wales@valeria.cs.ucla.edu (Rich Wales) (07/26/90)
A few questions about the ZMODEM protocol, including the latest addition
thereto (ZMODEM MobyTurbo):
(1) Since part of my Ph.D. research involves data communication over
serial links, it would be useful for me to find the technical specs
of the ZMODEM protocol. Are these freely available? If so, where?
Can anyone direct me to published technical specs of other protocols
comparable to ZMODEM?
(2) I am using a USRobotics Courier HST modem from school (not a Dual
Standard, and without the recent V.42 upgrade). My serial port has
a NS16550AN UART and is driven at 19.2k bps.
Using straight ZMODEM over an 8-bit data path, I get transfer rates
of about 1050-1080 bytes/second. What kind of transfer rate should
I expect to get with the new "ZMODEM MobyTurbo" option (assuming, of
course, that both sending and receiving sides support MobyTurbo)?
(3) Is the RZSZ material (C source code for RZ and SZ) distributed as
part of the registered DSZ package from Omen Technologies? Or do
you have to pay extra for it, over and above the DSZ registration?
(4) I currently use Telix 3.12, which has ZMODEM builtin. If I decide
to use DSZ instead of the Telix code (something I would presumably
do only if MobyTurbo is fantastically better than straight ZMODEM
=and= if the new MobyTurbo-capable RZSZ source code is cheap), is
there any way to get Telix's "ZMODEM auto-downloads" capability
(option "N" on the "terminal options" setup screen) to fire up the
external program (DSZ) instead of the builtin Telix ZMODEM?
I've got this sick premonition that the answers to my questions will be
something like "proprietary", "a little faster, but not much", "pay lots
more $$$", and "can't be done". But maybe I'll be pleasantly surprised.
--
-- Rich Wales <wales@CS.UCLA.EDU> // UCLA Computer Science Department
3531 Boelter Hall // Los Angeles, CA 90024-1596 // +1 (213) 825-5683
"Indeed! Twenty-four is the gateway to heroic salvation."larry@nstar.uucp (Larry Snyder) (07/27/90)
wales@valeria.cs.ucla.edu (Rich Wales) writes: > Using straight ZMODEM over an 8-bit data path, I get transfer rates > of about 1050-1080 bytes/second. What kind of transfer rate should Assuming you are using the new 14.4 HST, you should be able to get zmodem transfer rates of compressed data of around 1650 cps, and with the older 300 baud back channel modems, rates should run about 1160 cps. >(3) Is the RZSZ material (C source code for RZ and SZ) distributed as > part of the registered DSZ package from Omen Technologies? Or do > you have to pay extra for it, over and above the DSZ registration? Source code is available for free, and is here on nstar in one of the UNIX directories (/usr/public/40 or /usr/public/41). -- Larry Snyder, Northern Star Communications, Notre Dame, IN USA uucp: iuvax!ndmath!nstar!larry -or- larry@nstar Public Access Unix Site (219) 289-0282 (5 lines/PEP/HST/Hayes-V)
timg@smoke.BRL.MIL (Timothy Gion) (07/27/90)
In article <37296@shemp.CS.UCLA.EDU> wales@valeria.cs.ucla.edu (Rich Wales) writes: > >(4) I currently use Telix 3.12, which has ZMODEM builtin. If I decide > " > " > " > there any way to get Telix's "ZMODEM auto-downloads" capability > (option "N" on the "terminal options" setup screen) to fire up the > external program (DSZ) instead of the builtin Telix ZMODEM? Well, I can answer number 4. I have Moby Turbo installed as an external protocol. If I don't turn the Zmodem auto-downloads off, it will start the download using regular Zmodem instead of Moby Turbo. I can only estimate that Moby Turbo is x times faster than regular Zmodem. heh. --Tim