[Rack] [Noisebridge-discuss] minotaur is down

Jonathan Lassoff jof at thejof.com
Sun Jul 7 19:05:58 UTC 2013


On Sun, Jul 7, 2013 at 11:59 AM, Henner Zeller <h.zeller at acm.org> wrote:
> On 6 July 2013 02:26, Jonathan Lassoff <jof at thejof.com> wrote:
>>
>> First, gateman needs to come up.
>>
>> I'm stuck interacting with the parallel port as a parallel port :(
>>
>> open("/dev/usb/lp0", O_RDWR)            = 3
>> ioctl(3, PPCLAIM, 0x7fff85442ba8)       = -1 ENOTTY (Inappropriate
>> ioctl for device)
>
>
> It is one of these USB -> parallel port adaptors, so might not be 100%
> compatible with a 'standard'  parallel port.
> However, writing bytes to it should still work (if I understand correctly,
> there is only one bit used to operate the buzzer ?)

Yup -- those adapters/port emulators aren't good for any bit-banging
operations that are timing-dependent.

I took the conversation onto the rack@ mailing list.

I ended up figuring out what was happening, the driver presented two
interfaces, one as the raw port and the other as a line printer. I was
using the line printer interface, and not the raw port access.
We're all good (other than the downstairs buzzer hardware being broken) now.

Cheers,
jof


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