Outline for May 16, 2008
, §6, 7, 10
Greetings and felicitations!
continued from last lecture
Goals; what should a good process/device interface do?
Device hardware; what does a device look like?
Device interface; how are the devices connected to the computer?
Device drivers; what do the kernel modules interacting with devices look like?
Process interface; how do the processes access devices?
Character code independence
Uniform treatment of devices
Disks: platters, tracks, cylinders, sectors, heads, arms; seek, rotational, and transfer latencies
Drums: one head per track; use
Magnetic tapes: nine-track tapes, frames, tape density, records, inter-record gaps, labels, headers, trailers; winding, transfer latencies
Communication lines: simplex, half-duplex, full duplex; baud; protocols; bit stuffing, character stuffing (escapes)
Device registers, controllers
Channels, commands, channel programs
Command chaining, data chaining (scatter-gather)
Selector, multiplier channels
Standard interface; upper, lower part
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Version of May 27, 2008 at 8:18 PM