#5479 - Part 10 - Delplanche

Il paraît que si vous n'avez pas un PowerPC ou un Mac AV, cela ne sert à rien d'utiliser un modem V34 à 28800 bauds, les ports série de votre Mac ne supportent pas plus de 14400 bauds + compression.

Comment faire pour accélérer le port série ?

Connaissez-vous le boîtier SCSI qui ajoute 2 ports série haute vitesse à n'importe quel Mac via le port SCSI ? Distribué en Belgique ?

*** Qui peut aider notre ami Dominique ?
S'il existe une solution software, elle est encore et toujours seulement valable pour les Macs AV et les Power Mac: Serial Speed est un document Tableau de Bord qui accélère le port série et dont une version shareware se trouve dans le dossier Telecom du BBS Mactivity.
Voici un extrait de son fichier ReadMe:

Get more performance from your Power Macintosh and Macintosh AV with SerialSpeed 230!

SerialSpeed 230: Boost your serial port throughput to 115,000 bps or
230,000 bps, no additional hardware required, compatible with your
existing applications

SerialSpeed 230 is a control panel and system extension. It works with the
enhanced serial driver (on Power Macintosh and Macintosh "AV class"
computers) to boost your serial port speed. Your existing communication
applications that operate at 57.6Kbps will use SerialSpeed 230 to speed their
operations; they'll talk to your serial devices 200% or 400% faster than before!

SerialSpeed 230 is Shareware: try it before you buy, inexpensive and
easy to purchase

You get a free 14-day trial period to evaluate SerialSpeed 230; test its
compatibility with your computer, applications, and serial devices. Experience
the increased performance of SerialSpeed 230 for yourself! If you choose to
become a registered user, the cost is only US $25 per copy. You may register by
mail or electronic mail (using the NetCash electronic payment system; see
below for details). Registered users receive free technical support, upgrade
notices, and that fuzzy warm feeling you get from knowing you have done
the Right Thing.

System Requirements

You need:

* A Power Macintosh or "AV" Macintosh (i.e. Quadra AV, Centris AV)
* A serial device that can operate at 115Kbps or 230Kbps, for example
a V.FC or V.34 modem. (Note: most V.32(bis) modems do not support
115Kbps or 230Kbps operation!)
* Application software that is normally used at the speed of 57.6Kbps

The first step:

Let's say you have a telecommunications program like ZTerm and a V.34
modem. First you need to set everything up so it works reliably at 57.6Kbps.
This means using the proper hardware handshaking serial cable, setting
hardware handshake mode on your modem and in your communications
program, setting, 57.6Kbps port speed, etc.

Instructions on how to do this will vary depending on what kind of modem
and application software you are using, so I can't provide more than the most
general guidelines. I recommend that you set up your modem so that it will
give the most detailed feedback on your connections (i.e. not only report
CARRIER 28800, but also CONNECT 57600 and COMPRESSION V.42, etc.)
Consult your modem manual for details. Once you have your serial
connection working at 57.6Kbps, it's time to install SerialSpeed 230 and get
turbocharged!

Installation Instructions
Easy.

SerialSpeed 230 is distributed as:
a Self Extracting Archive File (.SEA)
or a Stuffit Archive File (.SIT)
or a BinHex Archive File (.HQX)

Use BinHex or Stuffit(TM) to convert the BinHex Archive File or Stuffit
Archive file into the SerialSpeed 230 folder.

Or simply double-click on the Self Extracting Archive file to create the
SerialSpeed 230 folder.

Copy the SerialSpeed 230 Control Panel to your Control Panels folder.

Open the SerialSpeed 230 Control Panel.

The control panel gives you the opportunity to set which ports will be
accelerated, and to what speed. You have three choices for each port:

* No Change - SerialSpeed will not speed up this port.

* 230,000 BPS - SerialSpeed will accelerate this port to 230Kbps

* 115,000 BPS - SerialSpeed will accelerate this port to 115Kbps

The default settings are:

* Modem port: 230,000 BPS
* Printer port: No Change

You can also choose to check the serial driver for compatibility when your
computer starts up. I highly recommend you leave this option ON for now.

Once you have chosen the appropriate settings for your system, close the
control panel and restart your computer.

Starting up with SerialSpeed 230

SerialSpeed 230 checks during startup to make sure your computer can
support its capabilities.

If everything checks out OK, SerialSpeed displays this icon.

If something went wrong, SerialSpeed displays an "X" in the icon.

You can prevent SerialSpeed 230 from loading by holding down the Shift key
during startup. SerialSpeed will display the "X" icon to indicate it did not
load.

Startup Messages

Once the Finder has loaded, you may see one of several dialog boxes.

The first one is normal during the trial period, it indicates that you have not
registered the product.

"This copy of SerialSpeed 230 is unregistered. You may try SerialSpeed 230
free for 14 days, then you must register your copy to continue using it. Open
the SerialSpeed 230 control panel for registration instructions"

The second dialog indicates that your system cannot support SerialSpeed 230.

