 path edu!rochest!udel!bogu sura net!new-feed-1 peachnet edu!emori!wupost!howland reston an net!zaphod mp ohio-state edu!sdd hp com!nigel msen com!math fu-berlin de!easix!jester!michael from michael jester gun michael gerhard newsgroup comp sy ibm pc hardwar distribut subject re how null modem cabl? x-newsread tin version 1 1 pl8 refer 1993apr20 174525 5046 vax cn muskingum messag-id 93042275 jester gun organ privat coher system date thu 22 apr 93 17 28 35 gmt line 76 kevin kimmel - comput scienc german undergrad ke kimmel vax cn muskingum wrote interrest extrodinarili simpl concept null modem cabl actual no idea count statement what i'm pin specif? solder bui port db-25 db-9 pin pin name eia ccitt dte-dce descript ------------------------------------------------------------------------------ 1 fg aa 101 ---- frame ground 2 3 td ba 103 --- transmit data 3 2 rd bb 104 --- receiv data 4 7 rt ca 105 --- request send 5 8 ct cb 106 --- clear send 6 6 dsr cc 107 --- data set readi 7 5 sg ab 102 ---- signal ground 8 1 dcd cf 109 --- data carrier detect 9 -- -- - - posit dc test voltag 10 -- -- - - neg dc test voltag 11 qm -- - --- equal mode 12 sdcd scf 122 --- secondari data carrier detect 13 sct scb 121 --- secondari clear send 14 std sba 118 --- secondari transmit data 15 tc db 114 --- transmitt clock 16 srd sbb 119 --- secondari receiv clock 17 rc dd 115 --- receiv clock 18 dcr -- - --- divid clock receiv 19 srt sca 120 --- secondari request send 20 4 dtr cd 108 2 --- data termin readi 21 sq cg 110 --- signal qualiti 22 9 ri ce 125 --- ring indic 23 -- ch 111 --- data rate selector 24 -- ci 112 --- data rate selector 25 tc da 113 --- transmit clock - - - post - - - - - - author - - - - - connect devic ------------------ normal 7 wire connect connect gnd1 gnd2 rxd1 txd2 txd1 rxd2 dtr1 dsr2 dsr1 dtr2 rt1 ct2 ct1 rt2 if modem connect add line ri dcd if softwar connect dcd1 ct1 dcd2 ct2 bewar! while pc pin 2 rxd pin 3 txd modem pin revers! thi allow easili connect pin1 pin1 pin2 pin 2 if connect pc cross rxd txd if hardwar handshak need so-call null-modem connect connect gnd1 gnd2 rxd1 txd2 txd1 rxd2 addition connect softwar rt1 ct1 dcd1 rt2 ct2 dcd2 dtr1 dsr1 dtr2 dsr2 you long wire these! the null-modem connect establish xon xoff-transmiss pc softwar detail rememb name dtr dsr ct rt refer line pc thi data set dtr rt incom signal dsr ct output! - - - - - - - michael -- michael jester gun michael gerhard preussenstrass 59 germani 4040 neuss voic 49 2131 82238 