EDO memory
This stuff is so rare nothing on the boardsort list compares
I've brought up EDO ram before.
99% of EDO ram is silver finger,
Yet thanks to an essay that is extensively referenced; that was posted on
http://www.scribd.Com titled the future of EDO (subscription required) we now have a more realistic estimate of EDO in the wild. 140-150 million EDO compatible boards.
Non working EDO sticks are since mid October averaging $10 per stick
Verified working (having some level of guarantee) are past $100 on the high end.
Intel 4000 series CPUs
As long as they have ALL pins completely and complete length sell them DOA (parts/repair) on eBay!
This set of ICs can net you $50-100 easily per chip!
That said even one damaged pin any your under $5 so if it's missing pins you're better with scrapping it. Nothing out there beyond collectors uses a dip 4XXX CPU. And as far as damaged goes it's like coins, anything under mint is only filler because you (the collector) can't afford something ms55+
Cyrix Cy6X86 CPUs
These, in general terms, don't exist and you will NEVER see an authenticated one for under a few hundred dollars.
Absolutely off the assembly line mint they run a few thousand and even damaged (missing a few pins or a few scratches on the gold cap) you can still easily pass the $100 mark.
Less than 2000 were made and around 100 made it out to the public before the line was cancelled and recalled.
A runaway error (infinity loop) in the instruction set can lead to an explosive failure do to heat.
is specific to one single chip. The cyCx86a P120GCyrix in general are low end chips.
Slocket boards
These boards were intended to let you install a socket socket CPU in a slot processor slot.
Later designs were to go from slot to the later sockets.
The range of these boards is a few dollars to well past $50 for working samples of socket to slot.
Slot to socket boards start in the low 100s!
In general order of value low to high
486/am486 to slot 1
Pentium P525-P5-66 to slot 1
486/am486 to slot a
P5 to slot a
Slot A to socket A
Slot A to socket 7XX
Slot A or Slot 1 to socket 3XX
Slot A to slot 1 (an adaptor for the board)
Slot 1 to slot A (an adaptor for the board)
These boards were in production for less than a year for AMD and less than 2 years for Intel.
Anything outside of the above list is a rare one-off (not literally one but very few)! Many companies fudged around with such socket to slot and slot to socket boards; but the rest of them are so rare you'll get a literal fortune for them; in any state of condition! And you're well beyond the general eBay market with those. Try specialist auction companies. Heritage is my favourite; even if they don't want it they will gladly point you to a reputable company, including competitors!