Hello, I am new to the forum, I have two ibm 2133 computers and I want to expand to a dx2, I soldered the b14 cable to ground where the screw to the chassis and the update does not work, please could you send me a photo of how the cable is soldered, thank you very much

kobytos87 wrote on 2023-08-14, 08:21:

Hello, I am new to the forum, I have two ibm 2133 computers and I want to expand to a dx2, I soldered the b14 cable to ground where the screw to the chassis and the update does not work, please could you send me a photo of how the cable is soldered, thank you very much

You may have to also disable the onboard cpu by removing it, or lifting leg and pulling flt to gnd

If I were designing these boards I would have ran flt to vss with a resistor and also to a floating ground leg on the “487” socket so that when a 487 was installed it would pull primary flt pin to gnd overriding the pull up resistor. Causing the “487” to take full control of the system bus. But b14 should have done this in a similar way I thought. Which makes sense, intel didn’t want 486 cpus to be able to be used as 487 cpus.

Anyway, try lifting the flt leg on the onboard 486 if soldered and pull it to gnd.
If socketed, just remove it.