smoke86 wrote on 2022-09-25, 20:14:Whoa, hold your horses man!
Your motherboard does not support ANY K6-2 CPUs.
It is pretty good chance that you fried your CPU s […]
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Whoa, hold your horses man!
Your motherboard does not support ANY K6-2 CPUs.
It is pretty good chance that you fried your CPU since you did not mention tinkering with voltage - related jumpers.
If motherboard works OK with supported CPU - leave the BIOS alone.
Anyway, that may be OTP chip (one time programmable), and if you try to erase it - it's gone forever.
hey cmon, I am on it for a full day today, and if you search a little you can find who did it.
"The Skinned Knuckles Workshop
HITSTATS By
If you have a VX-Pro+ based motherboard you may find the information posted here of interest.
They explain how I've managed to get an AMD K6/266 working on my VX-Pro+ motherboard, overclocked to 337Mhz.
-And-
How I have subsequently upgraded my CPU to a K6-2/350, running at 412Mhz.
Email reports of 450, 500Mhz and K6-3/400 operational!!!!
"
Why ?
I had been running my VX-Pro board with an SGS manufactured Cyrix 6x86 PR166 and whilst this was providing a reasonable turn of speed I felt that there was room for improvement so I considered that;
My motherboard could only support processors upto 233Mhz (with the official 66Mhz front side bus)
The Intel processor supplies are running out (Intel now having stopped production)
Cyrix processors get poor reviews in terms of FPU performance
AMD K6 and K6-2 have a good reputation for performance (FPU not as good as Intel, but 2nd best)
IDT Winchips would be an unknown quatity in my motherboard and probably wouldn't give the 'rounded' performance required
After thinking about things for a while, I decided that a K6 or K6-2 would be the 'best bet'. In terms of which processor speed to choose, well I thought that as my system could officially run to 233 and with a 75Mhz FSB a processor could do 266, and near 300 with 83Mhz FSB I thought that a rating of 266 would be preferable. By doing so I wasn't paying the price premium for a 300Mhz part and would limit my over-investment if I really could only run at 233.
The next decision was as to a straight K6 or a K6-2 with the 3D support.
Pricing for the different chips was not significant, there was about a £15 premium for the K6-2 per clock speed.
I contacted a couple of suppliers and visited the WWW technical posts to gauge opinion, at that time most people and both suppliers said that "motherboard support" was required for the 3D support. So I went for a straight K6 at 266 Mhz.
** I now understand that, although motherboard support will enable a K6-2 to be identified and reported as such, the words of wisdom now seem to say that; If your motherboard will report a straight K6 (and hence configure the board to set the cache write enable etc) then it will also configure a K6-2 correctly - 3D support is in application software NOT the motherboard.
Too late for this time, but maybe next...
top
Core voltages
Anyway, Having plugged my new chip into the motherboard I came across my first problem - Voltage levels.
The K6, model6 (upto 233) was fabricated on the 0.35 micron facility and ran at a higher voltage than the K6 model7 (266/300) and K6-2 which are made on the 0.25 fab and run at 2.2V in the core.
My VX-Pro board has a lowest voltage setting of 2.5V - meaning, return to supplier, restocking fee etc.....arrrggggghhhhhh.
So,
At first I was using the chip at 2.5V core (the lowest the board will go to) with an overclocked bus speed of 75Mhz and a (default) 1.5/3.5 multiplier to give a 266 performance, the chip remained fairly cool with a top case temp of around 33 degrees ‘C’.
Bios
The main problem was one of 'cosmetics'- the BIOS didn't recognise the new chip. At bootup it just displayed that it found "-MMX CPU 66Mhz", it certainly appeared much faster than my previous Cyrix PR166 but I suspected that the internal CPU registers were not set for a K6. I scouted around on the 'net for some help and found a handfull of 'optimiser' programs that would correctly set the CPU for optimum performance but I still had doubts, at about the same time a new BIOS file for my motherboard was posted but with almost no details as to the enhanced capability - I emailed PCChips for confirmation of the K6 Model7 identification but as you might expect I got no reply!
The 'new' BIOS date is 4/30/1998S and the markings for my bios chip (which is 12V) was not listed on the PCChips Website either. The files were still available on the Taiwan PCChips website as of late October 1998.
So with nothing to loose but a cheap motherboard - I 'flashed' the Bios, which was completely painless and very quick! It solved the problem - I now had a correct BIOS identification of the K6 chip, mind you I still don't know if it would identify a K6-2 (or 3 for that matter) has anyone tried it?
Having tried altering the jumpers to give 3.5x66Mhz -233 and 3.5x75Mhz -266 and having the system stable like this for a little while, I thought I'd really like to get more speed out of this chip!
This is what I cannot do. Upload bios. I dont'really don't know why my motherboard can't erase the bios.
Computer lover since 1992.
Love retro-computing, retro-gaming, high-end systems and all about computer-tech.
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