Re: omega race hig score save

At 06:26 PM 10/31/2008, andre wrote:
>If I go into bookkeeping and can see my highscore before the game is
>powered down, then the chip 'is' being written to correct?

Unfortunately the answer is possibly. Someone would have to dig
through the OR code to determine if the high score you are seeing is
actually from the 5101 or just the information in RAM. It would be
nice if this information was ONLY stored in the 5101 but the
realities of slow access time (compared to RAM), limited lifetime,
component failures, and other factors made the game developers keep a
copy of the 5101 information cached in the RAM.

HTH,
Franklin

>--- On Fri, 10/31/08, 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: Friday, October 31, 2008, 12:39 AM
> > 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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>
>
>
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--
Franklin Bowen (Franklin@Bowen.net)
http://fmbbowen.com/ 
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