Path: utzoo!utgpu!water!watmath!clyde!att-cb!att-ih!pacbell!ames!mailrus!tut.cis.ohio-state.edu!bloom-beacon!mit-eddie!uw-beaver!tektronix!reed!omen!caf
From: caf@omen.UUCP (Chuck Forsberg WA7KGX)
Newsgroups: comp.dcom.modems
Subject: Re: Followup on PC mag review of Telebits, etc.
Message-ID: <663@omen.UUCP>
Date: 15 Apr 88 21:34:43 GMT
References: <187@octopus.UUCP>
Reply-To: caf@omen.UUCP (Chuck Forsberg WA7KGX)
Organization: Omen Technology Inc, Portland Oregon
Lines: 25

In article <187@octopus.UUCP> pete@octopus.UUCP (Pete Holzmann) writes:
:	- They never got better than 900 chars/sec out of the Telebit; the
:		same as any of the 9600 baud modems. I wonder if a PC/AT
:		can really handle full 19.2 data rates? On our 68000 box
:		here, we can certainly do better than that! The main
:		limiting factor I've seen is latency due to hard disk
:		accesses.
:
That depends on the software one is using.  The TeleGodzilla bulletin
board runs Professional-YAM on a 4.77 mHz PC with an add-in hard disk
(equivalent to an XT).  It can receive (with ZMODEM protocol) files from
a 386 Xenix system with 1890 cps throughput, and send to Xenix with 1520
cps throughput.  An AT is much faster, but requires 16550A UARTS and
software that knows how to exploit them (DSZ, ZCOMM, Pro-YAM) to avoid
interrupt latency problems at the higher speeds.

TrailBlazer downloads from TeleGodzilla get 600-1400 cps throughput
depending on how many beavers are gnawing on the local loop, etc.
(TeleGodzilla has an old TrailBlazer, not TB Plus.)

Chuck Forsberg WA7KGX          ...!tektronix!reed!omen!caf 
Author of YMODEM, ZMODEM, Professional-YAM, ZCOMM, and DSZ
  Omen Technology Inc    "The High Reliability Software"
17505-V NW Sauvie IS RD   Portland OR 97231   503-621-3406
TeleGodzilla BBS: 621-3746   CIS: 70007,2304    Genie: CAF