fdm@WLV.IMSD.CONTEL.COM (Frank D. Malczewski) (09/01/90)
Given that the local dealer I finally got my NT from recommended this solution,
but given that the other two dealers I talked to came up with two different
solutions, I pose the following two questions:
1. Why does Apple recommend in the manual the use of "LocalTalk Locking
Connector Kits" (2) plus a DIN-8 2-meter cable for connecting the NT
to the Mac, when just a single DIN-8 cable does just fine (obviously
in a single-Mac configuration)?
2. At what speed is the connection between the Mac and the NT supposed to
run (I do not recall ever having seen such information). I sent a
postscript program of some sort to the NT and it indicates that the
line is running at 9600 baud. Is this the correct value? [This seems
somewhat slow to me, but given that other software may be running
while the NT is receiving data I suppose this is a reasonable compromise.]
Any ideas?
--Frank Malczewski (fdm@wlv.imsd.contel.com)
(malczews@nunki.usc.edu)boomer@eleazar.dartmouth.edu (Rich Akerboom) (09/01/90)
In <57584@wlbr.IMSD.CONTEL.COM> fdm@WLV.IMSD.CONTEL.COM (Frank D. Malczewski) writes: >Given that the local dealer I finally got my NT from recommended this solution, >but given that the other two dealers I talked to came up with two different >solutions, I pose the following two questions: >1. Why does Apple recommend in the manual the use of "LocalTalk Locking > Connector Kits" (2) plus a DIN-8 2-meter cable for connecting the NT > to the Mac, when just a single DIN-8 cable does just fine (obviously > in a single-Mac configuration)? I think that you misunderstand what is going on here. The normal mac to lw connection is via a Localtalk NETWORK, not a serial cable. Not sure if just using the single DIN-8 cable will work, since I don't know if pins 2&3 need to be reversed (one man's send is another's receive). But you can get much greater speeds with Localtalk (230.4 Kb/s if i remember correctly) than with a serial connection (is 19.2 Kb/s max?). To make the network, you need the 2 boxes and the connector cable, though I'm not sure why it needs to be 2 meters long. >2. At what speed is the connection between the Mac and the NT supposed to > run (I do not recall ever having seen such information). I sent a > postscript program of some sort to the NT and it indicates that the > line is running at 9600 baud. Is this the correct value? [This seems > somewhat slow to me, but given that other software may be running > while the NT is receiving data I suppose this is a reasonable compromise.] see above >Any ideas? >--Frank Malczewski (fdm@wlv.imsd.contel.com) > (malczews@nunki.usc.edu) rich -- Rich Akerboom Internet, etc.: boomer@eleazar.dartmouth.edu Sylvan Software UUCP: decvax!dartvax!eleazar!boomer P. O. Box 566 Telephone: (802) 649-2238 Norwich, VT 05055 USA
malczews@aludra.usc.edu (Frank Malczewski) (09/02/90)
In article <24032@dartvax.Dartmouth.EDU> boomer@eleazar.dartmouth.edu (Rich Akerboom) writes: > >I think that you misunderstand what is going on here. The normal mac to lw >connection is via a Localtalk NETWORK, not a serial cable. Not sure if just >using the single DIN-8 cable will work, since I don't know if pins 2&3 need >to be reversed (one man's send is another's receive). But you can get much >greater speeds with Localtalk (230.4 Kb/s if i remember correctly) than with >a serial connection (is 19.2 Kb/s max?). To make the network, you need the 2 >boxes and the connector cable, though I'm not sure why it needs to be 2 meters >long. What is it exactly that these connectors do? Apparently they are more than just passive devices, somehow indicating that a network is in progress, so go ahead and crank out 230.4 Kbps? The serial connection that I have set up is from the Mac's printer port to the NT's port. It works; I was just wondering whether it could be working better... Any pointers to Apple documents that might provide specifics on these connectors and/or this type of setup? -- -- Frank Malczewski (malczews@nunki.usc.edu)
fswrr@acad3.fai.alaska.edu (rector walter r) (09/02/90)
