sutter@skat.usc.edu (Carl Sutter) (08/19/89)
For the sake of the archives, and news readers (like me) out there... The original question was how to get an Apple Laserwriter Plus to work reliably as a serial port connected printer to the cube. The solution was to scrap and re-load the network configuration, and since that is taken care of by systems people here, I unfortunately can't explain why it worked. Maybe noone can :-) Some of the images in the docs are in an Encapsulated PostScript format that the printer will not handle. (ex. Ch. 3, p. 19 in the 0.9 system) The interesting thing is that the cabling can be connected to either the DB25 or the DB9 connectors on the LaserWriter. When the switch is set to 9600 baud, the DB25 is RS-232, and the DB9 is RS-422 (like the NeXT!). The wiring is actually NOT a null-modem, and a possible confusing point is to put two null-modems in line, since an off the shelf Mac-Modem cable is a null-modem. The important wires to connect for RS-232 are: NeXT DIN 8 LaserWriter Plus DB25 3 TxD- ------------- TD 2 4 GND ------------- CGND 7 5 RxD- ------------- RD 3 An RS-422 is just a straight through connector: (The LaserWriter Plus doesn't use hardware handshaking) NeXT DIN 8 LaserWriter Plus DB9 3 TxD- ------------- TxD- 5 4 GND ------------- GND 3 5 RxD- ------------- RxD- 9 6 TxD+ ------------- TxD+ 4 8 RxD+ ------------- RxD+ 8 I know this is a little esoteric, since most laser printers are networked, but it takes awhile to combine all the bits and pieces of information that people have into a coherent picture. I'm happy to answer questions about the cabling. Carl F. Sutter sutter@skat.usc.edu
greid@adobe.com (Glenn Reid) (08/22/89)
In article <19278@usc.edu> sutter@skat.usc.edu (Carl F. Sutter) writes: >The original question was how to get an Apple Laserwriter Plus to work >reliably as a serial port connected printer to the cube. > ... >The wiring is actually NOT a null-modem, and a possible confusing point is to >put two null-modems in line, since an off the shelf Mac-Modem cable is a >null-modem. I bought an off-the-shelf cable for connecting a Macintosh to an ImageWriter. It works perfectly with my LaserWriter II NTX and I imagine it would also work fine with a LaserWriter Plus, since they are equivalent at the serial communications level. I started out asking the people at the store if they had a cable for connecting a LaserWriter to a Mac through the serial port. They had no idea that it was even possible (it isn't very well supported, if at all, on the host end). The word "ImageWriter" brought a knowing sales smile to his face, though. And since the ImageWriter is somewhat out of fashion I only paid about $10 for the cable.... Glenn Reid Adobe Systems
dz@kiwi.ucsb.edu (Daniel James Zerkle) (08/23/89)
In article <1096@adobe.UUCP> greid@adobe.COM (Glenn Reid) writes: >In article <19278@usc.edu> sutter@skat.usc.edu (Carl F. Sutter) writes: >>The original question was how to get an Apple Laserwriter Plus to work >>reliably as a serial port connected printer to the cube. >> ... >>The wiring is actually NOT a null-modem, and a possible confusing point is to >>put two null-modems in line, since an off the shelf Mac-Modem cable is a >>null-modem. > >I bought an off-the-shelf cable for connecting a Macintosh to an >ImageWriter. It works perfectly with my LaserWriter II NTX and I >imagine it would also work fine with a LaserWriter Plus, since they >are equivalent at the serial communications level. The null modeming business is confusing. We have port A on a Mac modem cable running out to the rest of the world through an RJ11 (phone cord) adapter. We have port B connected to a Mac *printer* cable which runs to a vt-100 (genuine DEC). These cables actually look identical, but they are not. I assume one of them is in fact a null modem, (probably the printer cable) and the other is not. On the other hand, they both work, so there's no point in complaining. >I started out asking the people at the store if they had a cable for >connecting a LaserWriter to a Mac through the serial port. They had >no idea that it was even possible. My salesperson was even more confused. I showed him the wiring diagram for the cable to connect to the terminal, and he said "we don't have that". I looked at the rack, decided that the printer cable was as good a gamble as any, and got lucky. >The word "ImageWriter" brought a knowing >sales smile to his face, though. No surprise. All salespeople understand money. | Dan Zerkle home:(805) 968-4683 morning:961-2434 afternoon:687-0110 | | dz@cornu.ucsb.edu dz%cornu@ucsbuxa.bitnet ...ucbvax!hub!cornu!dz | | Snailmail: 6681 Berkshire Terrace #5, Isla Vista, CA 93117 | | Disclaimer: If it's wrong or stupid, pretend I didn't do it. |