Re: omega race hig score save

Wow !

Great information William. I've had this same problem with my OR also. Although mine seemed to save it for a day or 2 and then stopped probably once the batteries voltage went down. I'm going to try 4 batteries and see what happens. Thanks.

-----Original Message-----
>From: William Boucher <boucher@mnsi.net>
>Sent: Oct 30, 2008 9:39 PM
>To: vectorlist@vectorlist.org
>Subject: Re: VECTOR: omega race hig score save
>
>I was looking at the schematic tonight just out of curiosity, even though I
>don't have the game myself.
>
>I found a datasheet for the 5101. Most of what I've been reading on some
>sites is that 3.6V at pin 22 really isn't quite enough to keep it up. That
>datasheet however specifies that 2V is enough to hold data. Apparently,
>4.8V will not hurt the thing, since it runs on 5V anyway when the game is
>on, so maybe you could simply try 4 cells. That would explain why both
>boards failed to hold the data when off. According to the datasheet, 4
>cells is overkill.
>
>It looks like the 5101 is enabled by a lot of things, one being that crazy
>over-complicated transistor circuit (Q102 & Q103) which looks like it's only
>there to tell the 5101 when the main power is on or off (via pin 17 chip
>select or CS2). If the pin 17 signal fails to come up, the 5101 will not
>enable writes to it so your hi-score would not be saved.
>
>Another is the pin 19 (active low "batram" which is chip select CS1) signal
>coming from the 74138 at location PN2. Then there's all the chips that
>enable the 74138 such as the 7404 inverters at S6 & PR1, and the nand gate
>at P4. A fault in any of these 4 chips would prevent the batram signal from
>being generated.
>
>Another is the pin 20 (active low write) signal. Is that being generated?
>If it is stuck high, it can't write. If pin 18 (called RD but is actually
>output disable) is stuck high, the data can't get out onto the bus and so
>the game can't read it.
>
>
>William Boucher
>----- Original Message -----
>From: "andre" <livnfree_can@yahoo.com>
>To: <vectorlist@vectorlist.org>
>Sent: Thursday, October 30, 2008 7:48 PM
>Subject: VECTOR: omega race hig score save
>
>
>>I have a couple boardsets I added battery packs to. I replaced the 5101 on
>>both as well. The battery packs are 3 x 1.2v for 3.6v as I believe that is
>>what the original single battery was rated at. But neither board saves the
>>high score still. I measure 3.5v on the 5101 with the machine turned off,
>>but it still restarts with the 'AE' generic highscore and not any other one
>>I get. Any ideas why its not working? The 5101 in the sockets were also
>>both checked for continuity and passed.
>>
>>
>>
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>
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Received on Fri Oct 31 02:01:53 2008