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Transcript on a seminar about Telepathy
The Gateway TelePath Fax/Modem:
"Which Rumors are True and Why Most are Not"
Tim Gilbert, Gateway 2000 Product Development
The Gateway "TelePath" modem has raised a lot of questions lately. I
don't have time or space to get into the eye patterns, trellis coding
and everything else, but this memo should put most of the rumors to
rest.
Overview: The TelePath is a 14,400 bps fax/modem designed by Gateway
using the latest Rockwell chip set. The actual boards are assembled
in Rapid City, SD. by a major board house under contract to Gateway.
The design uses a C19 Rockwell controller, RC144 Digital Signal
Processor, two PROMs and miscellaneous support chips. The maximum
data transfer between the modem and the host computer is actually
115.2 kbps, but this is beyond what the data compression routine can
utilize; therefore, there is no reason to set the DTE speed higher
than 57,600.
Bad Chips: Rumor has it that Rockwell shipped defective silicon.
This is completely false! However, there was a bug in the original
firmware that affected the fax handshaking. (firmware: software
contained in PROMs. It is used by the on-board processor; similar
function as the BIOS on your mother board.) Unfortunately, it caused
problems with a small number of fax machines. I say "unfortunately"
because, in keeping with Murphy's philosophy, we didn't have those
models, (i.e. Pitney Bowes), in our compatibility test lab at the
time; nor did our Beta test sites; neither did Rockwell. (With the
incredible number of machines out there, it is impossible to perform
exhaustive testing.) Needless to say, the first customer who tried to
fax found one. If you're just using the TelePath as a modem you
wouldn't have noticed a problem.
Backorders: The modem is backordered. This is a result of the
firmware issue as well as some component availability issues. (In the
volume we order things, there are very few vendors who can keep up.)
Of course, there is also the general overload of orders. Modems will
be shipped on a 'first ordered, first sent basis' and we expect to
have the factory up to full speed very soon.
TelePath: To the best of my knowledge (and that of our legal
department), there is no such company as "TelePath," nor is this card
available under anyone else's label. It is just a name that Ted Waitt
used to refer to the modem. And since everyone in the whole company
thought it was the most brilliant marketing idea since Sam Morse
started this whole mess, it stuck. Send the modem an 'ATI3' (Identify
Manufacture) command and it will respond with "Gateway TelePath"
followed by the version number and the memory checksum.
Noise and Grounding: The TelePath does require a clean ground
(talking about your 110 outlet) to operate effectively. This is due
in part to the type of telephone line interface module that is used in
order to meet FCC, UL and foreign requirements. One of our Beta
testers was having all sorts of headaches until he found that his
ground was at 80 VRMS. This should not be an issue, since it is a
really bad (not to mention possibly illegal) idea to operate
electronic equipment without a proper ground. As far as phone line
noise is concerned, we are all familiar with the wide range of
telephone lines that you may encounter at any given time; but most
"line noise" is probably related to the grounding issue mentioned
earlier. Remember, Ma Bell never expected anyone to push 14,400 bps
through their phone system, so it shouldn't be surprising to run into
problems occasionally. There WILL be phone lines or Central Offices
that have too much noise for the modem to handle. This won't happen
often, but no one can guarantee 100% connection 100% of the time. We
will guarantee that if your PBX uses ADPCM you WILL have serious
problems with ANY modem.
Approvals: The TelePath, when installed in an approved Gateway
system, is UL listed and meets FCC parts 15 and 68. The Canadian DOC
and CSA approval process is moving forward rapidly. European
approvals are pending, but we have absolutely no idea how long the
process will take (so please, don't ask).
16C550: The C19 processor emulates a 16C450 UART and is NOT 16C550
compatible. Why? Simple -- the C19 was around before the 16C550
became such a hot item. (A rough and incomplete summary for those
that care: the 16C450 UART does not have buffers between it and the
host computer; the 16C550 does. This cuts down on the number of
interrupts required.) This does not prevent the TelePath from multi-
tasking. It will slow down your other applications more than a 16C550
would, but things should still work. However, if you're running a
80386SX, you're going to notice the difference. We have downloaded
and faxed in the background with great success on our high speed 386DX
and 486 machines.
