UNM406@DBNRHRZ1.BITNET.UUCP (03/27/87)
Date: 25 March 1987, 15:41:20 MEZ
From: Thomas Miller 0228 73 3158 UNM406 at DBNRHRZ1
Math.Inst. Universitaet Bonn
Wegelerstr.10
D - 5300 Bonn 1
(internal use only: Be3,13)
To: LASER-LO at WASHINGT
WE have a HP Laserjet, which is in the moment used simply as a
printer for our IPM PC AT. (via the serial COM1-port). On the way from
the PC to the printer we loose single bytes regularly (but without seeing
a pattern in it).
Has anybody some idea what could happen, or has similar experience?
Thomas Miller
UNM406%DBNRHRZ1.BITNETmetro@asi.UUCP.UUCP (03/28/87)
In article <8703270327.AA28535@ucbvax.Berkeley.EDU>, UNM406@DBNRHRZ1.BITNET writes: > WE have a HP Laserjet, which is in the moment used simply as a > printer for our IPM PC AT. (via the serial COM1-port). On the way from > the PC to the printer we loose single bytes regularly (but without seeing > a pattern in it). > Has anybody some idea what could happen, or has similar experience? > I have seen the same thing with a Diablo 630 printer I was using. The problem turned out to be the following: I was looping the CTS signal from the diablo back to its DTR signal to enable it. However, the printer used the CTS signal as a hardware handshaking line. When the buffer got full it dropped the signal which inturn disabled its receiver -- thus clobbering the character which was currently being transmitted. Only one character was lost, because the transmitting computer respected the handshake, and did not transmit any more characters until the signal came high again. I hope the was you problem also. The resolution was to use a different signal to enable DTR -- preferably one from the transmitting computer. -- Metro T. Sauper, Jr. Assessment Systems, Inc. Director, Remote Systems Development 210 South Fourth Street (215) 592-8900 ..!asi!metro Philadelphia, PA 19106