- Reverse-engineering the ModR/M addressing microcode in the Intel 8086 processor (righto.com)
One interesting aspect of a computer’s instruction set is its addressing modes, how the computer determines the address for a memory access. The Intel 8086 (1978) used the ModR/M byte, a special byte following the opcode, to select the addressing mode.1 The ModR/M byte has persisted into the modern x86 architecture, so it’s interesting to look at its roots and original implementation.
- Ara (constellation) (Wikipedia)
Ara (Latin for “the Altar”) is a southern constellation between Scorpius, Telescopium, Triangulum Australe, and Norma. It was (as Βωμός, Bōmǒs) one of the Greek bulk (namely 48) described by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations designated by the International Astronomical Union.