Software: None of the TelePath issues are directly related to the
software (WinFax Pro). The engineers at Delrina (the guys who wrote
WinFax) were extremely helpful during the debug and troubleshooting
stage of this endeavor. They were able to modify one of the WinFax
files to 'work around' the firmware bug. This file is available on
the Gateway BBS at (605) 232-2224 and is named "mod.exe." The user
should just copy it over his existing "mod.exe" file. More details
are given in both the "Gory details" and "The Fix" sections later.
Supported Protocols: OK, the ad did say "try and find one we don't
support" and I admit I took a little marketing license when I wrote
that. True to form, our customers found one: Bell 208B. This is a
synchronous only mode that is used primarily on leased lines. While
it has been in use for years, it has not gained the acceptance
(outside the US government) that the CCITT standards have. There has
been a lot questions about V.32, V.32bis, V.42, V.42bis and HST. HST
is a proprietary format that can be sold only by US Robotics. No
V.32bis modem, (other than a USR Dual standard), can talk to a HST
modem at greater than 2400bps.
BBS: Our BBS continues to use US Robotics Dual standard modems
simply because many of our customers bought HST modems before we
offered a 14,400 card. Remember this: HST does not equal V.32bis!
See "Supported Protocols."
Gory details for the true modem buffs, (you guys who have nothing
else to do on a Friday night but talk to each other on networks): One
of the many parameters that the transmitting fax requires is "ST"
(Scan Time per line). This is returned to it in response to the +FDIS
command as an integer value between 0 and 7, translated into
milliseconds and passed on to the host software. The TelePath firmware
would sometimes mis-translate this value. Winfax, believing that it
was communicating with a slower fax machine, would pad its data.
Some fax machines would politely ignore these extra padding
characters; some would get quite upset about it and disconnect. This
was also dependent on whether the modem was in High or Low
resolution. In addition, software packages that ran in Class 1 would
be affected differently since the software was responsible for the
"ST" translations.
The Fix: At Gateway's request, Delrina, (the guys who wrote WinFax),
modified the code so it would transmit in Class 1 and would receive
in Class 2. This special version is available only from Gateway's
BBS. All this is transparent to the user since the software always
initializes the modem each time it sends or receives anyway.
Class 1 Vs Class 2: The main distinction between Class 1 and Class 2
involves where the negotiation is handled. In Class 1, the host
computer handles all this; while in Class 2, these tasks are
delegated to the embedded processor on the fax card. Either class can
send to either, and neither the transmitting nor the receiving fax
knows what class is at the other end. This term is somewhat
irrelevant to a stand-alone fax machine since it doesn't generally
have both an embedded controller and a microprocessor.
The Great Gateway TelePath Cover-Up: It has been rumored that all
Gateway employees have been carefully briefed regarding just what has
happened with the TelePath and how to cover-up the details with
complicated, well choreographed stories. Get real, folks! Gateway
didn't become the largest direct retailer of computers by feeding
anyone bull. But thanks for giving us credit for being that organized.
The truth is that all our resources were being used to figure out what
the problem was, what the fix was and how to explain it to Ted and to
the public.
Summary: Telecommunications is a nebulous, constantly- expanding and
somewhat confusing art form. Our rocky start will be filed under the
heading "Lessons Learned" and the sleepless nights and 70 hour work
weeks forgotten (I hope). What must be remembered is that the goal of
the TelePath is to provide an inexpensive, high performance fax/modem
-- one that would fulfill the communication needs of the majority of
our customers. This has been accomplished. Maybe soon I can move on
to another project where I don't have to listen to that irritating
negotiation sequence anymore. I have been told that some people
actually "play" with modems as a hobby (could that be true?).
"Gateway 2000 believes the Telepath is a fundamentally sound
product. We successfully Beta tested the Telepath at sites nationwide
but did not fully anticipate the wide variety of telephone and
electrical environments. Telephone and Electrical conditions differ
widely between user sites and naturally fluctuate within acceptable
norms; unfortunately, these fluctuations and their interaction has
caused the Telepath to be less than fully functional in some
situations."
"Gateway 2000 is doing a modification to the Telepath. We expect to
begin shipping the modified Telepath by the middle of June."
"The one year warranty on all Telepaths will not begin until 30 days
following shipment of the modified Telepath. This will not affect the
warranty on your Gateway PC which is one year from the date of
delivery of the PC."
"We appreciate your patience, apologize for any inconvenience and
are working hard to satisfy you. Customer satisfaction is our number
one priority. We will keep you informed on this matter."
-Gateway 2000-
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