Talk:Serial adapters: Difference between revisions
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PeasthopeOld (talk | contribs) (→Open Firmware: Further clarification about lack of clarity. =8~)) |
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== Back to back == |
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(the discussion about the back to back connection method has been moved to [[Talk:Firmware/Serial_Terminal]]). |
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The section entitled "Open Firmware" refers to two XOs with serial ports connected directly? Serial adapters are not used? Wouldn't hurt to mention this. The crossover cable requires two J1 CN24 female connectors and a cable with at least 3 conductors. Connectors available from retail vendors are mentioned in the later section "XO Serial Ports - physical interface". Regards, [[User:Peasthope|Peasthope]] 18:05, 18 August 2012 (UTC) |
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== Reassembling the system == |
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:Thanks. Yes, USB serial adapters are not needed, and won't help, in the XO to XO configuration, but this is not Open Firmware specific, the same can be done with Linux. No, a crossover cable does not require two connectors, it could be fabricated in several ways, depending on what is available. J1 and CN24 are a model-specific identifier, so I would not mention them in the context of software. --[[User:Quozl|Quozl]] 23:05, 20 August 2012 (UTC) |
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Regarding "Reassembling the system", I wonder whether there is space to cut an opening in the case so that the RS-232 connector or USB Type B connector can be mounted flush. Various photographs suggest this possibility and the arrangement would be far better than leaving the adapter dangling by the wires. Without detailed drawings or trying it on real hardware, we can not be sure about fitting. The different versions of XO and of serial adapter complicate further. Regards, ... [[User:Peasthope|Peasthope]] 22:44, 17 March 2013 (UTC) |
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> No, a crossover cable does not require two connectors, ... |
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:Thanks. We do not do that because the number of laptops in our lab usually exceeds the number of serial adapters by several orders of magnitude, the time spent would be wasted once the laptop is no longer to be accessed via serial, and the mechanical stress would move from the cheap four strand cable to the more expensive USB B plug and serial adapter assembly. If you have only one XO and one serial adapter, try some gaffer tape. Place the serial adapter behind the microphone or the camera, depending on which side the 3.3V serial cable exits. --[[User:Quozl|Quozl]] 21:15, 18 March 2013 (UTC). |
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Do you visualize soldering wires directly to the UART? I'd rather make a crossover cable with a connector on each end to plug into Jn on the board; whatever n is for the model in question. |
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> J1 and CN24 are a model-specific identifier, so I would not mention them in the context of software. |
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Agreed but a crossover cable is hardware and the software won't work without it and the present description is better but still unclear. What about discussing the crossover connection under "Connecting up" rather than under "Open Firmware". |
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> ... the same can be done with Linux. |
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Typically using an RS232 crossover cable to connect serial ports on two machines. A serial connection directly to a system board would be somewhat unusual. Possible but you'd want to be sure about voltage levels. When connectors are available, as on the XO, they should be used. |
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> [table] A crossover cable consists of the following:<br> |
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> host pin (cable colour) target pin (cable colour) purpose<br> |
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> GND (orange) ...<br> |
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Where do you see these colors? Not on the system board. On the serial adapter? But the premise is that we are not using serial adapters. Shouldn't the table refer to something visible such as conductor numbers in http://wiki.laptop.org/go/File:Closeup-J1.png? Regards, ... [[User:Peasthope|Peasthope]] 01:44, 24 August 2012 (UTC) |
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Latest revision as of 22:06, 18 March 2013
Back to back
(the discussion about the back to back connection method has been moved to Talk:Firmware/Serial_Terminal).
Reassembling the system
Regarding "Reassembling the system", I wonder whether there is space to cut an opening in the case so that the RS-232 connector or USB Type B connector can be mounted flush. Various photographs suggest this possibility and the arrangement would be far better than leaving the adapter dangling by the wires. Without detailed drawings or trying it on real hardware, we can not be sure about fitting. The different versions of XO and of serial adapter complicate further. Regards, ... Peasthope 22:44, 17 March 2013 (UTC)
- Thanks. We do not do that because the number of laptops in our lab usually exceeds the number of serial adapters by several orders of magnitude, the time spent would be wasted once the laptop is no longer to be accessed via serial, and the mechanical stress would move from the cheap four strand cable to the more expensive USB B plug and serial adapter assembly. If you have only one XO and one serial adapter, try some gaffer tape. Place the serial adapter behind the microphone or the camera, depending on which side the 3.3V serial cable exits. --Quozl 21:15, 18 March 2013 (UTC).