burke@pollux.usc.edu (Sean Burke) (10/14/89)
Well, I finally took the plunge, and shelled out $700 for a Prometheus
Promodem 9600 Plus, which supports v.32 and MNP5. I've got it hooked up
to my Mac at the moment. So far I'm pleased with the modem; I've been
able to connect with USC's Penril Alliances (if memory serves) with no
problems. And let me tell you, it sure is nice to be able to write postings
without line noise trashing my editor buffer at random intervals! I'm not
completely happy however.
Let's talk about modem programs. My modem program is Red Ryder 10.3, and
I'm unhappy with its performance on a number of points.
- RR cannot keep up with the data in terminal mode. The screen doesn't
scroll very much faster than at 2400 baud. If I turn off Xon/Xoff at the
receiving end, much stuff gets lost. By contrast, MacKermit's scrolling
seems to be full speed.
- File transfers are incredibly slow. Xmodem ran at about 140cps,
regardless of whether I use the Xmodem spoofing or not. By contrast,
if I use Freeterm with Xmodem spoofing, I get the highest transfer rate
yet, a screaming 760cps, but spoofing only works when receiveing. Kermit
did better, perhaps because I could set 1K packets. RR and MacKermit both
got into the 250cps range.
- What I would really like to do is to use speed conversion option, with
the serial port set at 19.2kbd, so that I can take advantage of the
compression provided by MNP-5. None of the terminal programs I can
scrape up offer this option, though the modem manual mentions a program
called MAcKNOWLEDGE.
So you say, why not use Freeterm? Well, Freeterm doesn't do v100 emulation.
MacKermit does, and it's starting to look like my terminal program of choice,
if only because the screen will update at full speed.
As long as I'm bitching about RR, I've just got to mention that I _STILL_
haven't been able to turn off that stupid title screen, and I PAID for this
program! And I've never been able to get Xmodem or Kermit to use 1K packets.
So, in summary, V.32 is nice, and you can get it for a reasonable price
these days, but you're going to have to work to take advantage of the new
technology.
Sean Burke
"The nice thing about true hopelessness
is that you don't have to try again" - Jules Shearnews@bbn.COM (News system owner ID) (10/16/89)
(I'm posting a copy of this because it may be of use to other Mac
users out there -- PWP)
burke@pollux.usc.edu (Sean Burke) writes:
< Let's talk about modem programs. My modem program is Red Ryder 10.3, and
< I'm unhappy with its performance on a number of points.
Well, that was your first mistake...
< - RR cannot keep up with the data in terminal mode. The screen doesn't
< scroll very much faster than at 2400 baud. If I turn off Xon/Xoff at the
< receiving end, much stuff gets lost. By contrast, MacKermit's scrolling
< seems to be full speed.
Yup. I suspect that the problem with RR is that it tries to process
each character one at a time. There is a fairly sucessful hack that
Mac Kermit uses to pick up some speed: it buffers normal characters
(when not doing an escape sequence) until it either sees a control
character (that is, non-normal), has to autowrap, or runs out of
chacters to display. Then it writes them all out as a string. This
method works quite well, as long as all the conditions to flush are
right.
< - File transfers are incredibly slow. Xmodem ran at about 140cps,
< regardless of whether I use the Xmodem spoofing or not. By contrast,
< if I use Freeterm with Xmodem spoofing, I get the highest transfer rate
< yet, a screaming 760cps, but spoofing only works when receiveing. Kermit
< did better, perhaps because I could set 1K packets. RR and MacKermit both
< got into the 250cps range.
Try running kermit (protocol) with a large packet size: set the
recieve packet size on both sides to about 950 bytes (1000 works
_slightly_ better, but 950 is a safer guess). This should improve
things somewhat.
The other problem you are probably running into is a delay between
when Kermit is done sending a packet, and when MNP decides to actually
send it across the wire. The best work-around I have to that is to
(gulp) turn off MNP. Obviously there should be a better way -- I
don't know if there is any way to
< - What I would really like to do is to use speed conversion option, with
< the serial port set at 19.2kbd, so that I can take advantage of the
< compression provided by MNP-5. None of the terminal programs I can
< scrape up offer this option, though the modem manual mentions a program
< called MAcKNOWLEDGE.
Mac Kermit 0.98(62) does this. FTP a copy from
watsun.cc.columbia.edu; it's /kermit/test/ckmker.hqx. Don't use
0.97(57) -- it had some font-switching bugs.
< So you say, why not use Freeterm? Well, Freeterm doesn't do v100
< emulation. MacKermit does, and it's starting to look like my
< terminal program of choice, if only because the screen will update
< at full speed.
Retorical question: why use Freeterm? What does it do that Mac Kermit
doesn't (I've never used it)?
< As long as I'm bitching about RR, I've just got to mention that I _STILL_
< haven't been able to turn off that stupid title screen, and I PAID for this
< program! And I've never been able to get Xmodem or Kermit to use 1K packets.
Well, I think this is a reverse version of you get what you pay for.
RR costs and is low quality; Mac Kermit, Freeterm (from what I've
heard), Zterm, and a few others are free and high quality.
< So, in summary, V.32 is nice, and you can get it for a reasonable price
< these days, but you're going to have to work to take advantage of the new
< technology.
I'm glad to hear this. Maybe I'll get a v.32 soon too.... :-)
-- Paul Placeway <PPlaceway@bbn.com>
Mac Kermit coord. (among other things)