Originally Posted by kreed

On Dec 28, 5:20*am, Andy Bilton Andy.Bilton.
wrote:
kreed;666813 Wrote:



On Dec 27, 1:21*am, Andy Bilton Andy.Bilton.
wrote:-
Hi all,

First off Merry Christmas 2010 to all on the forum!

I have a problem with my NSM Peformer Classic. *Comes up with error
messsages on switch on so I program it to fix the error only problem
is
when machine is switched off and back on again machine seems to
'forget'
that I fixed the problems. *Also machine can't seem to 'remember' that
I
have it programmes for freeplay.

I've done nothing drastic to it so I'm figuring that something's wrong
with the memory on the machine. *I can find no battery so I'm figuring
this type of jukebox does not have a battery backed up memory but I
can't find anything about memory in the manual (which I have).

Does anyone have any ideas what kind of memory system the NSM
Performer
Classic uses and how I can resolve issues with it please?

Many thanks

Andy

--
Andy Bilton-

Typically a 5101 or a 6116 / 6264 Ram are used in games / jukes for
this purpose, but I don't know what NSM use.

If there is no battery or chip as listed above - it could have an "e
squared" memory. *These would typically be an 8 pin IC. *These are
FLASH type memory, and dont need a battery. * They do wear out after
about 10,000 writes (especially older ones) though and start to fail.
These were also used on "off road" and "Lethal Enforcers" games and I
have replaced this IC on both these games due to failure. (off road
died as in one location they were forever setting new high scores and
we believe this is what nuked the chip)

Considering that if it holds coin and popularity data - its extremely
likely that these RAM locations would be incremented (written to)
every time a coin is inserted, or a selection is played, or a setting
is changed. *If there is an "hours on" or "number of times turned on"
function - then these would be written in addition every hour or every
time the machine is turned on. * It is also possible that multiple
data locations are changed with each operation (several writes) if
they have a checksum or other method of detecting corrupt data.

The other alternative that was popular was a "Dallas" chip.
These were a rectangular block that sits higher than a ROM and had
battery and ram enclosed inside this block. *If faulty you will likely
need a new one as the battery is sealed inside. They should have
"Dallas semiconductor" written on them.

You may be able to cut the top of the thing open and find and replace
the battery - (from memory its in the upper part of the chip) but
there is a risk of rendering it unusable.

Thanks for your post Kreed. *I had another look at the manual and it
says that the temporary memory is stored in 'battery bufered RAM'. *This
would appear to be a chip noted as IC 5 which has 20 pins. *I had a real
good luck on the board that this chip is set in and can find nothing
that looks anything like a battery. *I even took the chip out but there
was nothing resembling a battery underneath. *Whilst out I noticed the
chip has the following numbers underneath 48T18A9 and H228236. *From my
limited knowledge gained from tinkering with pinball machines I suspect
this to be one of these 'flash' RAM chips as it has a label stuck over
the top of it to cover up the 'flashable' spots.

They are not FLASH ram, these are Eprom. They can only be erased with
UV light exposure
then re-programmed. There is a pin taken to +12 / 24V (depending on
the type) during this programming. (called burning).

FLASH is similar to what is now used in digital camera cards etc. You
write something electrically into it and it stays there
indefinitely without any power. AN EPROM does the same thing, but you
need the 20 min of UV to erase it.
It doesn't need special voltages to do this.

Both can be electrically rewritten a certain number of times, fairly
quickly and can have unlimited reads.

Normal RAM can be read/written to indefinitely and is very fast. It
will lose this content though without power. CMOS (low power) RAM
has been used for a long time in Pinballs, Games, Jukeboxes etc for
holding data, as well as sometimes also being used as general purpose
RAM for the CPU during its operations. (IE - All ROWE Laserstar CCC
Boards).

The battery is used to keep power to this RAM while the mains is
turned off so the content is not lost.



Can anyone shed any further light on my conundrum please?

Cheers

Andy

--
Andy Bilton