Vectorlist Archives: RE: Assistance with Star Wars w/Clay's ESB

From: Clay Cowgill <c.cowgill_at_comcast.net>
Date: Tue Feb 22 2011 - 18:56:36 EST

I think I have a few untested (maybe only partially completed) ones, but
once things get back to 'normal' here I really want to finish my 4.0 version
instead. I do have my "DEPROM" boards (gets rid of all the bipolar mathbox
PROMs) and the new display correctors too. I've only had time to build up
and ship our a couple handfulls of those to people that have emailed me
directly though. :-/

I'll look in storage at least for the partial SW/ESB's I (think) I saw a
while ago. I was hoping to get 6809's from Dave @ RAM controls, but I had
to get a refund from Paypal since I never got the order. Getting new ones
isn't *critical*, but I really like being able to solder a new one in place
and fully test things before shipping. I got some of the most f'd up boards
you've seen in your life back from people trying to solder their own 6809's
in place. ;-) (If your soldering iron has a 'trigger' and a 'light bulb' on
it-- please don't. :-)

I'm *just* now coming up for air after three-months of building LED lighting
systems and doing stuff at the construction site for Ground Kontrol, so
it'll be a while before I even make it through my back emails at this point.
:-P

-Clay

P.S. Maybe a little light on vector content, but if you'd like to see the
arcade remodel here's some coverage: http://tinyurl.com/4j6aqpu
We're still running Tempest, Asteroids, and Star Wars on a small "vector
row". You can just see the side of Tempest in the top left here:
https://picasaweb.google.com/lh/photo/USklFrxePL2OvDUxsg0BcA?feat=directlink
;-)

The vector games have been pretty good-- Star Wars seems to lose a
deflection transistor ever year or so, but it's been running a DEPROM board
for probably close to two years now with no issues. Oh, and my molded
plastic Star Wars triggers have been in it for close to 18 months without a
failure either.

_____

From: owner-vectorlist@vectorlist.org
[mailto:owner-vectorlist@vectorlist.org] On Behalf Of Maxstang
Sent: Tuesday, February 22, 2011 3:01 PM
To: vectorlist@vectorlist.org
Subject: Re: VECTOR: Assistance with Star Wars w/Clay's ESB Kit --- SW
novram clobber?

Don't suppose you have the parts lying around to make a few more SW/ESB
kits, do you Clay?

Sent from my iPhone

On Feb 22, 2011, at 10:50 AM, "Clay Cowgill" <c.cowgill@comcast.net> wrote:

Worth noting that there is a checksum in the data written to the 2212. If
the checksum and data do not match, the NVRAM is wiped clean by the code on
the next startup. I'm still kinda liking the "more capacitance on +5EAROM"
idea for the time being. Of course there might have been a reason why Atari
had that value so low (like to prevent the NVRAM from trying to power the
rest of the board from +5EAROM back through the address/databus pins or
something).

I guess you could always just double the value of C93 (for twice the load)
and be relatively safe (as opposed to 'too much').

Another thought-- do you have *another* new 2212 to try using? Maybe the
one you have is just particularly finicky? Or also possible-- maybe your
C93 (or C94 mod) has significantly degraded and you're just on the bleeding
edge of "good enough"...

Mark's idea about the C94 mod is a good one too.

-Clay

_____

From: owner-vectorlist@vectorlist.org
[mailto:owner-vectorlist@vectorlist.org] On Behalf Of Mark Shostak
Sent: Tuesday, February 22, 2011 8:42 AM
To: <mailto:vectorlist@vectorlist.org> vectorlist@vectorlist.org
Subject: Re: VECTOR: Assistance with Star Wars w/Clay's ESB Kit --- SW
novram clobber?

Or... Here's a completely different possibility:

Have you tested or verified the presence of "anti-corruption capacitor" (my
words) C94?

This cap "...maintains E2PROM data integrity..." "...during power-up or
power-down...", quoting Xircor.

It would be interesting to get a measurement on this cap, as it could
potentially explain a lot of "flaky" NVRAM behavior in SW boards.

HTH
-Mark

On Tue, Feb 22, 2011 at 9:38 AM, Jess Askey < <mailto:jess@askey.org>
jess@askey.org> wrote:

So if switching to ESB during power off does it then the only things I can
think of would be that SW is actually getting corrupted while ESB is writing
to the NVRAM. So... try this...

a. Do what Joel suggested first

1. put in SW mode... put up a high score.
2. Power Down.... remove the SW NVRAM (on Clay's PCB if I read that right)
3. Switch to ESB... turn on game
4. Put up an ESB high score
5. Power down... replace the SW NVRAM
6. Switch to SW (don't forget this or you will have to start over)
7. Bring up SW and data should be good still.

