Octane won't boot after failed PROM upgrade. Any suggestions?
Benjamin Döpke
my Octane lost power while "/usr/sbin/flash" was running.
Now, it won't boot anymore. Just a blank screen, White led on the front
panel, two characters garbage on the serial console. Well. I'd guess,
the PROM has been corrupted. And if I'd do that, i'd think that this would
not be my day...
Does anybody here have a clue how I can get my system back into
a working state without replacing my whole IP30? It's a 030-0887-005
Rev.A and I wouldn't feel too delighted if I had to replace a unit
that is in perfect state, just because the Flash doesn't contain
a valid PROM.
I __think__ I identified the PROM already. There's a Sharp
LH28F800SUT-70 (U12) next to the dip-40 socket, wich seems to be a
512kx16Bit eeprom, so it's size would fit.
Is this the PROM? Can anybody confirm that?
Perhaps, someone can point me to a datasheet for that chip? I couldn't
find one... (I didn't google much)
Does anybody know what the 40 pin socket (U10) is all about? And the
"select flash prom" jumper? I don't know of any 512kx16Bit eeprom that
would fit on a dip-40, so -- what is it used for? Is it used for
anything? ISP perhaps? If not, why has it been soldered there?
My last resort would be to find some SMD wizzard to unmount the
chip, put it in a burner, write a proper prom on it, and solder
it back...
but that would be hmmm.. well.. quite invasive. I wouldn't bee too happy
with that.
Any advice? Condolences? Suggestions? Conspiracy Theories, anyone?
Everything would be appreciated...
Benjamin
Wolfgang Szoecs
be...@web.de (Benjamin Döpke) writes:
> Does anybody know what the 40 pin socket (U10) is all about? And the
> "select flash prom" jumper? I don't know of any 512kx16Bit eeprom that
> would fit on a dip-40, so -- what is it used for? Is it used for
> anything? ISP perhaps? If not, why has it been soldered there?
the jumper is for selecting whether the machine should use
the builtin PROM or the emulated PROM provided through that socket.
Normally, you plug into the socket a PROM-ICE (ice=in-circuit-emulator)
for development purposes.
Wolfgang
Benjamin Döpke
Thank's a lot for that hint!
As this connector is directly connected to the LH28F800SUT, it is
apparent to me that that the LH28F800SUT is the PROM.
According to the datasheet of a device similar to the LH28F800SUT,
I managed to get almost the complete pinout of this connector using
a simple ohm-meter:
+--------------+
Vcc | 1 \/ 40| Vcc
| 2 39| A18
DQ15 | 3 38| A17
DQ14 | 4 37| A16
DQ13 | 5 36| A15
DQ12 | 6 35| A14
DQ11 | 7 34| A13
DQ10 | 8 33| A12
DQ9 | 9 32| A11
DQ8 |10 U10 31| A10
GND |11 30| GND
DQ7 |12 29| A9
DQ6 |13 28| A8
DQ5 |14 27| A7
DQ4 |15 26| A6
DQ3 |16 25| A5
DQ2 |17 24| A4
DQ1 |18 23| A3
DQ0 |19 22| A2
#OE |20 21| A1
+--------------+
The only problems that remain to me are:
I don't have a clue what pin 2 of U10 is connected to (it is
not connected to any of the pins of the LH28F800SUT), and that
pin A0 of the LH28F800SUT is not connected to any of the pins
of U10.
Either pin 2 of U10 is mapped to A0 in some form, or the
simulated rom will only have 512k, so no Octane PROM
published by SGI would fit on it. (that would be bad)
Does the signalling of the DQ* pins on U10 occur in 3.3V or in
5V?
Can I boot my machine using this connector and Grammar Engine
Inc. PromICE, switch over to the 28F800SUT while the machine is
powered up and flash it with a new PROM? Would that be possible?
Thanks,
Benjamin
Wolfgang Szoecs
yes --- should be possible, as this is also the way how
we bring up new machines ...
OTOH, the 'oldest' machine I have practical experience with
(read: set up and used the PromICE myself) - is the Fuel.
So I have no idea what exactly the PromICE's jumper-settings etc. need to be
for the Octane ... - even the cable for the motherboard is different ...
(and I don't own or saw the correct adapter cable for an Octane)
But your basic idea how to recover the machine is correct.
hook up the PromICE - load a new PROM into it - boot the machine,
and once it's up - pull the jumper - and flash the PROM.
Disclaimer:
This message contains lots of destructive ideas to your hardware.
So whatever you do inspired by this mail - you do it on your own risk.
This is my PERSONAL opinion ONLY.
Wolfgang
Benjamin Döpke
> OTOH, the 'oldest' machine I have practical experience with
> (read: set up and used the PromICE myself) - is the Fuel.
>
> So I have no idea what exactly the PromICE's jumper-settings etc. need to be
> for the Octane ... - even the cable for the motherboard is different ...
> (and I don't own or saw the correct adapter cable for an Octane)
I propably found the correct adapter cable:
http://www.promice.com/TargetCables/pdf/DIP40.pdf
It is identical to the pinout I measured already, and
"Chip Enable" is connected to Pin 2. That sounds reasonable.
But, using this cable, the simulated PROM can only be 512K in
size! I'm not sure where to get a PROM image for an Octane that
is smaller than 800K. Duh. Perhaps that was just the reason to
change the adapter cable for the Fuel...
Signalling Voltage is still unknown... but that can be found out.
512k PROM size is where i'm really stuck right now. Maybe, older
PROMs are smaller? I found none so far.
By the way... the serial console is not completely dead. My
Null-Modem cable was just broken. It says:
FPROM Invalid, Starting Recovery
flash_io is too big for bss_flash_io, reloc_size
And a register dump follows.
"Starting Recovery" sounds interesting...
Benjamin