Re: omega race hig score save

JK6 doesn't appear to have anything to do with the 5101 problem. You might
want to try replacing the 74LS367 buffer at KJ9. It generates /mreq
signal. Boy, this one is proving to be a real bear to track down. I wish
you lived closer. I could bring over my Tech-Tools Digiview logic analizer
and clip it onto the 5101, run the game once and then we'd see exactly was
or was not happening.

William Boucher
----- Original Message -----
From: "andre" <livnfree_can@yahoo.com>
To: <vectorlist@vectorlist.org>
Sent: Sunday, November 02, 2008 7:02 PM
Subject: Re: VECTOR: omega race hig score save

> no scope..
> I checked pin 17 and it is 4.97v. Using a logic probe, it lit up solid on
> every pin solid except pin 8 (gnd).
> Currently I have replaced PN2, P4, PR1, S6, RP4. I also swapped out S7
> with one from another board. The diodes, transistors and resistors all
> check out in the section you mentioned. I replaced all .01uf 50v caps in
> that line to the 5101 (4 of them).. but no change. Is the chip read by
> this same stuff? Maybe its there and not being read? Is JK6 part of the
> read/write?
>
> --- On Sat, 11/1/08, William Boucher <boucher@mnsi.net> wrote:
>
>> From: William Boucher <boucher@mnsi.net>
>> Subject: Re: VECTOR: omega race hig score save
>> To: vectorlist@vectorlist.org
>> Date: Saturday, November 1, 2008, 11:28 AM
>> If you have a scope available, you should try to capture the
>> levels at pin 19 and at pin 18 when (or if) a pulse occurs
>> at pin 20. That would prove whether or not the control
>> signals were present and behaving properly.
>>
>> If you don't have a scope, and since you've likely
>> eliminated most of the possible logic related problems, I
>> think that it is likely that you have a discrete component
>> problem.
>>
>> Measure the voltage at pin 17 of 5101. It must be a logic
>> high while the game is on. This level provides an
>> active-high chip select. Without it, the chip does nothing
>> at all. This signal is provided by all that discrete
>> component stuff next to the 5101 in the schematic. The
>> zener D108, Q102 and Q103, R143 (and several other
>> res's).
>>
>> When the game powers up, it'll read the 5101 only once
>> and then display the results. When you get a new high
>> score, it'll try to save the value once but it'll
>> probably continue to display the correct value as long as
>> power is not lost. If the 5101 isn't working, you
>> wouldn't know it at that point.
>>
>>
>
>
>
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Received on Mon Nov 3 08:06:21 2008