[rescue] ID this card???

[Jeff Borisch]

s at avoidant.org wrote:

> The card came out of a sparc classic I salvaged. The classic seems to
> have a prom password. Any known way of getting around (or rid of) it? No
> boot happening now :(
>=20

Here is a good description of what to do... written by list member James
(Lockwood?) It worked for me.

Use a proper chip puller or a tool to gradually pry out the chip. Working o=
n
each end little by little. It is possible to just pull them out by hand but
it is REAL EASY to break off pins this way.

--jeffrey

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
The way you have listed (hot plugging the NVRAM) does indeed work, but it i=
s
unnecessarily risky.=A0 It's possible to reset it with no hot plugging and no
risk for the cost of a 24 pin socket (a ZIF socket if you really want to
make it easy).
=A0
Take the socket and clip off one of the address or data lines.=A0 Pin 1 is A7
and that works fine.
=A0
Remove NVRAM from motherboard.=A0 Plug the socket into the motherboard and th=
e
NVRAM chip into the socket.
=A0
Power the system on.=A0 You will get an NVRAM checksum error.=A0 At the ok
prompt, type anything that induces an NVRAM write (set-defaults works).
=A0
Power the system off.=A0 Unplug the NVRAM and socket, then plug the NVRAM bac=
k
into the motherboard.=A0 Power on and you will get another checksum error.=A0
You can now program the NVRAM to your hearts content.
=A0
It sounds more complicated, but it's really quite fast and easy as you don'=
t
have to worry about killing any hardware while the power is on.
=A0=A0
On the other hand, if you do this often you could make a "NVRAM zapper" out
of a socket, a +5V powersupply, and a switch.=A0 All you need to do is blank
one memory location and the checksum becomes invalid, this is trivial.=A0
Don't even need to worry about timing specs for the write pulse, just tap
the switch a few times and you'll program something. Total cost under $15
including the ZIF socket and the chunk of perfboard.
=A0
-James