Discussion:
NVRAMming it
(too old to reply)
phantomm_1
2010-02-16 21:47:40 UTC
Permalink
NVRAM

Which pins on the NVRAM chip does one need to
connect a external Battery to, in order to fix the
weak or dead battery problem.

I've a Falcon here that I use for testing various modifications
on.
My NVRAM chips all seem to be the same type, which I
think is known as Type A.

I need to know what the original voltage was of the battery
in the NVRAM chip. And which pins that I can get a
voltage reading from, and for trying a external battery
modification.

***@suddenlink.net
x***@cix.compulink.co.uk
2010-02-18 18:17:59 UTC
Permalink
Post by phantomm_1
Which pins on the NVRAM chip does one need to
connect a external Battery to, in order to fix the
weak or dead battery problem.
I've a Falcon here that I use for testing various modifications
on.
My NVRAM chips all seem to be the same type, which I
think is known as Type A.
I don't know about your Falcon, but on my Falcon and that of
several other Cheshunt Computer Club members, the battery had to
be connected to wires in the chip itself, after carefully removing
the top layer. and not to any of the pins. My chip was marked
48T87 C and Z143906. The battery is a single small lithium cell.

In the end I found it easier to replace the NVRAM chip - they cost
only a few dollars. Fitted a socket at the same time so I can
change it easier when this chip's battery expires in a few years
time. This needed a hole cut out of the shielding above the chip
(or omitting that part of the shielding). Keyboard fits over it OK.

Regards, /Peter/
phantomm_1
2010-02-18 22:07:07 UTC
Permalink
Post by x***@cix.compulink.co.uk
Post by phantomm_1
Which pins on the NVRAM chip does one need to
connect a external Battery to, in order to fix the
weak or dead battery problem.
I've a Falcon here that I use for testing various modifications
on.
My NVRAM chips all seem to be the same type, which I
think is known as Type A.
I don't know about your Falcon, but on my Falcon and that of
several other Cheshunt Computer Club members, the battery had to
be connected to wires in the chip itself, after carefully removing
the top layer. and not to any of the pins. My chip was marked
48T87 C and Z143906. The battery is a single small lithium cell.
In the end I found it easier to replace the NVRAM chip - they cost
only a few dollars. Fitted a socket at the same time so I can
change it easier when this chip's battery expires in a few years
time. This needed a hole cut out of the shielding above the chip
(or omitting that part of the shielding). Keyboard fits over it OK.
Regards, /Peter/
Hi,

I have 2 Falcons apart down to the motherboards, One for experiments
and the other one has a problem that I'm trying to fix.

Both have similar looking NVRAM chips, 2nd set of numbers are the same
but top number is different and numbers on top left corner are different.
I've took a snap pic of each, I'm going to try e-mailing them to you.

Pass them around to anyone, who knows something about these.
Just don't post them anywhere without asking me please.
I consider my snap pics, as part of my work.

Anyone who uses a Falcon or does work on chips like this and
wants to see the pics, just e-mail me and I'll e-mail them to you.

thanks,
Barry
***@suddenlink.net
***@bellsouth.net
Dave
2010-02-19 18:39:04 UTC
Permalink
Post by phantomm_1
Post by x***@cix.compulink.co.uk
Post by phantomm_1
Which pins on the NVRAM chip does one need to
connect a external Battery to, in order to fix the
weak or dead battery problem.
I've a Falcon here that I use for testing various modifications
on.
My NVRAM chips all seem to be the same type, which I
think is known as Type A.
I don't know about your Falcon, but on my Falcon and that of
several other Cheshunt Computer Club members, the battery had to
be connected to wires in the chip itself, after carefully removing
the top layer. and not to any of the pins. My chip was marked
48T87 C and Z143906. The battery is a single small lithium cell.
In the end I found it easier to replace the NVRAM chip - they cost
only a few dollars. Fitted a socket at the same time so I can
change it easier when this chip's battery expires in a few years
time. This needed a hole cut out of the shielding above the chip
(or omitting that part of the shielding). Keyboard fits over it OK.
Regards, /Peter/
Hi,
I have 2 Falcons apart down to the motherboards, One for experiments
and the other one has a problem that I'm trying to fix.
Both have similar looking NVRAM chips, 2nd set of numbers are the same
but top number is different and numbers on top left corner are different.
I've took a snap pic of each, I'm going to try e-mailing them to you.
All the NVRAM chips I have seen are basically a RAM chip with a large
plastic cover and cell underneath. If you don't prise the plastic cover off
the flat Cell (a battery should really have more than one cell) will drag
the output of you good cell low. So I suggest that you prise the top off and
remove the flat cell. You will then see what voltage the cell and what pins
it needs to be connected to....
Post by phantomm_1
Pass them around to anyone, who knows something about these.
Just don't post them anywhere without asking me please.
I consider my snap pics, as part of my work.
Anyone who uses a Falcon or does work on chips like this and
wants to see the pics, just e-mail me and I'll e-mail them to you.
thanks,
Barry
Derryck Croker
2010-02-20 13:33:44 UTC
Permalink
Post by Dave
All the NVRAM chips I have seen are basically a RAM chip with a large
plastic cover and cell underneath.
But they aren't all like this I'm afraid. The OP might be lucky, in
which case repair is simple (a CR2302 cell in a separate holder IIRC),
or if the NVRAM chip is the more usual solid construction, then
replacement is the only option. And it's best left to someone who has
experience in this area.
--
Cheshunt Computer Club
The essential accessory for your Atari
http://ccc.atari.org
Dave
2010-02-20 20:25:26 UTC
Permalink
Post by Dave
All the NVRAM chips I have seen are basically a RAM chip with a large
plastic cover and cell underneath.
But they aren't all like this I'm afraid. The OP might be lucky, in which
case repair is simple (a CR2302 cell in a separate holder IIRC), or if the
NVRAM chip is the more usual solid construction, then replacement is the
only option. And it's best left to someone who has experience in this
area.
Yes, in that case adding an extra cell isn't any use....
--
Cheshunt Computer Club
The essential accessory for your Atari
http://ccc.atari.org
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