A friend of mine has one of these models of 286. Recently I resurrected it from the dead for Him, blown capacitor on the 12v rail.
I thought it might be a good idea to upgrade it with a 287 FPU DIP ic. I got one from China and was getting stack underflow and Math errors.
Tried reseating it numerous times but didn't change. The reference diskette was run many times as well. Ultimately nothing worked
so removed it and assumed it was faulty and got a refund via Aliexpress.
Ordered another 2 this time just in case, but from another supplier. Tried both Yesterday and pretty much the same errors.
Does anyone here have any experience with upgrading one of these machines with a FPU? and if so, are there any jumpers that need
to be changed. I noticed there is a JP17 right next to the CPU and FPU socket. There is no information in the technical manuals about
fitting a 287 in one of these machines, so one would assume that it's just fit and run the reference diskette and all should be ok.
I believe there has to be some sort of hardware issue causing this, as I don't believe there would be 3 faulty chips sent. All are D80287-10 the same
speed as the 286.
I thought it might be a good idea to upgrade it with a 287 FPU DIP ic. I got one from China and was getting stack underflow and Math errors.
Tried reseating it numerous times but didn't change. The reference diskette was run many times as well. Ultimately nothing worked
so removed it and assumed it was faulty and got a refund via Aliexpress.
Ordered another 2 this time just in case, but from another supplier. Tried both Yesterday and pretty much the same errors.
Does anyone here have any experience with upgrading one of these machines with a FPU? and if so, are there any jumpers that need
to be changed. I noticed there is a JP17 right next to the CPU and FPU socket. There is no information in the technical manuals about
fitting a 287 in one of these machines, so one would assume that it's just fit and run the reference diskette and all should be ok.
I believe there has to be some sort of hardware issue causing this, as I don't believe there would be 3 faulty chips sent. All are D80287-10 the same
speed as the 286.