In article <11789@chaph.usc.edu>, malczews@aludra.usc.edu (Frank Malczewski) writes... >In article <24032@dartvax.Dartmouth.EDU> boomer@eleazar.dartmouth.edu (Rich Akerboom) writes: >> >>I think that you misunderstand what is going on here. The normal mac to lw >>connection is via a Localtalk NETWORK, not a serial cable. Not sure if just >>using the single DIN-8 cable will work, since I don't know if pins 2&3 need >>to be reversed (one man's send is another's receive). But you can get much >>greater speeds with Localtalk (230.4 Kb/s if i remember correctly) than with >>a serial connection (is 19.2 Kb/s max?). To make the network, you need the 2 >>boxes and the connector cable, though I'm not sure why it needs to be 2 meters >>long. > >What is it exactly that these connectors do? Apparently they are more than >just passive devices, somehow indicating that a network is in progress, so >go ahead and crank out 230.4 Kbps? > >The serial connection that I have set up is from the Mac's printer port to >the NT's port. It works; I was just wondering whether it could be working >better... > >Any pointers to Apple documents that might provide specifics on these >connectors and/or this type of setup? > > >-- > >-- Frank Malczewski (malczews@nunki.usc.edu) If you only want to have your laserwriter hooked up to one Mac, then all you need is a null modem cable (I think that the cable that is used to connect the Mac to an Imagewriter is such a cable). Even though this cable is often called a serial cable, it doesn't mean that you have a standard async serial connection to your Laserwriter if you are using it. Assuming that the connectors on the personal NT are the same as those on the II NT, there should be three places that you could plug in to. One is an ADB (i.e. keyboard and mouse type) connector, that is used with some extended sheet feeders. Another is a 25 pin connector that supports a standard RS-232 async serial connection, and the third is a 9 pin mini-din that supports a LocalTalk network connection. If you are plugged into the DB-9 (9 pin) connector, then you are using LocalTalk and it doesn't matter if you are using a single cable or the boxes (Apple's, PhoneNet, etc). You can verify this by checking the chooser; if appletalk is active, and the printer is plugged into the printer port, then you are "networked", and getting the benifits of 230.4 Kbps transfer rates. The 9600 baud value that you saw on the test page relates to the speed you would use if you connected up to the RS-232 port. >What is it exactly that these connectors do? The boxlike connectors provide 3 main functions. 1) They provide a "T" connection, so that you can have a network with more than 2 devices (generally considered desirable). 2) They provide electrostatic sheilding, so that (hopefully) if an errant voltage spike enters your network cableing, your Mac's are protected. 3) They provide a terminating resister to the "end" of your network. (Some, such as Apple's, do this automatically, while others, such as PhoneNet, require you to put in a plug for unused connectors. Most of this information cane from appendix A of Inside Appletalk from Addison-Wesley, ISBN 0-201-19257-8. Kindof a long-winded post to just say "your serial cable works great", but hopefully the added info will make it clearer. -Reed FSWRR@acad3.fai.alaska.edu (internet) FSWRR@ALASKA (bitnet)
whit@milton.u.washington.edu (John Whitmore) (09/28/90)
In article <24032@dartvax.Dartmouth.EDU> boomer@eleazar.dartmouth.edu (Rich Akerboom) writes: > > ... The normal mac to lw >connection is via a Localtalk NETWORK, not a serial cable. Not sure if just >using the single DIN-8 cable will work, since I don't know if pins 2&3 need >to be reversed (one man's send is another's receive). But you can get much >greater speeds with Localtalk (230.4 Kb/s if i remember correctly) than with >a serial connection (is 19.2 Kb/s max?). To make the network, you need the 2 >boxes and the connector cable, though I'm not sure why it needs to be 2 meters >long. In fact, the network software works fine with a simple null modem style cable. It runs at full speed, claims (in the CHOOSER menu) to be a connected AppleTalk network, and everything. The boxes are really only isolation transformers with a couple of resistors to limit bus loading when a connected Mac is turned off. Lots of small systems are connected with null-modem style wiring. It works. John Whitmore