dlb5404@tamuts.tamu.edu (Daryl Biberdorf) (02/19/91)
I was going to hook up the old C.Itoh Prowriter 8510 this weekend
when I noticed that my 3B1 uses a female centronics connector instead
of the more common DB-25 for its parallel port. After calling around,
no local businesses stock the male centronics-male centronics cable I need
and special ordering it looks like it will cost more than I think it should.
:) So I guess I'll make my own.
Anyway, I have the pinouts for the printer (equivalent to the Apple
Imagewriter I and the AT&T 470, I believe), but I don't have them
for the computer. Can anyone help?
In case it matters, here are the pinouts for the Prowriter:
Pin Signal Name
1 DATA STB' (' indicates low true)
2-8 data (2 is LSB, 8 is MSB)
10 ACK'
11 INPUT-BUSY
12 PE
13 SELECT
14 0 V.
15 not connected
16 0 V.
17 CHASSIS GND
18 +5 V. DC
19-30 TWISTED PAIR GND (for pins 1-11 and 31, in order.
What are these for? couldn't tell.)
31 INPUT PRIME'
32 FAULT'
33 0 V.
34 not connected
35 not connected
36 INPUT BUSY
These pin numbers are for the standard 36-pin Centronics-style connector.
Will I need a full 36-conductor cable to accomplish all these connections?
(33 if I ignore the NC pins) If so, how does a clone accomplish
parallel communications with a DB-25 connector and still allow for
communications TO the machine through that connector?
Thanks in advance for any help you can provide.
--Daryl Biberdorf, dlb5404@{rigel,tamuts}.tamu.edu
Texas A&M Universityrhaar@albert.cs.gmr.com (Robert L. Haar CS50) (02/20/91)
In article <12347@helios.TAMU.EDU>, dlb5404@tamuts.tamu.edu (Daryl Biberdorf) writes: |> I was going to hook up the old C.Itoh Prowriter 8510 this weekend |> when I noticed that my 3B1 uses a female centronics connector instead |> of the more common DB-25 for its parallel port. After calling around, |> no local businesses stock the male centronics-male centronics cable I need |> and special ordering it looks like it will cost more than I think it should. |> :) So I guess I'll make my own. |> If your printer uses a standard "Centronics" interface, a straight through cable is all you should need. I have used several printers (Okidata, Epson, and Panasonic) on my UNIXpc using a cable that I made from ribbon cable and the clamp-on connectors. If your local computer stores don't have the male-to-male cables, you can get by with a "printer cable extender" - really a male-to-female centronics cable, and a centronics gender changer. Even Radio shack carries this kind of stuff. Bob Haar InterNet : rhaar@albert.cs.gmr.com Computer Science Dept., G.M. Research Laboratories DISCLAIMER: Unless indicated otherwise, everything in this note is personal opinion, not an official statement of General Motors Corp.
mark@jpl-devvax.JPL.NASA.GOV (7794) (02/20/91)
:: Response to article 395: :: I have been using a C. Itoh 8510 with my PC7300 for over five years. No problems. I use a standard, 36-pin, Amphenol, male-both-ends, Centronics-style, cable :: Vis. "... more common DB-25...": Everyone used 36 Amphenol connectors for parallel, and DB-25's for serial, before IBM, in their infinite wisdom, decided to use DB-25's for both in the their PorkChop (PC) series of machines. How many 5 volt parallel printers have been burned out by the +/- 12V of RS232 since then?
