VOGONS


First post, by dave343

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I built a system around the AMD K5 PR100 CPU, using the following specs...

Asus TX97-E
16GB EDO Ram
40GB IDE Drive partitioned into 3x 2GB Drives
ATI 3D Rage II 4MB PCI
SB 16 2740 Card

Windows 95B is installed and running good, but... I noticed some issues with software running. MS Office apps will open fine, but when I exit them, I'll receive an error: "Illegal Operation has Occurred" and PuTTY, the Termial/SSH software, won't open new connections, you try to connect and nothing happens.
So fast forward, I thought I'd drop in a Pentium 100 CPU... and now no more errors, PuTTY works great, connects and brings up the connections OK, MS Office no longer crashes when exiting.

So what gives? Did the AMD K5 CPU's have compatibility issues?

Reply 2 of 7, by dave343

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Garrett W wrote on 2020-04-06, 14:40:

Are you sure you're giving the proper voltage to the chip? Most K5s need 3.52V instead of the 3.3V of the classic Pentiums. What you describe sounds like an unstable CPU.

You may be right, just checked... it's set to 3.4V, and.... *palm face*, the jumpers are also set to 2x50mhz FSB.... should have been 1.5x 66fsb doh!

Reply 3 of 7, by derSammler

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The K5 up to P(R)100 used the model 0 core, which had hardware bugs. So it is possible that you get this behaviour from these bugs.

Correct voltage and FSB should be fixed first, of course. 😉

http://retro-net.de/blog.html

Reply 5 of 7, by The Serpent Rider

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Most K5s need 3.52V instead of the 3.3V of the classic Pentiums.

From my experience, late AMD K5 and IDT Wihchip C6 does not require stated voltages to work stable.

Get up, come on get down with the sickness
Open up your hate, and let it flow into me

Reply 6 of 7, by appiah4

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The Serpent Rider wrote on 2020-04-07, 15:09:

Most K5s need 3.52V instead of the 3.3V of the classic Pentiums.

From my experience, late AMD K5 and IDT Wihchip C6 does not require stated voltages to work stable.

I always ran mine at 3.5V. I think the later revisions with the die shrink are fine on 3.3V but original revision silicon like the P100 the OP has require 3.5V..

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