X86 Lds May 2026

She couldn’t just remove the LDS . The entire linked list traversal depended on far pointers. But she could replace it.

And somewhere in a museum, a 386 motherboard smiled, its LDS instruction still perfectly capable of crashing any program that dared to wake it. x86 lds

A decade later, she’d tell interns: “ LDS loads a pointer and destroys your data segment. Respect it. Then avoid it.” She couldn’t just remove the LDS

The offending line looked innocent:

She wrote a small C helper using memcpy to safely read the 32-bit value into a local unsigned long , then manually set DS and BX via __asm —but with interrupts disabled via _disable() . Clunky, but safe. And somewhere in a museum, a 386 motherboard

That night, Eleanor poured a whiskey and thought about LDS . Born in 1978 with the 8086, mature in the 286’s protected mode, and already a zombie on the 386—kept alive only by backward compatibility. It was the programming equivalent of a rotary phone in a smartphone world. You could still use it. But you really, really shouldn’t.