Rod, at 07:27 on Apr 20 1996, you wrote to Bill Grimsley...

BG> The really strange thing is that once jumpered to take the DX5, the bootup
BG> screen reports the chip as being an "Am5x86/P75", but then
AMI could put
BG> anything they like in their BIOS without it actually being 100% correct.

RS> Turns out its a bit tricky working out what cpu is actually installed,
RS> particularly with the more exotic ones, and the bios authors dont generally
RS> try too hard. Its all rather a can of worms, the CPUID instruction stuff 
RS> has turned into the usual abortion you always see in computing, without a 
RS> nice clean allocation of that data, particularly with the non Intel cpus.

You'd be horrified to see all the jumpers I had to set before the board
would recognise the chip as a quadrupler, and this was on a separate sheet,
not in the printed manual.  Surely the chipset and/or BIOS manufacturers
could make a board which automatically detected the CPU type and speed, a
bit like "plug and play" for CPUs.  This new board already
auto-detects the CPU voltage, which I though was rather elegant.  Pity
about the god-awful WinBIOS though.

RS> There is a crying need for something as robust as the ID stuff with IDE 
RS> drives.

Yeah, couldn't agree more, although if you don't set up the IDE parameters
in BIOS, this board will also auto-detect the drive size at boot-up, but it
does tend to add a rather noticeable delay to the boot time, as you'd
expect.

RS> Presumably they are just taking the easy way out, not attempting to keep
RS> up with the newer more exotic cpu variants and just decide its an oddy.

Dunno, the ability to use a DX5 is definitely BIOS-related here.

BG> Some of the fellows in the internet newsgroups have successfully
BG> run the DX5 with a 50MHz clock (200MHz internally) on PCI boards,

RS> I'm gunna report them to the RSPCC. You want to watch out, it is
RS> possible to kill a cpu if you get too carried away. Which can ruin
RS> the day rather more than somewhat with the more expensive cpus.

So people keep telling me, but just like unapproved modems, nobody can
actually name anybody to whom this has happened.

BG> but mine doesn't like that at all with VLB.

RS> Yeah, thats what you would expect. Do you even know that motherboard
RS> is happy with a 50MHz external speed, say with a 486DX50 ?

I'd almost bet my house that it wouldn't work.  Maybe it would with all
ISA, but not with my two VLB cards.

BG> Still, it makes you wonder just how much more they can squeeze
BG> from 486 technology.  Seems it isn't totally obsolete yet.

RS> Yeah, interesting to watch, and interesting how cheap say the 486DX2/66s 
RS> are to

I bought my original i486DX2/66 second-hand only ~2 years ago for $450, and
you can now buy one new for just $65.  Even the DX5/133 can be had for less
than $120 these days.  Pity the Pentiums haven't yet followed suit.

Regards, Bill

--- Msgedsq/2 3.20