rlcarr@athena.mit.edu (Richard L. Carreiro) (10/22/90)
I'm thisclose to getting a USR Dual Standard (for $879 - is that a decent price?). Some questions first, though: 1) does it have a standard modular phone jack on it, or do I have to rig something up? 2) At what baud rate do I set my terminal program? Can the terminal program be left at the same baud rate all the time, and the modem will simply buffer up stuff (if it's connected at a slower rate) and then send high-speed batches to my terminal? (Or is this all explained in the modem docs?) 3) If I am connected to another USR, and I want to do a file transfer, do I have to use a protocol (like ZMODEM or something), or can I just do a raw transfer and the modems' built-in error checking will guarantee no errors? 4) Will the USR connect to boring old things like Hayes-compatible 2400 baud modems and stuff like that? 5) Assuming I've connected to another MNP 5 modem (of whatever baud rate), should I turn off modem compression when I am transferring a compressed file? Any other things you think I should know, feel free to send them along as well. Thanks in advance for your help! -- Rich Carreiro The "War on Drugs" ARPA: rlcarr@athena.mit.edu is merely a smokescreen for UUCP: ...!mit-eddie!mit-athena!rlcarr The War on the Constitution BITNET: rlcarr@athena.mit.edu JITTLOV FOREVER!
mjs@cbnews.att.com (martin.j.shannon) (10/23/90)
In article <1990Oct22.163151.16067@athena.mit.edu>, rlcarr@athena.mit.edu (Richard L. Carreiro) writes: > I'm thisclose to getting a USR Dual Standard (for $879 - is that > a decent price?). Some questions first, though: Yes, that's a decent price. I paid a hair under "list" for mine (long story...). > 1) does it have a standard modular phone jack on it, or do I have to > rig something up? It has 2 modular jacks on it: one goes to the telephone line, and the other is used if you also want a telephone on that line. > 2) At what baud rate do I set my terminal program? Any baud rate you like. As with most modems that recognize the "AT" command set, it does autobauding from the "AT" characters. > Can the terminal > program be left at the same baud rate all the time, and the modem will > simply buffer up stuff (if it's connected at a slower rate) and then > send high-speed batches to my terminal? Mostly, but I don't recommend that mode of operation (for various reasons). > (Or is this all explained in the > modem docs?) Yes, it is explained in the manual. > 3) If I am connected to another USR, and I want to do a file transfer, do > I have to use a protocol (like ZMODEM or something), or can I just do > a raw transfer and the modems' built-in error checking will guarantee > no errors? As with all modems, you want a path from disk to disk that is error free. The modems will only provide error free paths from serial port to serial port. If your serial port can't keep up with the bandwidth, and drops characters, for instance, all the error checking in the world (done by the modems) won't detect or correct that problem. Use a protocol (some are much better than others; ZMODEM was designed to be better than most...). > 4) Will the USR connect to boring old things like Hayes-compatible 2400 > baud modems and stuff like that? Yes, it connects to any modem correctly implementing any of the protocols that the DS supports. Off the top of my head, that includes: V.21, V.22bis, V.32, HST14400, Bell103, Bell212A. Probably 1 or 2 more, as well. > 5) Assuming I've connected to another MNP 5 modem (of whatever baud > rate), should I turn off modem compression when I am transferring > a compressed file? In general, you should. What will happen if you don't is that the modems will attempt to compress the already compressed file, resulting in a negative compression rate for the modem compression -- i.e., the modems will transfer *more* characters than there are in the file. > Any other things you think I should know, feel free to send them along as > well. Thanks in advance for your help! See my recent myriad of posts on 'e' protocol of uucp if you're going to be using this modem with a UNIX* system. * - UNIX is a registered trademark of AT&T. -- Marty Shannon; AT&T Bell Labs; Liberty Corner, NJ, USA (Affiliation is given for identification only: I don't speak for them; they don't speak for me.)