frank@dciem.UUCP (Frank Evans) (04/07/86)
Does anyone know what would be the correct pin connection for connecting a Macintosh Plus 8 Pin to a Db25 male connector which would plug the Mac in to an inhouse network as a Vt100? I have been pulling my hair out trying to figure out what the old DB9's connection to a DB25 jack should be. I reluctantly coughed up $40.00 for Apple's 8pin to DB9. Of course the cable only works my HP laserjet printer and nothing else. I again had to hot wire my own modem cable!! I called Apple and they said to follow the pin out instructions in the ImagewriterII's manual but this doesn't seem to work or make sense even when I traced the leads on the new adapter 8Pin to DB9 cable. As I recall in previous times,Apple Canada, misdirected me on my initial wiring up of the DB9's to a DB25.It seems that we are doomed to go thru another trial and error cable period ,with Apple, AGAIN!!. I sometimes think that Apple uses it's customers to figure out what the proper connections actually are!! Regardless, does anyone, out there, know what the wiring would be for connectin of the 8Pin to a DB25 for terminal emulation with the Mac Plus?? Deparate!! and patiently awaiting a reply! After all it has only been 2 months since my Mac has sat staring at the DB25 outlet to its bigger Vax brother!!
borton@sdcc3.UUCP (Chris Borton) (04/15/86)
In article <1830@dciem.UUCP> frank@dciem.UUCP (Frank Evans) writes: >Does anyone know what would be the correct pin connection for connecting a >Macintosh Plus 8 Pin to a Db25 male connector which would plug the Mac in >to an inhouse network as a Vt100? > >I have been pulling my hair out trying to figure out what the old DB9's >connection to a DB25 jack should be. > >I reluctantly coughed up $40.00 for Apple's 8pin to DB9. Of course the >cable only works my HP laserjet printer and nothing else. I again had to hot >wire my own modem cable!! > >I called Apple and they said to follow the pin out instructions in the >Imagewriter II's manual but this doesn't seem to work or make sense even when I >traced the leads on the new adapter 8Pin to DB9 cable. > >Regardless, does anyone, out there, know what the wiring would be for >connectin of the 8Pin to a DB25 for terminal emulation with the Mac Plus?? We've successfully hooked up a Mac+ to our Dataswitch/LAN using Apple's 8-9pin modem adaptor (since it came with the Mac+) and the following scheme for DB-9 to DB-25: (which I'm using right now) DB-9 DB-25 ---- ----- 3----*------------------7 GND 8----| 5--------->-------------2 TXD 9---------<-------------3 RXD 6----------|||||---->---20 DTR 1K Ohm The 1K ohm resistor is for safety only; the +12V could otherwise ground out and possibly blow up either the terminal or the Mac's power supply. This configuration works fine for our standard terminal connectors (previously Dataswitch, now Ungerman/Bass Net/One). -Chris -- ------- Chris Borton, UC San Diego Undergraduate CS; Micro Consultant, UCSD borton@sdcsvax.UCSD.EDU || ...!{ucbvax,decvax,noscvax,ihnp4,bang}!sdcsvax!borton