BIOS in NVRAM?

Only for programmers and BIOS gurus with technical questions.
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PeteV
BIOS Rookie
Posts: 51
Joined: Wed Apr 07, 2004 8:22 am

Sun May 23, 2004 1:18 am

Hi!

After notising the fact described on the later post of mine 15 Jun 2004, I had to re-write/edit this first post for this topic as follows:

During my investigations on the AT/S7/PI mobos', I suddenly run into a case, on which I assumed, that the BIOS code was constantly loaded on and at boot-up read from some kind of NVRAM on the mobo, as the BIOS chip on a DIP32 socket on the board proved to be not in use at all, i.e. it's completely useless/idle and like "forgotten" there ... Can this be true? Yes, I first assumed, and later on did notise, that there was actually another PLCC32 BIOS chip soldered onto the mobo!

On all the some 9 other AT/S7/PI-cases, which I have been going through, the BIOS is loaded at boot-up every time from the replaceable BIOS chip, which is noted by the fact, that the boot-up will be freezing totally at the very beginning, if no BIOS chip is present on the socket, but not on this particular case.

This Fujitsu-Siemens (former ICL/Nokia) Ergo x451 AT/S7/PI/166 mobo with OPTi55xM chipset and SMC FDC3/C665GT MultiIO chip was somehow strangely different, it didn't need it's DIP32 BIOS chip at all and did boot-up well even without it. This was suprising me much and also did confuse me quite much for a while when testing and did "renew" my knowledge on the BIOS techniques on the AT/S7/PI mobos' ... Maybe this is a mobo from the times in 1996 just changing the techniques to a newer one, and the old tehnique was "forgotten" on the mobo ...

On the newer boards, those with replaceable or permanently soldered PLCC32 and TSOP32 BIOS chips, I have been notising this NVRAM type of technique in use, but have not yet been investigating it too deeply, just doing maybe some 30 update flashes, luckily all succeeding, huh-huh!,
knowing, that the flashing of these might be more dangerous and become much more expensive when failing, than the old replaceable DIP32 BIOS flashes ...

Please freely comment, if there is anything I may have not been notising on this case.


Best regards,

Pete V.
Last edited by PeteV on Thu Jul 01, 2004 5:30 pm, edited 1 time in total.
PeteV
BIOS Rookie
Posts: 51
Joined: Wed Apr 07, 2004 8:22 am

Sat Jun 05, 2004 3:38 pm

Hi!

Please, I'm still eagerly waiting for some/any reply of this topic of mine:
PeteV wrote: So, as a summary, please correct me, if not having right, the
NVRAM BIOS technique is something like

1. the on board NVRAM BIOS is flashed, as usual, for the first time
at the mobo manufacturer, and later on flashed, when needing update
or in case of a sudden failure/loss, with a special .exe or other
single file from a diskette on a separate boot-up by a technician
at the user site or at a service workshop

2. the BIOS code is loaded at boot-up directly from the NVRAM instead
of any separate replaceable or on board soldered BIOS chip

But, still there is some questions in the air, i.e.

- where the NVRAM actually is located?
- when clearing CMOS with the jumper, what does it actually clear
and where, the CMOS, the RTC, the NVRAM, or ...?
- what are the actual real roles of all these very essential
components, on the older and the newer mobos'?
- have the BIOS/CMOS/RTC etc. nowadays been somehow "smelted"
together to some multifunction entirety?
Regards,

Pete V.
PeteV
BIOS Rookie
Posts: 51
Joined: Wed Apr 07, 2004 8:22 am

Tue Jun 15, 2004 1:11 pm

Hi!

Sorry, pals!

After a more thorough look into this Fujitsu-Siemens/ICL Ergo x451 AT/S7/PI mobo I suddenly found, under a full-covering white label sticker ..., besides and close to the "useless" DIP32 BIOS connector, another soldered-in PLCC32 BIOS chip, which is the answer to all this mystery ...

But, why this dual BIOS chip design, with the DIP32 with no role, or may it be used/needed for something?

I may come back to this topic with renewing all the original message text according to the new knowledge status.

Best regards,

Pete V.
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