> Hi,
>
> On Thu, 6 May 1999 10:54:21 -0700 (PDT), Dan Hollis
> <goemon@sasami.anime.net> said:
>
> >> at least on cold power-on you first have to write something to RAM
> >> to initialize the parity bit(s). if you try to read RAM first,
> >> odds are 50% that the parity bit is wrong and you'll get an NMI...
You don't really have to clear memory, i.e., write to it. All you
have to do is read all of it with NMI disabled.
Write 0x80 to port 0x70 to disable NMI, enable later by writing 0
out the same port (it's the index register for the CMOS clock-chip).
Since a read or write takes about the same time, it is usual to
just write all memory to zeros, but it is not necessary.
>
> > Are you 100% sure about this? And what about warmboots.
>
> It is necessary to initialise ECC memory, yes, but the BIOS should do it
> for you. I've only got one ECC box, but at least on that one the BIOS
> definitely spends a while setting up the memory at boot time.
>
Cheers,
Dick Johnson
***** FILE SYSTEM WAS MODIFIED *****
Penguin : Linux version 2.2.6 on an i686 machine (400.59 BogoMips).
Warning : It's hard to remain at the trailing edge of technology.
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