Messages in this thread | | | Date | Mon, 11 Jul 2005 02:54:19 +0200 | From | "Brian O'Mahoney" <> | Subject | Re: [OT] SCSI Printer on AIC78XX without SCSI Terminator |
| |
First, normal (non-differential) SCSI is an OpenCollector bus design which simply wont work without a terminator and is designed to use exactly two(2) terminators, one at each end of the bus, these both provide a pull up and terminate the bus to prevent reflections. Also the longer and faster the bus the more you depend on correct termination e.g. 130 ohm - +3.3V
For much more detail, including external terminators please see
http://www.scsita.org/aboutscsi/SCSI_Termination_Tutorial.html
Second, there is usually a built in terminator in the AIC7xxx adaptor, usually enabled in the SCSI BIOS.
Also check your device for negotiable SCSI options, eg SYNC, OFFSET
Gustavo Guillermo Pérez wrote: > Hello, I was tried to use a SCSI Printer, onto a AIC78XX (old and new driver), > when driver load, it recognise the Scanner, the Printer and Panel, but may be > the copier doesn't have an internal terminator, and driver hangs forever > discovering unexistent 4th device. I do not wish to dissasemble the copier to > solder the terminator, and I never deal with SCSI HW. Kernel I was tried: > 2.6.7, 2.4.23. but I think the driver does not change from 2.6.7 to 2.6.12. > > I see the doc about this driver but I can't figure out wich of a lot options > can help to not try to discover more than 3 devices... I'll have a chance to > play with this machine the next week, then I'm taking ideas. > > aic7xxx=seltime:2 > this option wait for answer but the device 4º waits forever... > aic7xxx=no_reset > I don't.... > aic7xxx=override_term > mmmmmm > ... > > The new driver support cmdline args? > > If someone can share comment I would appreciate it > > cheers
-- mit freundlichen Grüßen, Brian.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |