INSTALLING A
                     HIGH-SPEED MODEM


LAST WEEK I INSTALLED A PRACTICAL PERIPHERALS 9600SA MODEM ON
MY SYSTEM.  IT'S PERFORMANCE IS EXCELLENT, AND MY HAYES
SMARTMODEM 2400 IS NOW FOR SALE.  THE HAYES MODEM DELIVERED A
ZIP FILE THROUGHPUT OF ABOUT 250CPS COMPARED TO THE 9600SA
THROUGHPUT OF ABOUT 1100CPS.

AS I EXPECTED, I DIDN'T JUST PLUG IN THE 9600 BAUD MODEM AND
START DOWNLOADING!  I HAD TO RECONFIGURE BOTH THE
COMMUNICATIONS SOFTWARE AND MODEM.  ALTHOUGH RELATIVELY NEW
TO MODEM USE, I FEEL THAT SOMEONE ELSE CAN LEARN FROM MY
EXPERIENCE IN SETTING UP THE PP9600SA.  MAYBE I CAN SAVE
SOMEONE SOME TIME AND FRUSTRATION!

ALTHOUGH THE NEW MODEM WAS WORKING IN A COUPLE OF HOURS, IT
ACTUALLY TOOK ME A COUPLE OF DAYS TO GET THE PERFORMANCE UP
TO 1100CPS.

I ENDED UP READING ALL MESSAGES RELEVANT TO BOTH HIGH SPEED
COMMUNICATION AND THE MODEM IN THE EXEC BBS MESSAGE AREA, AND
THEN READING THE DOCUMENTATION WHICH CAME WITH PROCOMM PLUS
AND THE PP9600SA.  (IF ALL-ELSE FAILS.....READ THE
INSTRUCTIONS!)

THERE ARE A COUPLE OF TIPS I CAN OFFER WITHOUT GOING INTO A
LOT OF DETAIL.  (WILL BE GLAD TO BE MORE SPECIFIC IF SOMEONE
WANTS TO LEAVE A QUESTION IN THE EXEC MESSAGE AREA).

I HAVE THE PP9600SA CONFIGURED FOR 9600 BAUD AND BOTH ERROR
CORRECTION AND DATA COMPRESSION  (ERROR CONTROL VIA MODEM IS
MORE EFFICIENT THAN BY COMMUNICATION SOFTWARE).

DATA COMPRESSION DOES NOT HELP PERFORMANCE MUCH FOR ZIPPED
FILES, BUT SUPPOSEDLY HELPS FILES WHICH AREN'T COMPRESSED.
TECHNICALLY, DATA COMPRESSION SCHEMES SUCH AS MNP5 CAN
~~~SLOW~~~ TRANSMISSION OF ZIPPED FILES, BUT THE V.42BIS
CAPABILITY OF THE PP9600 RECOGNIZES COMPRESSED FILES AND
TURNS ITSELF OFF!  INCIDENTALLY, MY COMMUNICATIONS SOFTWARE
(PROCOMM PLUS) IS CONFIGURED FOR HARDWARE FLOW CONTROL "ON"
AND SOFTWARE FLOW CONTROL "OFF".

THE OTHER IMPORTANT TIP (I HAD TO "DIG" THROUGH THE DOCS FOR
THIS ONE) IS TO CONFIGURE PROCOMM PLUS FOR 19,200 BAUD
TRANSMISSION IN BOTH THE SETUP AND DIALING DIRECTORIES.  THIS
ALLOWS THE MODEM TO COMMUNICATE WITH THE COMPUTER AT A RATE
FASTER THAN THAT BETWEEN THE MODEM AND BULLETIN BOARD. THIS
SUPPOSEDLY HELPS WHEN DATA COMPRESSION IS IN EFFECT.

THERE IS ALSO A RECOMMENDATION IN THE PP9600SA OPERATING
MANUAL (OR MAYBE IT WAS ON THE BBS) TO REPLACE THE STANDARD
UART CHIP ON THE COMPUTER I/O BOARD WITH A FASTER ONE SUCH AS
AN NS16550AN, BUT I HAVEN'T DONE THAT YET. THE STANDARD 16450
UART SEEMS TO WORK FINE, BUT I WILL TRY THE 16550 WHEN IT
ARRIVES.

UPON RECOMMENDATION OF THE PRACTICAL PERIPHERALS MANUAL I AM
USING YMODEM-G STREAMING PROTOCOL.  COMPARED TO OTHER
PROTOCOLS IT SEEMS TO BE THE FASTEST WITH THE SETUP ABOVE.

IN CONCLUSION, I WOULD HIGHLY RECOMMEND THE 9600SA WITHOUT
RESERVATION; IT PERFORMS EXACTLY AS ADVERTISED.  THE
OPERATING MANUAL IS EVEN DECENT!  THE ONLY GENERALLY
COMPATIBLE MODEM THAT I KNOW OF WHICH IS SUBSTANTIALLY FASTER
IS THE US ROBOTICS DUAL STANDARD MODEM WITH HST, BUT IT COMES
WITH A HEFTY PRICE TAG!!!

INCIDENTALLY, I ALSO USE THE PP9600SA ON COMPUSERVE AT 2400
BAUD WITH ERROR CORRECTION AND FIND IT FULLY COMPATIBLE.

I HAVE NO CONNECTION WITH ANY MODEM OR COMPUTER VENDOR OR
ORGANIZATION, ONLY AN AMATEUR FASCINATION WITH THIS RAPIDLY
EVOLVING, AND HIGHLY POTENTIAL TECHNOLOGY OF DIGITAL
COMMUNICATION.  I WOULD BE GLAD TO CHAT AT LENGTH WITH ANYONE
ON THE SUBJECT.


                                   DWIGHT L. TURNER

                                     MAY 11, 1991