COM3/4 and 14400 BAUD in Quick Basic?

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3 total messages Started by Michael Burger Mon, 25 Jan 1993 23:30

#446

Author: Michael Burger
Date: Mon, 25 Jan 1993 23:30

13 lines
1295 bytes

The subject line says it all.  I need to know if there are any tricks or
add ons to have QuickBasic recognize COM3 and COM4 plus transmit in 14400
BAUD.


*******************************************************************************
*  Mike Burger                    *  The redhead accross the aisle.           *
*  mmb@lamar.colostate.edu        *  --A student responding to the question   *
*  A Beginning Computing TA Stud  *    "what will I remember from Beginning   *
*  over 500 students served       *     Computing after I graduate."          *
*******************************************************************************
*      University of Michigan - 1990  --  Colorado State University - 199?    *
*******************************************************************************

Re: COM3/4 and 14400 BAUD in Quick Basic?

#449

Author: Ronal Thompson
Date: Tue, 26 Jan 1993 21:12

56 lines
2018 bytes

mmb@lamar.ColoState.EDU (Michael Burger) writes:

>The subject line says it all.  I need to know if there are any tricks or
>add ons to have QuickBasic recognize COM3 and COM4 plus transmit in 14400
>BAUD.

This sub program writes DIRECTLY to the uart.

sets is the speed you want the uart set to.
setp is the port.
you MUST open the port FIRST (usually at 9600) then call this routine

The speec that the uart ACTUALLY gets set to is returned in speed(setp)
this allows you to compare what you want to what you got.
(whatta ya mean I can't set the uart to 113.912 baud?!?!)

SUB BaudSet (sets, setp)

SHARED Speed()

  IF setp = 1 THEN offset = &H3F0
  IF setp = 2 THEN offset = &H2F0
  IF setp = 3 THEN offset = &H3E0
  IF setp = 4 THEN offset = &H2E0

  Urate = INT(XTAL / (16 * sets))
  SPEED.LSB = Urate AND &HFF
  IF Urate AND &HFF00 <> 0 THEN
     SPEED.MSB = (Urate AND &HFF00) / 256
  ELSE
     SPEED.MSB = 0
  END IF

  a = INP(offset + &HB)               'READ DLAB BYTE
  a = a OR &H80                       'TURN IT ON
  OUT (offset + &HB), a               'WRITE IT
  OUT (offset + &H8), SPEED.LSB       'LOAD LSB
  OUT (offset + &H9), SPEED.MSB       'LOAD MSB
  a = a AND &H7F                      'TURN DLAB OFF
  OUT (offset + &HB), a               'WRITE IT

  Speed(setp) = INT(XTAL / (16 * Urate))

END SUB

ronal@telebit.com                These ain't no opinions but my own!
R.THOMPSON65  GEnie                                     
MJWG99A  Prodigy    and remember,  what you think of me is none of my business

Re: COM3/4 and 14400 BAUD in Quick Basic?

#450

Author: Ronal Thompson
Date: Wed, 27 Jan 1993 05:58

19 lines
1274 bytes

>This sub program writes DIRECTLY to the uart.

>sets is the speed you want the uart set to.
>setp is the port.
>you MUST open the port FIRST (usually at 9600) then call this routine


>The speec that the uart ACTUALLY gets set to is returned in speed(setp)
>this allows you to compare what you want to what you got.
>(whatta ya mean I can't set the uart to 113.912 baud?!?!)

The constant xtal should be set to 1843200. This is the crystal
driving the uart. If you use an external frequency source to 
vary the uart speed, or to reach normally unobtainable rates, 
then change this constant accordingly

ronal@telebit.com                These ain't no opinions but my own!
R.THOMPSON65  GEnie                                     
MJWG99A  Prodigy    and remember,  what you think of me is none of my business

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