RS232.DOC

NOTES ON USING THE RS232.EXE COM PORT DEBUGGER.

INTERFACEING TO THE RS232 (COM) PORTS ON ANY COMPUTER HAS ALLWAYS BEEN A
PROBLEM BECAUSE THERE ARE TWO TYPES OF COM PORTS, TERMINAL (DTE - DATA
TERMINAL EQUIPMENT) AND MODEM (DCE - DATA COMMUNICATIONS EQUIPMENT) AND
UNFORTUNATELY NOT EVERY MANUFACTURER STRICTLY ADHERES TO THE RS232 STANDARD.

THE RS232 PORTS ON THE ALL VERSIONS OF THE PC ARE GENERALLY
DTE TYPE UNLESS YOU HAVE ONE OF THE BOARDS THAT ALLOWS YOU TO CONFIGURE THE
PORT AS A DCE PORT. YOU WILL HAVE TO DETERMINE WHAT TYPE OF PORT YOU HAVE.
IF YOU HAVE AN RS232 (COM) PORT CONFIGURED AS A DCE PORT, RS232.EXE IN ITS
PRESENT CONFIGURATION WILL NOT TEST IT.

THIS PROGRAM WAS WRITTEN TO HELP YOU FIGURE OUT IF ANYTHING WRONG WITH YOUR

RS232.EXE IS SELF DOCUMENTING IN THE MENUS. THE ONLY THING THE AVERAGE USER
MAY NOT UNDERSTAND IS THE ERROR MESSAGES AND THE USE OF THE PORT DEBUGGER.
TO UNDERSTAND THESE IT IS HELPFUL TO HAVE A DATA SHEET FOR THE UART USED
ON THE PC RS232 COM PORTS. THIS IS AVAILABLE FROM THE VARIOUS SEMICONDUCTOR
MANUFACTURERS OR IF YOU REGISTER YOUR COPY YOU WILL BE SENT A COPY OF THE
APPROPRIATE DATA SHEET. TO USE THE PORT DEBUGGER IT IS HELPFUL IF YOU HAVE
USED A MACHINE LANGUAGE DEBUGGER IN THE PAST, SINCE THE OPERATION OF THE PORT
DEBUGGER IS SIMILAR.

TO USE RS232.EXE YOU MUST CONNECT A TEST PLUG TO THE PORT YOU ARE TESTING.
OR A NULL MODEM CABLE THAT IS CONNECTED BETWEEN THE TWO COM PORTS ON YOUR
SYSTEM. THE WIREING DIAGRAM FOR THE NULL MODEM CABLE AND THE TEST PLUGS
IS GIVEN IN THE PROGRAM.

WHILE DESIGNING THIS PROGRAM I FOUND A BUG IN THE PHOENIX BIOS VER 3.07
THAT I HAD IN MY PCAT CLONE. CHANGING THE BIOS TO VER 3.10 FIXED TH PROBLEM.
THE PROBLEM WAS THAT COM2 COULD NOT TALK TO ITSELF NOR COULD COM1 TALK TO COM2.
THE RECEIVED MESSAGE AT COM2 WAS ALWAYS GARBAGE.

REGISTRATION FOR YOUR COPY OF RS232.EXE IS AVAILABLE FOR $10.00. WHEN YOU
REGISTER, YOU WILL BE SENT A COPY OF THE DATA SHEET FOR THE UART USED IN ALL
VERSIONS OF THE PC. THE UART IN THE PCXT AND PCAT ARE DIFFERENT BUT THE
REGISTERS IN THE TWO UARTS OPERATE EXACTLY THE SAME, OTHERWISE
COMMUNICATIONS SOFTWARE FOR THE PC AND PCXT COULD NOT BE USED ON THE PCAT.

IF YOU ARE NOT MECHANICALLY INCLINED YOU MAY ALSO PURCHASE READY MADE TEST
PLUGS AND OR NULL MODEM CABLES AT THE TIME YOU REGISTER.



RS232 PORT AND AT LEAST ELIMINATE THAT ONE POTENTIAL PROBLEM SOURCE.
SHAREWARE REGISTRATION FORM FOR RS232.EXE

K. M. BRANSCOME
368 N. WALNUT GROVE RD.
MIDLOTHIAN, TEXAS 76065

REGISTERED TO:

NAME ____________________________

STREET ADDRESS ____________________________

CITY, STATE ZIP _______________________, ________ ________

PLEASE CHECK ITEMS DESIRED:
[X] (1) REGISTRATION RECEIVE UART DATA SHEET -------- $10.00
[ ] (2) 25 PIN TEST PLUG ------------------------------ $10.00
[ ] (3) 9 PIN TEST PLUG ------------------------------ $10.00
[ ] (4) BOTH 25 PIN AND 9 PIN TEST PLUG --------------- $15.00
[ ] (5) 25 PIN TO 25 PIN 1 FOOT NULL MODEM TEST CABLE - $15.00
[ ] (6) 25 PIN TO 9 PIN 1 FOOT NULL MODEM TEST CABLE - $15.00
[ ] (7) 9 PIN TO 9 PIN 1 FOOT NULL MODEM TEST CABLE - $15.00
NOTE - THE NULL MODEM TEST CABLES ABOVE CAN BE USED WITH A
STANDARD MODEM CABLE IF GREATER LENGTH IS REQUIRED.

THE TOTAL AMOUNT DUE IS ------------------------------- $__________
MAKE CHECK OR MONEY ORDER PAYABLE TO K. M. BRANSCOME

SEND REGISTRATION FORM AND REMITTANCE TO :

K. M. BRANSCOME
368 N. WALNUT GROVE RD.
MIDLOTHIAN, TEXAS 76065

DISCLAIMER - RS232.EXE IS PROVIDED UNDER THE SHAREWARE CONCEPT.
K. M. BRANSCOME WILL NOT BE RESPONSIBLE FOR ANY DAMAGES OR
LOSS OF DATA THAT MAY RESULT FROM THE USE OF THIS PROGRAM. THE
USER TAKES SOLE RESPONSIBILITY WHEN USING THIS PROGRAM.

PLEASE SIGN AND DATE THE REGISTRATION FORM BELOW.

SIGNATURE _______________________________ DATE ________________


REVISION NUMBER OF RS232.EXE THAT YOU HAVE __________________