So, with that, like Joel said on his check, you can see if it is chip
specific then you can see if there is something funky in my process. If my
process works and SW memory is still OK, then there must be something going
on with the chip select between the two NVRAMs which is letting ESB write
data to the SW NVRAM... when SW is powered back on and the data isn't
checksumming correctly, it will restore it to DIP settings and overwrite it.
If the memory in SW is still corrupt after this process, then it has
something to do with the powerdown with the select switch being in different
positions.

jess

On 2/22/2011 8:22 AM, Joel Rosenzweig wrote:

It would be worth swapping the two 2212 chips between SW and ESB to see if
the failure moves with the chip or stays with the socket. If it moves with
the chip then that's one debug path. If it stays with the socket then that's
a different one.

Joel

Sent from my iPhone

On Feb 21, 2011, at 11:56 PM, "Altan ( <mailto:altan@aol.com>
altan@aol.com)"< <mailto:altan@aol.com> altan@aol.com> wrote:

Well, I think the reason this is hard to figure out is because the behavior
is just plain screwy.

I replaced the SW 2212 a couple days ago and it definitely started storing
settings.
For several days, it would power up with free play and my settings.
About 4 hours ago, I got a high score (yeah! ... #3). I turned the game
off.
I just turned it back on and the settings were lost (as well as the high
score). Boo!

So we can most likely conclude from this that switching from ESB to SW isn't
the root cause. Maybe I was just unlucky that the failure occurred at those
times --- leading me to assume they were correlated.

What's odd is that the novram test passes. FWIW, the novram test also
passed with the original 2212.

What does that tell us when the novram test passes? Anyone know what Atari
actually did for the novram test? Did they write a pattern into the ram and
then tell the chip to store it, then clear the pattern from ram and then ask
the chip to restore it from novram? I'm wondering if knowing why the
novram test passes might help explain what I'm seeing.

Thanks again to everyone is hash chimed in --- or will do so :)

... Altan

On Feb 21, 2011, at 11:46 PM, Altan (GAPAS) wrote:

Joel, you have it correct.

SW saves fine.
ESB saves fine.
Switch from ESB to SW (with power off) and SW loses settings

... Altan

On Feb 21, 2011, at 11:40 PM, Joel Rosenzweig wrote:

If the timing was wrong, wouldn't it fail to save the score in that 2212 all
the time? I thought he said that SW saved the scores now, but, when
switching back from ESB, SW was re-initialized.

Maybe I'm misreading him again.. don't know.

Joel

On Feb 21, 2011, at 11:33 PM, Jess Askey wrote:

I did lots of fanagling with the NVRAM on my I,Robot when it had trouble
saving settings and indeed, Atari seemed to balance the /SAVE line with the
timing of the +5V NVRAM supply *just right* to make the NVRAM save data
right before power disappeared. Technically, if you doubled the load, the
power supply would drop in about half the time so putting a big cap in
parallel with C93 seems like the best bet... at least to eliminate that
possibility.

On 2/21/2011 8:42 PM, Clay Cowgill wrote:

I'm assuming this is the 2212 used for SW novram. Is that right?

I'm 99% sure that's right. (Sorry, it's been a long time since I had to
look at/think about that. ;-)

The idea was that you could take your existing Star Wars settings and high
scores and move them over to the daughterboard without losing anything.

The only thing that comes to (my) mind at the moment is that maybe with two
NOVRAMs sharing their connections (except for the chip select which is muxed
by the game select switch) maybe the 'new' SW 2212 doesn't have enough time
to store the SRAM copy of the memory to the NV portion of the chip before
the EAROM power goes away.

For grins, you might try something like putting a big electrolytic cap
across the "+5EAROM" power and ground pins of the 2212's on the
daughterboard. (Like a 470-1000uF or something-- you could also put it in
parallel with C93 on the SW board-- careful with the polarity.)

-Clay

P.S. My apologies to anyone contacting me in the last few months if I
missed replying to you. We *just* finished getting Ground Kontrol back to
our permanent location after a huge three month remodel, so it'll be several
weeks still before I get my head above water again. We were doing 120+ hour
weeks there towards the end. ;-)

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Received on Tue Feb 22 18:57:12 2011

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RE: Assistance with Star Wars w/Clay's ESB Kit --- SW novram clobber?