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C80287XL Math Co-Procesor for 286 motherboards

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barney

Experienced Member
Joined
Oct 19, 2009
Messages
202
Location
Tampa, FL
I'm selling "C80287XL Math Co-Processors" for 286 motherboards. This particular model is the best Math Co-Processor made for the 286. It's able to automatically match the speed of whatever 286 processor you throw at it. It's a 40 Pin Ceramic DIP and is in good working condition. Don't leave that Math Co-Processor socket empty on your motherboard - Soup your system to the max and install one of these.

Info on this Processor at this link: http://en.wikipedia.org/wiki/File:KL_Intel_i80287XL_Big_Markings.jpg


I'm selling them for $15 each plus $5 shipping.
I have 6 for sale.
Email if your interrested.

Thanks.
 
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I have a Harris 80286-16.

I think that 80287 FPUs ideally run @ 1/2 to 2/3 of the CPU speed so an 80287-10 would be a good fit for an 80286-16 or an 80286-20.
 
The 287XL works at up to 12 MHz, as far as I know.

The 287XL runs at 1/2 the clock speed if pin 39 is pulled low, where the standard 287 will only run at 1/3 the clock speed if the same pin is pulled low. If the pin is high, then both runs at 1/1 the clock speed.

The main difference is that the 287XL is a 387SX in disguise. Programs will therefore see and treat it as a 387 instead of a 287. Another thing to note is that it is to a larger extent asynchronous to the 286, and will not monitor the execution of ESCAPE instructions as a regular 287 would.
 
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Hey Barney! Have you tried putting one of these in your Wang? If so, did it work? I'm asking because I put an IIT 2C87 (rated for 20 MHz) in mine and it has problems when running at 16 MHz. At 8 MHz it works just fine though. I don't know what the problem is. :confused:
 
Yes, I did. It's on my Wang and running beautifully. Best damn chip I ever used before.

Barney
 
If anybody is still interrested, I still have 2 or 3 more of these Math Co-processors I'm selling. PM me if your interrested. Thanks.

Barney
 
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