tarkkonen@cc.helsinki.fi (01/13/90)
1200 BAUD A BOTLENECK IN LASERWRITER NTII The department has one Apple LaserWriter NTII connected to a Unisys PW300 through the serial interface. The transfer of the data is quite unreliable, and using the speed 9600 baud will cause io errors about every second page. If the speed is redused to 1200 bauds the operation is faultless. The programs we use write to the LPT1 port and it is redirected the normal way using: MODE LPT1:=COM2:. The LaserWriter NTII owners manual says the serial port should be configured: MODE COM2:9600,N,7,1,P but it does not work, it must be configured: MODE COM2:9600,N,8,1,P to work at all. This is the way my AST TurboLaser/PS manual tells me to configure the port. The same programs write perfectly with both serial and parallel ports with my AST TurboLaser/PS, here I use mostly the parallel interface, but I have tested the programs and procedures I have tried on the LaserWriter NTII with the serial interface and they work ok. Has anybody some knowledge or experience with this Apple printer. I have tested several computer with the printer, so I do not believe there is anything wrong with the serial port ow the computer. Is this a bug in the computer of the department or is it a feature of the Apple LaserWriter NTII? Lauri Tarkkonen Univeristy of Helsinki Finland
izumi@violet.berkeley.edu (Izumi Ohzawa) (01/14/90)
In article <1731.25ae524c@cc.helsinki.fi> tarkkonen@cc.helsinki.fi writes: >1200 BAUD A BOTLENECK IN LASERWRITER NTII > >The department has one Apple LaserWriter NTII connected to a Unisys PW300 >through the serial interface. The transfer of the data is quite unreliable, >and using the speed 9600 baud will cause io errors about every second page. >If the speed is redused to 1200 bauds the operation is faultless. > >The programs we use write to the LPT1 port and it is redirected the normal >way using: MODE LPT1:=COM2:. > Looks like a problem with improper handshake. Out of the box, PC (clones) and MSDOS cannot handle software handshake (XON/XOFF or Control-S/Control-Q) to throttle transimission to the serial device. On the other hand, out of the box, LaserWriters are configured to do this software handshake. Solution: Look in the LaserWriter (NTII) manual for the section describing serial port handshake. There should be a short command sequence for changing the default software handshake to hardware handshake. Choose the command to set it to DTR/... handshake. Since this command sequence is so short, you should be able to send this sequence by doing a simple copy: copy commandfilename LPT1 or copy commandfilename COM2 (if not redirected). Make sure also that the cable has a wire going from Pin-20 (?) on the LaserWriter side (DTR wire). Izumi Ohzawa izumi@violet.berkeley.edu
woody@rpp386.cactus.org (Woodrow Baker) (01/14/90)
In article <1731.25ae524c@cc.helsinki.fi>, tarkkonen@cc.helsinki.fi writes: > > The programs we use write to the LPT1 port and it is redirected the normal > way using: MODE LPT1:=COM2:. > > The LaserWriter NTII owners manual says the serial port should be > configured: MODE COM2:9600,N,8,1,P to work at all. This is the way > my AST TurboLaser/PS manual tells me to configure the port. > > The same programs write perfectly with both serial and parallel ports > with my AST TurboLaser/PS, here I use mostly the parallel interface, > but I have tested the programs and procedures I have tried on the > LaserWriter NTII with the serial interface and they work ok. I'd be willing to bet that the following is the problem: MS-DOS machines don't work with XON/XOFF protocol using normal dos redirections. The problem is that Microsoft DOS, doesn't have the intellegence to know what it is doing. It can't input from a paralell port. There are 2 solutions. the first one is install AST superspool and let it handle the redirection. This program is a spooler that can be told about XON/XOFF. The second thing is to makesure that your computer printer cable is wired for DTR/DSR. The cable that I use and appears to work for a QMS-ps810 is symetrical. What you do to one end, you do to another 2-\__________________/-3 3/-------------------\2 (cross these for XT) 5\----------------------\4 4/-----------------------/5 cross these 6--| | 8-----------------------20 Do the same thing on the other end. You also need to makesure that the laser is set to either xon/xoff or if you are using superspool, although superspool can handle DTR/DSR as well. If you don't want to use superspool, then make sure it is DTR/DSR and try the above cable. You'd probably better off to use paralell if you have it. Cheers Woody p > Has anybody some knowledge or experience with this Apple printer. > I have tested several computer with the printer, so I do not believe > there is anything wrong with the serial port ow the computer. > Is this a bug in the computer of the department or is it a feature > of the Apple LaserWriter NTII? > > Lauri Tarkkonen > Univeristy of Helsinki > Finland
vgopal@cbnewsc.ATT.COM (venu.p.gopal) (01/18/90)
!> The programs we use write to the LPT1 port and it is redirected the normal !> way using: MODE LPT1:=COM2:. !> !> The LaserWriter NTII owners manual says the serial port should be !> configured: MODE COM2:9600,N,8,1,P to work at all. This is the way !> my AST TurboLaser/PS manual tells me to configure the port. !> !> The same programs write perfectly with both serial and parallel ports !> with my AST TurboLaser/PS, here I use mostly the parallel interface, !> but I have tested the programs and procedures I have tried on the !> LaserWriter NTII with the serial interface and they work ok. ! !I'd be willing to bet that the following is the problem: !MS-DOS machines don't work with XON/XOFF protocol using normal dos redirections. !The problem is that Microsoft DOS, doesn't have the intellegence to know what !it is doing. It can't input from a paralell port. There are 2 solutions. !the first one is install AST superspool and let it handle the redirection. !This program is a spooler that can be told about XON/XOFF. The second !thing is to makesure that your computer printer cable is wired for DTR/DSR. !The cable that I use and appears to work for a QMS-ps810 is symetrical. !What you do to one end, you do to another If you can save the postscript output from your program into a file, you can use a utility I wrote called COMSEND to send it to the printer using XON/XOFF protocol. If there is sufficient interest, I'll post it to comp.lang.postscript. Venu P. Gopal UUCP: ..!att!ihuxy!vgopal Internet: vgopal@ihuxy.att.com