dlb5404@tamuts.tamu.edu (Daryl Biberdorf) (02/20/91)
In article <11489@jpl-devvax.JPL.NASA.GOV> mark@jpl-devvax.JPL.NASA.GOV (Mark R. Rubin 4-7794) writes: > > :: I have been using a C. Itoh 8510 with my PC7300 for over five > years. No problems. I use a standard, 36-pin, Amphenol, > male-both-ends, Centronics-style, cable The problem is that I don't want to buy a ready-made cable. They're kind of pricey around here, and I don't want to have to drive to Houston or Dallas to pick one up at an acceptable price. But before I make my own, I'd like to know exactly how many pins *need* to be hooked up and whether or not they're straight through (pin 1 on computer goes to pin 1 on printer, pin2 to pin 2, etc.). > :: Vis. "... more common DB-25...": Everyone used 36 Amphenol > connectors for parallel, and DB-25's for serial, before IBM, > in their infinite wisdom, decided to use DB-25's for both in > the their PorkChop (PC) series of machines. How many 5 volt > parallel printers have been burned out by the +/- 12V of > RS232 since then? I wasn't attempting to make a judgment about the merits of using DB-25 for a parallel connector. However, the PC "standard" is now 10 years old and has an installed base of somewhere around 80 million. Fat chance you're gonna stop that juggernaut on the basis of whether or not it adheres to the norm 10 years ago. As for burning out printers, probably not many in recent years, anyway. If I remember correctly, IBM boxes (actually made by IBM) use different genders for the serial and parallel ports. I usually try not to just jab a connector into a socket without looking at its label, anyway. Those who do are asking for disaster. Anyway, this is in no way intended to be a flame. I'll still appreciate any help anyone can give as far as whether or not I can wire a cable straight through and exactly which connections need to be made (fewer conductors means less cost for my cable). --Daryl Biberdorf, dlb5404@{rigel,tamuts}.tamu.edu Texas A&M University
ward@tsnews.Convergent.COM (Ward Griffiths) (02/20/91)
dlb5404@tamuts.tamu.edu (Daryl Biberdorf) writes: >I was going to hook up the old C.Itoh Prowriter 8510 this weekend >when I noticed that my 3B1 uses a female centronics connector instead >of the more common DB-25 for its parallel port. After calling around, >no local businesses stock the male centronics-male centronics cable I need >and special ordering it looks like it will cost more than I think it should. >:) So I guess I'll make my own. You can get the clamp-on Centronics connectors and the ribbon cable at any Radio Shack, and I believe that the Radio Shack Computer Centers stock an assembled "printer extension cable" that has the two correct connectors as well. Remember, the "more common" DB-25 connector was not used for parallel ports untill the IBM PC came out, with a male instead of female serial connector (female makes a lot more sense to me -- if a pin breaks it's easier and cheaper to replace a cable than to repair the CPU) and a parallel connector that looked like everybody else's serial connectors. In the early days, I saw several examples of hardware fried by folks thinking that it was a serial port. Of course, nothing like the time someone plugged a Tandy Daisy Wheel Printer II (a machine I had thought impossible to break) into the female DB-25 connector that serves signal AND power to AT&T monitors in the back of an AT&T 6300. Smoke city for CPU and printer. >Anyway, I have the pinouts for the printer (equivalent to the Apple >Imagewriter I and the AT&T 470, I believe), but I don't have them >for the computer. Can anyone help? Pin one to pin one, pin 36 to pin 36, and everything in between follow suit. >These pin numbers are for the standard 36-pin Centronics-style connector. >Will I need a full 36-conductor cable to accomplish all these connections? >(33 if I ignore the NC pins) If so, how does a clone accomplish >parallel communications with a DB-25 connector and still allow for >communications TO the machine through that connector? IBM did away with a number of redundant ground lines that were in the 36-pin connectors. -- Ward Griffiths, Unisys NCG aka Convergent Technologies The people that make Unisys' official opinions get paid more. A LOT more. =========================================================================== To Hell with "Only One Earth"! Try "At Least One Solar System"! If I say love, I'll sound sentimental, and if I say sex, I'll sound cynical. I'll call it pair bonding and sound scientific. The Golden Apple
dnichols@ceilidh.beartrack.com (DoN Nichols) (02/21/91)
In article <1086@tsnews.Convergent.COM> ward@tsnews.Convergent.COM (Ward Griffiths) writes: [ ... part of original question deleted ... ] >that has the two correct connectors as well. Remember, the >"more common" DB-25 connector was not used for parallel ports >untill the IBM PC came out, with a male instead of female >serial connector (female makes a lot more sense to me -- if a >pin breaks it's easier and cheaper to replace a cable than to >repair the CPU) and a parallel connector that looked like >everybody else's serial connectors. In the early days, I saw In spite of the horror stories that followed in the previous article, (now deleted) this is one thing that IBM did RIGHT. (Well, the serial connector at least -- I still shudder at the use of the DB25 for the parallel, but that was forced on them by the size of the brackets, and considerations of board spacing. (Why didn't they just put cutouts for the 36-pin blue ribbon in the back panel above the keyboard connector.? ) About the only other ones that did it right are DEC (vt100) and Televideo (970). (There may be