Anonymous Coward wrote:

80287XL was only ever rated by intel to run up at speeds of up to 12.5MHz....but this may have been because intel itself never made 286s faster than that (AMD and Harris did). A heatsink is probably a pretty good idea though, otherwise you should get a Cyrix or IIT FPU rated for 20MHz.

Both of those can be pricey. The only ones I have seen cost me more than it did for me to put together the rest of the system. lzf70000 has a Cyrix for $85 IIRC and there's a boxed IIT on ebay now for $149.

But on the question of that extended memory.. I much do i need exactly to run windows on it> is 1400MB just enough?

Other question..

Are 531000 dips the same as 511000 dips.

the 53ers are 70ns
the 51ers are 10 ns

I'm sure the -10 on your DRAM means 100ns 😀

Markk wrote:

I had a 286 board with sipp only slots, and instead of soldering pins on some simms, I found an alternative which is a lot easier(at least for me that I don't have so good soldering skills). I had some dead 386 boards from which I desoldered the simm slots. (Not me actually, I gave them to a friend who could do that). If you have the simm slots completely intact, then it's easy to insert their pins to the sipp holes, litteraly converting the sipp to simm slots.

Great tip - I'll save this up for a future project since I have a 286 MB with SIP slots on it - I'll desolder those and solder on some simm slots off a dead 386 board. I wonder if it will work with 4MB 30 pin simms.

Well, I think it depends on the chipset of the board. If it's one of the latest 286s there's a chance that it will work with 4MB simms. I have several 12-16MHz boards and none of them do that. However I once came across a later board with sipps that had a Harris 20MHz cpu soldered on it, which is the one I was reffering to on my previous post. Unfortunately I don't remember what was the make of the chipset, and it's been almost two years that I gave it to a friend.