At 10:40 -0700 4/21/09, jworgan wrote: >before the internet became common place, it was possible to contatct a >friend by dial-up modem > >can that still be done or do all contacts have to be made via internet?
<personal bias on> Sure it's possible. Especially on a low-end Mac. Modern "improvements" to computers can make it difficult though. Modems still need good old RS-232 or, in the Apple world of old, RS-422. Those serial ports have gone missing to be replaced by USB to serial converters that may and may not work with old Hayes-like modems. The RS-232 spec calls for logic one to be a negative voltage between -3 volts and -25 volts. Many new adapters do not produce negative voltages and just assume that nearly 0 volts is good enough. That assumption is OK for new serial devices but can fail for older devices. There is a standard extension called something like "low voltage RS-232" and nobody reads it because it has to be purchased. There are modem cards on modern computers that are set up for FAX. It's likely that one of those would have an AT command set that includes computer to computer connectivity. The chips that do both were designed long ago and who would do the work to make a FAX-only version? You will almost surely NOT get an old fashioned copper connection from the telephone company. The days of relays that connect your phone to another are gone. The audio tones generated by your modem will be immediately digitized on their arrival at the telco office. A computer will connect the digital data to a digital to analog converter that will drive your correspondent's line. Those extra conversions to and from digital will have an effect on performance of older modems that are not expecting it. "Echo cancellation" is a buzzword for searching further. Apple once delivered software modems with its systems. Geoport was a buzzword. That type of modem never worked as well as real ones and would be likely to fail in a digital telco environment. <personal bias off> It's worth a try. Any computer with a real serial port ought to work. zterm should still work and there were lots of UNIX communication options that would likely work even in OS neXt if you can get to a serial port. It's also worth trying to use plain old AT commands on a FAX modem. ATDT to your own number and see if you get a busy signal. Try at a low baud rate - 2400 - to start. -- --> There are 10 kinds of people: those who understand binary, and those who don't <-- --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/vintage-macs?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
