QQ Happens: 12月 2009

2009年12月20日星期日

音樂型態

1. Slow Soul / 8 Beat

2. Soul / 16 Beat

3. Folk Rock

4. Slow Rock

5. Waltz

6. 跑馬式節奏

7. 三指法

8. Groove Funk 放克

9. Bossa Nova

10. 十二小節式的藍調伴奏模式

音階(Scale)
依照音名,由低至高, 或由高至低。

音程(Intervals)
兩個音結合一起發出聲音的兩音距離(單位為度)。
大調音階的音程：全全半全全全半
小調音階的音程：全半全全半全全

和弦
1. 以某一音為和弦主音(Root), ie. C
2. 加上比主音高3度的音(可以為大3或小3度), 稱和弦第三音, ie. (C + E or C + Eb )
3. 加上比主音高5度的音(可以為增5或減5度), 稱和弦第五音, ie. (C + E or C + Eb )
4. 構成和弦的音程組成

接著推導和弦的組成
[A] 三和弦(組成音有三個)
1. 大3和弦(major)
=主音+大3度+小3度 (此小3是大3後再加上的, 與先前的高5是相同的音)
2. 小3和弦(minor)
=主音+小3度+大3度
3. 增和弦(Augment)
=主音+大3度+大3度
4. 減和弦(Diminish)
=主音+小3度+小3度

[B]七和弦
1. 大7和弦(major7)
=主音+大3度+小3度+大3度
2. 小7和弦(minor7)
=主音+小3度+大3度+小3度
3. 屬7和弦(dominant 7)
=主音+大3度+小3度+小3度

2009年12月9日星期三

USB

USB 元件簡介
分為Host Controller, Hub and Device

Host controller
Also known as the root, the root tier, or the root hub,
the host controller can be built into the motherboard of the computer

or installed as an add-in CardBus or PCI card in the computer

to gain additional ports and bandwidth.
The host controller controls all traffic on the bus and also functions as a hub.

Hub
Provides multiple ports, for attaching devices to the USB bus.
Hubs are also responsible for detecting devices that are plugged in or unplugged,
and for providing power for attached devices. Hubs are either bus-powered,
drawing power directly from the USB bus, or self-powered, drawing power from an external AC adapter.Bus-powered hubs are capable of providing 100 milliamperes (mA) of power per port for attached devices, and they can provide a maximum of four ports for devices to be plugged into. Self-powered hubs, on the other hand, typically provide 500 mA of power per port,
and they can provide more than four ports. Hubs can be stand-alone devices, or they can be integrated into other devices such as keyboards and monitors.

Device
A USB device, which is attached to the bus through a port. A USB device can be any kind of peripheral device,
such as a keyboard, mouse, game controller, printer, and so forth.
Certain USB input devices such as keyboards and mice require only 100 mA of power to function. Thus, they can be plugged into both bus-powered and self-powered hubs, in addition to being plugged directly into a root port. Other devices such as printers, scanners, storage devices, and video-conferencing cameras might require 500 mA of power to function. These kinds of devices can only be plugged into root ports or self-powered hubs. If the device requires more than 500 mA of power, it includes a wall plug provided by the vendor for power.

[Ref] http://technet.microsoft.com/en-us/library/bb457107.aspx

USB的三種速度
1. low speed: 1.5Mbps
2. full speed:12Mbps
3. high speed: 480Mbps

You will notice we have not included speed identification for High Speed mode. High speed devices will start by connecting as a full speed device (1.5k to 3.3V). Once it has been attached, it will do a high speed chirp during reset and establish a high speed connection if the hub supports it. If the device operates in high speed mode, then the pull up resistor is removed to balance the line.