BBS: Inland Empire Archive
Date: 10-13-92 (23:07)             Number: 351
From: JERRY HUNTER                 Refer#: NONE
  To: KENNY BINGHAM                 Recvd: NO  
Subj: Why PATCH DTR?                 Conf: (2) Quik_Bas
 > So if I understand you correctly, I could away with
 > something like this:
 >  DEF SEG=0
 >  PortAddr%=&H3F8
 >  CLOSE #1
 >  OUT Port Addr% + 4, 3
 >  Open "COM1:" For input as #1

 > Where the last statement allows me to read input from the
 > screen? Also You mentioned problems with 8088's? How about
 > 8088's with NEC V20 chips in them?

Well, I'm not quite clear * how * that "last statement allows you to read
input from the screen", since you're opening for input from
the COM1: port (modem, mouse, or other RS232c device).

This little trinket allows you to slam the DTR line high to
keep the modem's Carrier Detect (CD) signal high even
though you exit
the program or run to another program. She basically saves the
carrier detect signal from dropping as it normally would after
a CLOSE statement is issued. This eliminates the need for a
"PATCH" to the QB libraries to obtain the same end result.

Once you've RUN the other program, or are ready to reopen the port, you may
simply OPEN the COMx: port as you normally would, and
immediately resume communications.

Bear in mind that if you're working with COM2:, COM3: or
COM4:, the PortAddr% needs to be modified to &H2F8, &H3E8,
or &H2E8, respectively.

Perhaps if you could clarify your question, I could assist more effectively.

Jerry Hunter

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