What are three common problems that can lead to a printer losing data on the IP2?
There are three common problems that can lead to a printer losing data: (1) Flow control improperly configured. In this case a short print job may appear to lose data only at the end, and a very short one may not lose data at all. A sufficiently long job will lose data throughout the report, not just at the end. (2) Port-close flushing. Under Unix, when a port is closed, the OS does not expect to wait indefinitely for data to drain. It asks the driver to “resume” sending that may have been stopped by flow control, and afterward to “flush” any remaining output. This is how serial ports work as a matter of design; it is not driver-specific. Because of this, it is common for spooling scripts to include the command “drain_output” (I think it is called). This command performs a certain ioctl() on the standard output, the effect of which is to wait _INDEFINITELY_ for output to drain, before continuing. This is typically the last command in the script, so by the time the script exits (and the
