Tech: Mars coin mech reprogramming

[John Bennett]

[ukvac] Tech: Mars coin mech reprogramming
Hi all...

I have a Mars MS111 coin mech which is working, but hasn't been
reprogrammed for the new 50p coins - it still accepts the old ones!

Under the side cover is a 82S126 PROM, which I'm guessing contains
the data about the coins.

Would I be right in thinking that if I can find a fully working and
up-to-date MS111 and copy the PROM from it and put it in my mech, it
will then take all four coins including the new 50p?

Any help greatfully appreciated

Dave



DATA Imported from archives: originally posted by canonman75 (david@smethurst75.fsnet.co.uk)

 

[guddler]

RE: [ukvac] Tech: Mars coin mech reprogramming
Indeed, and if you have a programmer that can program them you can even get
away without having to find a new prom too as you can turn the prom upside
down and use the other half (I know what I mean, if you have a programmer
that can do them then I'll elaborate!).

The only thing to bear in mind is that when you do them properly, you
program the chip with the tolerances worked out from passing coins through
the actual mech the chip is going to live in, so you may get away with this
approach, you may not (YMMV as they say on the net!), depends on the
mechanics and reliability of the mech too...

If you don't have a programmer that can program the proms then I can offer a
full reprogramming and calibration service for the MS and ME series coin
mechs as I have a proper test / programming unit for them.

Never worked out a price for the service though. The chips are obsolete. As
far as I know very much so as Swallow show on their site that if the chip is
not reusable then they wont even do anything with it, just ship the mech
back to you and charge you the postage.

LMK if I can be of assistance.

Failing that I can always sell you a complete replacement that will accept
all modern coins, but now I'm waffling :O)

Gudd.

 

[John Bennett]

[ukvac] Re: Tech: Mars coin mech reprogramming
Hi Martin

Thanks for chipping in with some useful info

I do have a Bipolar PROM programmer, a Hi-Lo BPP-01, so I may be able
to try what you've suggested. You'll have to elaborate on 'turning
the PROM upside down' as I can't quite see what you mean by it.

I notice that, on andys-arcade, Andy Welburn has some 7052's in
stock, and these are equivalent to 82S129's according to my data
sheets. Would these be a suitable equivalent, and could Andy confirm
that he has some left in stock?

If I remember correctly, the 82S126 has open collector outputs and
82S129's have tristate outputs. Would this be a problem in this
circuit?

Failing that, I may be interested in sending the unit to you,
depending on how much you quote me for it. Or even buying another
MS111, again depending on the cost.

Cheers,

Dave



DATA Imported from archives: originally posted by canonman75 (david@smethurst75.fsnet.co.uk)

 

[P-Man]

Re: [ukvac] Re: Tech: Mars coin mech reprogramming
yeh i have plenty of 7052's to last until the next ice age...

I *might* have a small number of 74s129's in the form of 82s somethings that
i found the other day, i'll have to check exactly what they are as i don't
remember buying them, but i seem to have them

It does depend on the circuit, but i usually find tri-state devices are ok
in place of open-collector devices as most design engineers put resistor
paks (or placements for them) in place to account for either type... I've
never touched modern multi-mechs tho as i've never had a need for them, all
my machines are far too old for them, despite the fact i have a huge box of
them hehe...

Andy Welburn
www.andys-arcade.com

 

[guddler]

RE: [ukvac] Re: Tech: Mars coin mech reprogramming
I'll elaborate more thoroughly when I've had a chance to go and dig out the
intructions for my mars programmer (tomorrow during the day if I remember!), but
for my programmer, I quite literally turn the chip upside down so if the socket
is vertical (which it is!) then the notch would be put at the bottom rather than
the top (and vice versa), and thus the other half of the addressable memory gets
programmed.

I need to dig out the instructions to see if that relates to "real-world"
programmers, or whether it's a quirk of this thing I have - I think it's a quirk
of the IC though so should apply to you too :O)

I do recall the instructions saying to clip one of the legs off when you've done
it. Not so much as a requirement (IIRC it's a NC pin!), more to remind you that
this chip has already been used twice and cant be used again. SO, if the prom
has a leg missing then it will have already been done.

I suppose alternatively, I could be pursuaded to dig out one of the programmed
units and sell you a ready programmed chip :O)

I seem to remember having quite a few NOS blanks. Will pull it all down off the
top of the bookcase and dust it off tomorrow, when I get a spare moment!

Martin.

> Hi Martin
>
> Thanks for chipping in with some useful info
>
> I do have a Bipolar PROM programmer, a Hi-Lo BPP-01, so I may be able
> to try what you've suggested. You'll have to elaborate on 'turning
> the PROM upside down' as I can't quite see what you mean by it.
>
> I notice that, on andys-arcade, Andy Welburn has some 7052's in
> stock, and these are equivalent to 82S129's according to my data
> sheets. Would these be a suitable equivalent, and could Andy confirm
> that he has some left in stock?
>
> If I remember correctly, the 82S126 has open collector outputs and
> 82S129's have tristate outputs. Would this be a problem in this
> circuit?
>
> Failing that, I may be interested in sending the unit to you,
> depending on how much you quote me for it. Or even buying another
> MS111, again depending on the cost.
>
> Cheers,
>
> Dave
>
>
>

 

[John Bennett]

[ukvac] Re: Tech: Mars coin mech reprogramming
Hi Martin

I've had a look at the pinouts for the 82S126/82S129, and I can't see
how you're suggestion of turning the chip upside down can work. As
the power pins are at pin 8 and pin 16, you'd be reversing the supply
to them if you turned the chip upside down?

Maybe I misinterpreted what you meant?

Anyway, I would quite happily let you sell me a good PROM to try it
with, or send it to you for a proper setting up.

You'll have to let me know the costs...

Cheers!

Dave



DATA Imported from archives: originally posted by canonman75 (david@smethurst75.fsnet.co.uk)

 

[guddler]

RE: [ukvac] Re: Tech: Mars coin mech reprogramming
Okay, as ever I forgot all about this earlier! I just got in, so I went and
dug the "manual" (2 typed sheets) for the programmer out - was going to take
a pic of the calibration unit, but it's buried under... You guessed it, a
pile or Mars mech's :O)

Anyway, as per usual it's me that's misinterpreted my memory (I blame
corrupt ram based on a misspent youth!), and is spouting complete bollocks!

The chip, not surprisingly doesn't get put in the mech upside down - that
would clearly pop it. The calibrator instructions talk of "top" and "bottom"
when they refer to the lower address space and upper address space which is
what threw me )

Anyway, all it's doing is the mech only uses half of it's address space, so
you can reprogram it leaving pin 15 out of the mech (chopped off if you
like) to reuse the same chip.

This applies to N82S126N / N82S126AN / DM74S387, all of which can be used
twice for an MS series mech. You can use either a N82S130N/AN in an ME
series mech. It is possible to use one of the smaller proms for the ME
series, but if you do this you can only use it once. I guess that makes
sense. Note, those chips are what THIS unit can handle, I guess it doesn't
list the tri-state devices as it cant do them. Perhaps?

SO, in your case, you have a couple of options depending on what you have at
your disposal, but I'll take it off-list now as it's not really relevent to
anyone else from this point on.

Martin.