From: utzoo!henry Newsgroups: hacknews Title: Sanders misalignment kludged around (?) Article-I.D.: utzoo.2876 Posted: Thu Mar 17 19:25:42 1983 Received: Thu Mar 17 19:25:42 1983 >From some observations last night, I think I know what's been causing a persistent Sanders problem: seemingly-spontaneous paper misalignment by a couple of lines, appearing at random times. It appears to happen when a new Sanders job comes ready for printing just as the previous one is finishing. This may be yet another effect of a known problem: when the daemon dies (closing /dev/sp as it goes), the software loses track of the XON/XOFF handshaking the Sanders is doing. This problem causes the foulups that happen if the printer is offline when a job arrives. I have kludged around the problem temporarily, by adding /dev/sp to the list of the things that /lib/update holds open permanently. This required a minor change to the Sanders daemon to make it refrain from trying to set the exclusive-access bit on the device. The proper fix is to stop running the Sanders via the tty driver, i.e. give it a custom driver that is smart enough to continue monitoring the XON/XOFF handshaking even when nobody has it open. That will take a bit of work; we'll see if the /lib/update kludge fixes the problem for the moment first.