jbn@glacier.STANFORD.EDU (John B. Nagle) (09/11/88)
I'm losing characters between my PC and Laserwriter. I assume that I have flow control problems. The present setup is: PC is running the standard DOS 3.1 PRINT program and driver. The cable connection between the PC and the Laserwriter has a null modem box from 3M, with TX1 -> RX2 DTR1 -> DSR2 CTS1 -> RTS1, DCD2 TX2 -> RX1 DTR2 -> DSR1 CTS2 -> RTS2, DCD1 3M calls this a "standard null modem". It seems strange, in that flow control is normally provided via RTS/CTS. Yet the Laserwriter documentation indicates that the Laserwriter tries to do flow control on DSR/DTR, which is nonstandard. The Laserwriter (a IINT) is in DSR/DTR mode, 9600 baud. Postscript files (which are not missing characters) sent to the printer lose 1 to 10 characters on rare occasions, perhaps once every few pages. What are the PC printer conventions on flow control, anyway? Where is this documented? John Nagle