bbloom@brl@sri-unix.UUCP (07/27/83)
From: Bob Bloom (TECOM) <bbloom@brl> OK, I give up; what's modem9xx? that is, vs. mdm7??. And I suppose that there is some confusion on the net of all the various version and flavors of the "christenson protocals". So, does anyone know or have handy what the differences are between xmodem, umodem, modem2??, modem7??, modem9??, tmodem, etc.? For that matter, it probably would be instructive to see a review of all the commo packages, both commercial and public domain, available for cp/m machines; including protocal capabilities, functions supported, hardware supported, etc.; somewhat like the C complier review that went around awhile ago. listening Rich? (Conn that is) -- bob bloom
W8SDZ%mit-mc@sri-unix.UUCP (07/28/83)
From: Keith Petersen <W8SDZ@mit-mc> XMODEM, UMODEM, MODEM2xx, MODEM7xx, MODEM9xx, TMODEM, and MDM7xx ALL use the SAME Christensen protocol. There are no "flavors" except for an OPTION for using a CRC error checking mode instead of the original CHECKSUM error checking mode. This run-time OPTION is available in all of the above-named programs except for UMODEM and TMODEM. MODEM9xx is a generic MODEM7xx program for serial-port modems. It does NOT support the PMMI S-100 modem. MDM711 supports PMMI S-100, D.C. Hayes "Smart Modem", U.S. Robotics intelligent modem, AND serial port modems. Many user overlays are provided for easy customization of the MDM711.COM file, so it is NOT necessary to get the .ASM file to bring up this program. Future support will be provided for the new PMMI MM-212 (1200 baud) S-100 modem. MDM7xx, MODEM7xx and MODEM9xx all provide a "batch transfer" OPTION which allows more than one file to be transferred without operator intervention. Again, this is an OPTION and can be considered an extention of the Christensen protocol rather than a violation of it. It does not have to be used. --Keith