In Early CPUs
The HCF instruction was originally a fictitious instruction, claimed to be under development at IBM for use in their System/360 computers, along with many other amusing instructions such as, "Electrocute Computer Operator".
One apocryphal story about the HCF instruction goes back to the late 1960s, when computers used magnetic core memory. The story goes that in order to speed up the core memory on their next model the engineers increased the read/write currents in the very fine wires that were threaded through the cores. This worked fine when the computer was executing normal programs, since memory accesses were spread throughout memory. However, the HALT instruction was implemented as a "Jump to self". This meant that the same core memory location was repeatedly accessed, and the very fine wires became so hot that they started to smoke - hence the instruction was labeled "Halt and Catch Fire".
Read more about this topic: Halt And Catch Fire
Famous quotes containing the word early:
“Franklin said once in one of his inspired flights of malignity—
Early to bed and early to rise
Make a man healthy and wealth and wise.
As if it were any object to a boy to be healthy and wealthy and wise on such terms.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)