I'm hoping someone can help with some memory and cpu upgrade questions. My FIC PA-2006 M/B has the original Cyrix 6x86 P200+ CPU on it, and two 64MB EDO ECC unb 3.3v DIMMs.  
 
First, I'd like to upgrade the memory. Although there are two empty 72 pin SIMM sockets, I've read that it's not a good idea to mix DIMMs & SIMMs, especially if one is 3.3v and the other is 5v, so I was thinking of replacing the DIMMs with two Kingston 256MB PC133/ 133MHz SDRAM DIMMs, 16MX8 Chip Configuration,168 Pin, 3.3V, 7.5 ns, CAS LATENCY (CL 3), Non ECC, Non REGISTERED - (eBay item 160168779666, http://cgi.ebay.com/ws/eBayISAPI.d [...] T&ih=006). Do you think this will work?
 
Also, the FIC manual says there's a max of 384MB using two 128MB SIMMs + two 64MB DIMMs, but it has asterisks next to those sizes and states that this size memory wasn't available when the manual was printed. Is it likely that 512MB will work? Will I need to upgrade the BIOS? (I have the original BIOS).
 
Regarding the CPU, I'd like to replace the socket 7 Cyrix with an AMD K6 -- maybe a III/450 or K6-III+/450 if they'll work with the FSB set at the max (75MHz) -- but I'm not sure how to set the freq ratio to 1.5x for a K6. The CPU to Bus Frequency Ratio FREQ1 and FREQ2 jumpers in the PA-2006 manual from the FIC website shows both jumpers set to the left equals either 1.5x for a K5 or 3.5x for a K6. Is that because the K6 interprets 1.5x as 3.5x? What's the type and speed of the fastest K6 that this M/B can run properly and that you would recommend? The M/B has already has split voltages, so I'm hoping that I won't need a PowerLeap upgrade adapter.  
 
Thanks for your help.

It may only read up to 128 or 256 megs of the memory stick. If I were you, I would look at the faqs on changing motherboards, and start over with a new board-cpu-heatsink that uses ddr2. If your case and power supply are getting too old to use new components in, I would wait for black friday and get a new pc for $199. Best buy and Fry's always have at least one up for sale. You can even download the hardrive manufacturer's software and make an exact copy of your old hardrive or move it over to the new pc and use it as a spare.

Thanks for the reply, o1die. Finances won't allow me to upgrade the computer right now: all my ISA boards and many software apps & drivers would have to be replaced, not to mention the cost of sufficient memory and a cpu to run today's "pigware". I managed to get some P133 memory for $19/256MB; now I'm working on upgrading the CPU.
 
Does anyone out there help upgrading the CPU? I'd like to replace the socket 7 Cyrix with an AMD K6-III+/450 with the FSB set at 75MHz and the freq ratio to 2 (which I've read the K6-III+ will interpret as x6).
 
Is there a way to jumper in a resistor to obtain the 2.0 volt core voltage for this chip? If not, how about if I use a series silicon diode or two (to drop 0.65v each) on the output of the core voltage regulator? I'd rather find a way that didn't involve soldering on the motherboard, such as jumpering in a resistor, though. I was able to obtain a chart of pa-2007 core voltage resistors, but not for my pa-2006; are they the same (except for 11-12/2.1v, which mine doesn't have)?
 
R268 61.9k ohms 3.52v VRE 1-2  
R269 75.0k ohms 3.28v STD 3-4  
R272 90.0k ohms 3.2v 5-6  
R274 158k ohms 2.9v 7-8  
R277 210k ohms 2.8v 9-10  
R701 82.5k ohms 2.1v 11-12  
 
If so, could I jumper in a series resistor across 9 & 10 in order to obtain  2.1 volts?
 
Will I need to upgrade the BIOS to recognize the CPU or additional memory? (I have the original Award BIOS v4.51PG version 6.15J903 that came with the pa-2006). If so, which version will I need?  
 
Thanks for your help.