> So you're saying ONLY F5 is working? I could believe that...
>>
>> Having pin 1 tied high might not be that important. A better question is
>> why pin 1 on the other chips is low---do they pulse at all???
>>
>>
>>
>> On Sat, Jun 26, 2010 at 9:32 PM, Kevin Moore <talon.k@gmail.com> wrote:
>>
>>> 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 Sun Jun 27 01:03:50 2010