re serial port problem in article qcq ginn q calvin usc edu wls calvin usc edu writes a friend asked me to build a cable to connect an hp fetal heart monitor to a maciontosh se no problem sez i i wanted to demo it on my pb it won t work the pb has been used running zterm and kermit using both internal and external modems so i don t think it s the powerbook per se when i send a to the hp it responds with aa a test of the serial ports it works on the se but not on the pb i thought that the se is connected to earth ground and so is the hp so i connected from the chassis of the hp to the pw audio ground connector still ng any thoughts battery powered devices like the powerbook are sometimes more sensitive to serial port weirdness i had trouble with connecting my mac plus to an hp lx handheld everything else worked okay on that port but not the hp it runs on two penlite batteries it turned out that the plus by accident or by design flaw was putting a volt bias on the serial port that was doing weird things to the hp which has only v dc the hp worked fine when connected to the printer port does your pb screen get dim or anything when connected to the device have you tried using the printer port good luck jamie jamie cox jcox ess harris com phone work harris space systems corp home ms rock barnes blvd the macintosh meeting and drinking society rockledge florida usa speaking only for myself