"SerialSpeed 230 requires the DMA serial driver to operate properly. Only
certain Macintosh models support the DMA serial driver; please consult the
SerialSpeed 230 documentation for details."

SerialSpeed 230 requires an enhanced serial driver from Apple in order to
operate. This DMA driver works faster and with less demand on the
Macintosh CPU than the older, interrupt driven driver. Unfortunately, the
enhanced driver is only available on the Power Macintosh, Quadra AV, and
other "AV" Macintoshes. If you get this dialog, you'll have to remove
SerialSpeed 230 from your system by dragging the Control Panel to the trash
can. Sorry! See the Compatibility Notes/FAQ (below) for more details.

The third dialog indicates that SerialSpeed was not able to open the serial port
during startup.

"SerialSpeed 230 could not open a serial port at startup because it was in use
by another System Extension. To fix this problem, turn off "Check serial
driver at startup" in the SerialSpeed 230 Control Panel, then restart your
Macintosh.

This is a common problem for users who have an Epson Color Stylus printer
and the "ASFU Fixer" System Extension installed. If you see this dialog, you
can solve the problem by following the above steps.

Using SerialSpeed 230

Transparent Operation

SerialSpeed 230 is activated automatically on whichever serial ports you
enabled in the Control Panel. Whenever an application opens the "enabled"
serial port at a speed of 57.6Kbps signals SerialSpeed 230 to kick in and double
or quadruple the port speed! This means you can configure any application
for 57.6Kbps and use it as you normally would, but 2 or 4 times faster.

Configure your applications for 57.6Kbps

If you've had a high speed modem for awhile, you've probably done this
already. It's important that you set each application to communicate at
57.6Kbps port speed because SerialSpeed will not kick in at a lower port speed
(this is so you can use selected applications at a lower speed, say 38.4Kbps, if
the need arises.)

How to get the highest performance

SerialSpeed 230 boosts the speed of the connection between the Macintosh
and your serial device (i.e. modem.) It does not boost the speed of your serial
device or your application program. It is critically important to make sure
these other components are operating at peak performance. Here are some
tips:

Make sure data compression is enabled on your modem. If your modem is
not sending compressed data, it's sending at its basic rate of 14.4Kbps or
28.8Kbps and you won't see any speed improvement. Most V.34 modems will
transmit compressed data to your computer at 115Kbps, and some V.34
modems (i.e. Hayes, AT&T) will transmit compressed data at a full 230Kbps!

Use efficient file transfer programs like ZMODEM. These will transmit larger,
more compressible chunks of data and allow your modem to operate at a
higher speed. Older protocols like Kermit and XMODEM send small chunks
of data and performance suffers as a result.

Also, remember that all communication applications are not created equal.
Consider upgrading to a Power Mac native application.

Make sure the computer on the other end is sending data at rates of 115Kbps
or 230Kbps. Even if the remote system has a V.34 modem, this is no guarantee
that it is sending data faster than 57.6Kbps. Most IBM PC based systems can
send you data at 115Kbps or 230Kbps. Most UNIX(tm) systems can also send
data at these high speeds. If the system on the other end is a Macintosh, you
might suggest to the system's owner that they invest in a copy of SerialSpeed
to ensure that they are providing the maximum speed for their customers...

Consider new technology like ISDN Modems that can send and receive data
at 64Kbps or 128Kbps (and with compression, much higher!) These offer
tremendous speed increases. SerialSpeed 230 will help you get the most from
this technology.

------------------------------

Compatibility Notes/FAQ

What programs are known to work with SerialSpeed 230?

Zterm 0.85
MicroPhone Pro
Apple Remote Access Client 2.0
VersaTerm (using the standard serial drivers)
eWorld Client 1.1b2
TeleFinder Pro 2.2.3
MacPPP 2.0.x

* more to come; tell me about your success stories!

What programs are known to fail?

* tell me about other failures and I'll try to fix them!

What modems are known to work with SerialSpeed 230?

Practical Peripherals PM288MT II V.34
Hayes Optima 28.8 V.34 V.FC
SupraFAXModem 288 only at 115Kbps

(almost every V.34 or V.FC modems will work.)

* tell me...

What modems are known to fail?

Any modem that does not support 115Kbps or 230Kbps operation. (this
includes most V.32 and V32bis modems.)

Will SerialSpeed 230 work with my GeoPort?

The answer is "maybe." Any software that sees the GeoPort as a modem in
the modem port or printer port (i.e. the software looks specifically for ".aIn",
".aOut", ".bIn" or ".bOut" serial drivers) will activate SerialSpeed 230
properly. I don't own a GeoPort but I understand the current software only
operates at 14.4Kbps. If so, you will achieve a limited speedup at best. If and
when Apple releases a 28.8Kbps GeoPort driver, you will see dramatic
speedups in your software by using SerialSpeed. I'd appreciate reports from
GeoPort users on your successes & failures.

Why won't SerialSpeed 230 work with my SupraFAXModem 288?

