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On 6/23/06, 张|武 <zhangweiwu@××××××.com> wrote: |
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>Another small question I hope someone with professional knowledge can |
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>help. I was told ECP/bidirectional printer cable can handle 2Mbps data |
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>transfer, that seems to be suggesting using parallel cable is as good as |
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>using USB1 cable (as USB1 is supposed to handle 1.2Mbps ony), or even |
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>better. Is it true? |
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Low speed devices like mouse, keyboard uses 1.5Mbps, printer should use |
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12Mbps on USB 1.1. Definitely better than ECP... |
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On 6/23/06, 张|武 <zhangweiwu@××××××.com> wrote: |
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> |
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> This is really making me puzzle: |
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> sappho ~ # lspci | grep USB |
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> 0000:02:02.0 USB Controller: NEC Corporation USB (rev 41) |
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> 0000:02:02.1 USB Controller: NEC Corporation USB (rev 41) |
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> 0000:02:02.2 USB Controller: NEC Corporation USB 2.0 (rev 02) |
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Use lspci -v | grep USB, that should give you also information if it's |
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OHCI, UHCI or EHCI (there are 3 standards, not only two). OHCI is |
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1.1EHCI/UHCI is two different standards for |
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2.0, depends on hardware vendor. |
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When the kernel boots it shows me that only ohci device is discovered, |
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> someone suggested that ohci only support USB 1.x. Now lspci shows the |
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> card has "USB 2.0". I don't understand, does it work in the way that the |
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> card either work in 2.0 mode with one device, or USB 1.0 with two |
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> separate devices? |
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> |
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> What if I remove OCHI and add back only UHCI driver in the kernel? |
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You can leave both enabled in the kernel. OHCI will be used if you connect |
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1.1 device, EHCI/UHCI (depends on which you discover with lspci -v) will be |
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used with 2.0 devices. |
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Caster |
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