[RndTbl] Need help with serial connection

Adam Thompson athompso at athompso.net
Fri May 27 14:08:29 CDT 2011


Unless Sun radically changed their approach since I last worked with current great, the LOM port won't support flow control at all.  By definition, software flow control is handled by whatever is processing your input, so either the LOM f/w or the Solaris tty layer.
The serial port on the host itself (i.e. /dev/cua0) does support h/w flow control, and would normally be set to 115.2kbps if you're doing a lot of work there anyway.
That's one of the rationales to leaving console ports at 9600, no flow control: everything can handle that without buffer overflows, you only need a 3-wire serial cable, and it's transparent to ^Q/^S in case that's important (or in case the connected device handles it, as in UNIX, printers, Cisco IOS, etc.).
-Adam


JohnD <jd at westman.wave.ca> wrote:

>
>Thirded on screen.
>
>But if you do a lot of binary xfer, the hw flow control may be worth a bit more patience.
>And you can then use Ctrl_S (xoff**) and Ctrl_Q a bit more freely (e.g: scrollstop -vs- /usr/bin/less; since you're only extruding at 9600), and yer scroll 
>states won't get obfuskomacated.
>
>Check BIOS/CMOS settings on both machines, for mbrd's integrated UART/ComN (toggles).
>Old IBM defaults for primary&secondary were irq4:3F8 and irq3:3E8
>
>Check PSU for negative12v on psuPin12 (usu.blue) -vs- adjacent psuPin13 (black:grnd)
>
>In rs232 terms, the DSR+[D]CD (usu.combined) & CTS signals minicom wants to see asserted from the OtherEnd, ain't.
>
>Since MrCyan's prolly a NullMdm/CrossoverCable, ThisEnd's handshakes*** are actually coming from OtherEnd's DTR or RTS pins, resp.
>You may think MrCyan is weird, but that MrMagenta is a downright reservoir dog.
>
>Curious my ageing brain still responds to AT&F, but I can't juggle this newfangled capex or optex without fumbling the PON
>
>John Donovan
>planet Brandon
>
>** pardon my language
>
>*** speaking of language, would the modern vernacular now be 'Data Daps' ?
>
>In which case, then let us lower our respective altitudes and engage in pheremonally fragrant activities on the dancefloor
>(transl: 'Get down, get funky.')
>
>_ _ _ _ _ _ _ _ _ _ _
>
>On ImpossibleDate(01/-10/-28163) 01:59 PM, Kevin McGregor wrote:
>> This is driving me nuts, since it was working and now it isn't and I have no idea what has changed. I hope someone can help.
>>
>> I have a SunFire V490 at work. I also have a HP ProLiant server in the same rack, which is running Ubuntu Server 10.04. I've got the weird cyan serial 
>> cable plugged in to the lone serial port on the ProLiant and the other end plugged into the V490 port ("SERIAL"). I've got minicom running on the Linux 
>> box configured for 9600, 8N1 on /dev/ttyS0. minicom's status line reports "OFFLINE", and I get no response to any keyboard input.
>>
>> What's wrong? I can freely power off/on the SunFire and anything else I want to do with it. I have the keys for the front panel, too. Do I have to switch 
>> it to diagnostics mode or something? We had it working before, and it was quite easy.
>>
>> Help!
>>
>> Kevin
>
>
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