It will. But you must use SerialSpeed at 115Kbps, not 230Kbps. This modem
does not support 230Kbps operation.

Will SerialSpeed 230 accelerate programs that use the
Communications Toolbox drivers?

Probably not. (Not yet, anyway.) This is because SerialSpeed is activated by
calls to the standard serial drivers, not the Communications Toolbox drivers.
Many programs, like MicroPhone Pro, allow you to choose which drivers to
use. This limitation may be addressed in a future release, but until then, use
the standard serial drivers rather than the Communications Toolbox drivers
whenever possible.

What are the limitations of the Printer Port?

Apple documentation states that the printer port is handled at a lower
priority than the modem port (i.e. incoming data is handled first from the
modem port) so high speed operation on the printer port is more risky.

Furthermore, documentation for the Quadra 840AV/660AV states that DMA
operation is not enabled for receiving information on the printer port. I do
not know if this holds true for Power Macintosh computers.

These two points lead me to suggest that, if you have the option, you should
use your modem port for high speed operation instead of your printer port.

If you have problems using the printer port at high speeds, and you switch
your device to the modem port and find that it works on the modem port,
this is probably the culprit.

However, I have heard many success stories of individuals who are using
their printer ports at 230Kbps speed every day, with no problems. So it's
certainly worth trying.

Can I use SerialSpeed 230 to speed up my serial printer?

Probably not, but it can't hurt to try. Apple printers are the only printers I
know that support 230Kbps or 115Kbps serial operation. In fact, Apple's serial
printers already use 230Kbps serial transfers, so SerialSpeed won't speed them
up any further. Other manufacturers may or may not support high speed
operation, and if they do, you're in luck. Tell me your success stories...

What is the "DMA Serial Driver" and why do I need it?

Since the first Macintosh, the serial ports have used an interrupt-driven serial
driver. This driver takes valuable CPU time to handle every character that is
received or sent through the serial ports. At high speeds, the interrupt-driven
serial driver gets completely swamped and starts to lose information.
57.6Kbps is about the best you can do with the interrupt-driven serial driver
for bidirectional data transfers (the kind you use with modem programs.) You
can go to 230Kbps in one direction (send) but not receive. That is what the
Apple printer drivers do, because you're mostly sending data to a printer. But
it won't work for a modem because you often use it to receive data.

The AppleTalk drivers achieve 230Kbps on all Macintoshes because they
completely take over your computer when they are running, something that
a modem program cannot do. They are "synchronous drivers" as opposed to
the "asynchronous" drivers used by modem programs.

The DMA serial driver makes use of special, improved hardware present on
the "AV" and Power Macintosh. This hardware allows information to flow
straight from the serial ports into memory with little or no work on the
CPU's part. This means that the serial ports can support much higher speeds
in both directions, such as 115Kbps or 230Kbps. Hooray!

Will they ever release a DMA Serial Driver for my older Mac?

No, because your serial port hardware does not support DMA transfers. The
Mac IIfx does support DMA transfers, but it is unclear whether Apple will
attempt to support this discontinued model in a future software release.
Apple promises a new serial port driver architecture as part of their next-
generation system software (System 8?) Will it work on your Mac? Your
guess is as good as mine...

I can force SerialSpeed 230 to load on my older Mac by turning off
the "Check serial driver at startup" option. Why shouldn't I do this?

If you happen to have a printer that supports 115Kbps operation or 230Kbps
operation, then SerialSpeed 230 may work to speed up your printer, even if
you have an older Mac.

But for all the reasons stated above, I will not provide any support to users
who insist on using SerialSpeed and modems on their older, non-DMA serial
driver Macs. If you try it, it'll appear to work... until you try receiving large
quantities of data. For example, the first time you try a ZMODEM receive.
Then you'll get tons of garbage and the transfer will fail. (Sigh.) I'd make it
work if I could.

My communications software has built-in support for 115Kbps and
230Kbps. Do I need SerialSpeed?

Not for those products. For example, ZTerm 1.0b3 and newer versions of
MacPPP have built-in support for these higher speeds. SerialSpeed 230 will
coexist happily with these programs, and won't harm their operation.
SerialSpeed is primarily useful for programs that do not have built-in support
for 230Kbps or 115Kbps operation.

Are you doing something evil to achieve these high speeds?

Well, yes and no. 230Kbps operation has been "blessed" by Apple; they've
documented the API and will tell developers how to do it (send an AppleLink
to DEVSUPPORT).

115Kbps operation is an entirely different story. Apple won't tell you how to
do it, they don't publish an API on how to do it, but they will drop hints. I
used these hints, plus some tips from the helpful Internet Mac developer
community to write the code. In a nutshell, the 115Kbps code writes directly
to the serial chip's onboard registers. This is a definite no-no in Apple's
compatibility guidelines. It works on all the machines I've tested, and it
certainly won't harm anything. But there is no guarantee it will work with
future versions of system software or future Macintoshes. C'est la vie... >>

© Mactivity Estonia 1996