Tag Archives: Architecture

Humor, Science, Technology, Work

My Internal IRQ is Broken

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Interrupt ReQuest (IRQ) is an hardware interrupt on a PC. There are 16 IRQ lines used to signal the CPU that a peripheral event has started or terminated. Except for PCI devices, two devices cannot use the same line. If a new expansion card is preset to the IRQ used by an existing board, one of them must be changed. This was an enormous headache in earlier machines.

Starting with the Intel 286 CPU in 1982, two 8259A controller chips were cascaded together and bumped the IRQs from 8 to 16. However, IRQ 2 is lost because it is used to connect to the second chip. IRQ 9 may be available for general use as most VGA cards do not require an IRQ.

PCI to the Rescue
The PCI bus solved the limited IRQ problem, as it allowed IRQs to be shared. For example, if there were only one IRQ left after ISA devices were assigned their required IRQs, all PCI devices could share it.

Business, Science, Technology

Companies’ Fiber Infra Perform Quantum Computing Prior to Cloud, Elastic Computing Hub

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A Qubit, a base unit in Quantum computing, representing several states simultaneously, as opposed to a bit, on or off, two states, got me thinking based on the New York Times article on the Australians developing a new class of Quantum Computer, plus the article on Google’s Fiber Project, and my conversation with a Verizon FiOS engineer regarding their experimentation with alternate [color] light and their fiber applications got me thinking:
– The delivery system itself would process data, in addition to the EC hub, similar to the human nervous system.
– The alternating colors / frequencies represent multiple ‘applications’ overlapped within the fiber, and could provide the ability to throttle frequencies?

Note: However, Optical cables transfer data at the speed of light in glass (slower than vacuum). This is typically around 180,000 to 200,000 km/s, resulting in 5.0 to 5.5 microseconds of latency per km.

Cable Companies’ Fiber Gives an Expanded Scope to Cloud, Elastic Computing.  Leased lines may form a whole new battleground of opportunity, or at least reignite the battle for those familiar with the break up of the “Baby Bells”.