I wish colleges taught everything mentioned in this ~100-page paper for their computer architecture course. The paper talks so much about cache, OS, threads, memory controller, and how the CPU juggles in between. If you're in your 2nd or 3rd year and want to better understand computer... See more

The idea of microcode was invented by Maurice Wilkes, a great pioneer who arguably made the earliest programmable computer — the EDSAC (pace Manchester Baby). The idea depends partly on the existence of a “large enough” memory that is much faster (3–10 times) than the 1st level RAM of the computer.

A milestone happened when the fast memory for... See more

The Alto was fabulously efficient because its approach to how its real CPU (the microcode engine) interacted with the available memory bandwidth (including the use of multiple program counters for zero overhead low-level task switching and avoiding interrupts).

Whereas the commercial CPU architectures had very poor notions of how to use memory and... See more

A very different way to look at it might be to say: well, we really want zillions of concurrent and safe processes with very fast intermessaging programmed at the highest levels — what kind of architecture would facilitate that? We certainly don’t want either “interrupts” or long latency process switching (that seems crazy to “old Parc people”. We... See more

In the early days computers were much simpler. The var-ious components of a system, such as the CPU, memory, mass storage, and network interfaces, were developed to-gether and, as a result, were quite balanced in their per-formance. For example, the memory and network inter-faces were not (much) faster than the CPU at providing data