others, and if so, I'm sure I'll hear about them :-) The REASON that this is right, is that it distinguishes between DTE (the terminal/computer) and DCE (the modem). If you can look at a device and determine that it is DTE or DCE by the gender of the connector, it saves a lot of interface problems that need not exist. If all cables with a different gender on each end were wired straight through, and all with the same gender on each end were KNOWN to be a fairly generic null modem connection, interfacing would be less of an art, and more the simple thing that it should be. (Leaving just baud rate, parity, stop bits, 7/8 data bits, ASCII/EBCIDIC/UNAMEIT to deal with :-) IEEE-488 has the right idea. [ ... lots more deleted - almost as much as I typed :-) ... ] -- Donald Nichols (DoN.) | Voice (Days): (703) 664-1585 D&D Data | Voice (Eves): (703) 938-4564 Disclaimer: from here - None | Email: <dnichols@ceilidh.beartrack.com> --- Black Holes are where God is dividing by zero ---
jon@jonlab.UUCP (Jon H. LaBadie) (02/23/91)
Sorry Daryl, nothing against you, your posting just struck a sensitive cord: In article <12347@helios.TAMU.EDU>, dlb5404@tamuts.tamu.edu (Daryl Biberdorf) writes: > I was going to hook up the old C.Itoh Prowriter 8510 this weekend > when I noticed that my 3B1 uses a female centronics connector instead > of the more common DB-25 for its parallel port. After calling around, > no local businesses stock the male centronics-male centronics cable ARGGGGGGGGGGGH! More PC-centric hogwash! Prior to the IBM-PC, the primary parallel interface used the 36 pin "Centronics" connector. None, to my know- ledge, used a DB-25. Then big blue decided to make its serial port use the DB-9 and the parallel port use the DB-25 connector. Both against "industry" standards. I can still remember nievely connecting a modem to the DB-25 "serial" port on an IBM-PC and blowing 6 chips on the modem because of the higher voltages on the parallel port than the serial modem was designed for. Please, Convergent/AT&T got it right on the UNIX-PC. The parallel port is a 36 pin Centronics type connector. A male-male centronics cable can be obtained from any non-PC-CENTRIC supply house. I can remember a shouting match between me an a Rat Shack sales person over the phone who claimed there was no computer in the WORLD that had a 36 pin connector. I said I was looking at a UNIX-PC and it had one. He said he had a UNIX-PC at home just like the one for sale in the store and it did not have a 36 pin connector! ARRRRRRGH. Sorry for the Band Width, I'm not enamored with PC"s. ;-) Jon -- Jon LaBadie {att, princeton, bcr, attmail!auxnj}!jonlab!jon
dave@dms3b1.uucp (Dave Hanna) (02/27/91)
In article <12356@helios.TAMU.EDU> dlb5404@tamuts.tamu.edu (Daryl Biberdorf) writes: >In article <11489@jpl-devvax.JPL.NASA.GOV> mark@jpl-devvax.JPL.NASA.GOV (Mark R. Rubin 4-7794) writes: >> >> :: I have been using a C. Itoh 8510 with my PC7300 for over five >> years. No problems. I use a standard, 36-pin, Amphenol, >> male-both-ends, Centronics-style, cable > >The problem is that I don't want to buy a ready-made cable. They're kind >of pricey around here, and I don't want to have to drive to Houston >or Dallas to pick one up at an acceptable price. But before I make >my own, I'd like to know exactly how many pins *need* to be hooked up >and whether or not they're straight through (pin 1 on computer goes to >pin 1 on printer, pin2 to pin 2, etc.). If you're not _real_ concerned about RFI, (i.e., you don't live in an apartment complex with 3 different neighbors TV sets within a 30 foot radius :^), you ought to be able to get a pair of ribbon cable type connectors and a length of 36 conductor cable from someplace like Radio Shack and make your own pretty easily. The connectors will probably set you back about $5 apiece, and maybe .50 a foot for the cable. If you have a vice to squeeze the connectors in, it shouldn't take more than 10 minutes or so to make up the cable. If your Radio Shack doesn't have the necessary parts, we have a place up here in Dallas called Off the Shelf Components that stocks all sorts of stuff. I'm pretty sure they will do phone/mail order, and I don't think they have a minimum. I've dealt with them before, though on a walk-in basis. Phone number is (214) 247-0052. >Anyway, this is in no way intended to be a flame. I'll still appreciate >any help anyone can give as far as whether or not I can wire a cable >straight through and exactly which connections need to be made (fewer >conductors means less cost for my cable). The actual wires are a small part of the cost - most of it is the connectors. If you use ribbon cable as I suggested, the difference between, say 10 feet of 36 conductor and 10 feet of 25 conductor isn't going to be that much. I'm usually much more concerned with being able to get it done easily and quickly than with saving a dollar or two. Anyway, if you really insist, I think you'll find that the DB-25 solutions drop some of the extra ground wires. The standard pinout, when run through a ribbon cable, gives you a ground wire between each data wire, which provides both noise suppression and cross-talk immunity. But data going to a printer is not that fast that noise needs to be too much of a concern. If you wanted to connect those ground pins together at the connectors and just run 1 or 2 ground lines through the cable, you probably wouldn't get in any trouble. > >--Daryl Biberdorf, dlb5404@{rigel,tamuts}.tamu.edu > Texas A&M University -- Dave Hanna, Infotouch Systems, Inc. | "Do or do not -- There is no try" P.O. Box 584, Bedford, TX 76095 | - Yoda (214) 358-4534 (817) 540-1524 | UUCP: ...!letni!dms3b1!dave |