Unit YAsync; { Version 1.4 }

"Yet another" set of Async routines.  This unit supports
concurrent use of one to four 8250 Asynchronous communications
ports with transmit and receive buffer interrupt support and
flexible handshaking options at the interrupt level.  Upon
program termination, all open ports are closed and interrupt
vectors returned to their former values.

Copyright 1987 by Edwin Floyd [76067,747]
                  4210 Pickering Dr.
                  Columbus, GA 31907
                  (404) 563 - 9915

All rights reserved; non-commercial use Ok.

Update History

1.0 10-12-87 E. Floyd, Initial implementation and testing
             complete
1.1 11-22-87 E. Floyd, Added handshaking options, changed name to
             YAsync
1.2 11-29-87 E. Floyd, Separated handshaking options, changed
             irpt handler
1.3 12-19-87 E. Floyd, Removed polling support, changed buffer
             spec.
1.4 12-21-87 E. Floyd, Documented for upload to C'Serv, added
             buflen funcs

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

Program YasDemo;

YasDemo Version 1.1 - Quick and dirty, multiple async port demo
for YASYNC.

Run like this:

  yasdemo nedpshbbbbb [...]

Where: n   = Serial port number, 1..4
       e   = Echo option, E=Echo keyboard on screen (HDX), N=No
             Echo (FDX)
       d   = Data bits, 5..8
       p   = Parity, E,O,N,0 or 1
       s   = Stop bits, 1 or 2
       h   = Handshaking: N=None, D=Dtr/Dsr, C=Rts/Cts,
             X=Xon/Xoff
       b.. = Data rate, bits per second

Example:

  yasdemo 3N7E2X1200 1E8N1N9600 2E8N1N9600

Translation - Establish three windows:

  1. COM3, No Echo, 7 bits, even parity, 2 stop bits, Xon/Xoff
     handshaking, 1200 Bps.

  2. COM1, Echo, 8 bits, no parity, 1 stop bit, no handshaking,
     9600 Bps.

  3. COM2, Echo, 8 bits, no parity, 1 stop bit, no handshaking,
     9600 Bps.

Note.. Some hardware serial port configurations preclude
concurrent use of more than one serial port at a time.  In
particular, two ports which share an interrupt may "fight" over
the irq line if not connected through appropriate logic so either
may trigger the interrupt independently.  This sometimes results
in one port appearing to function only when interrupts occur
regularly on the other port.  This is a sign of incorrect
hardware design or installation.

The format of the control line was chosen for convenience of
interprtation, not ease of use.  If anyone feels the urge to
correct this deficiency, please don't hesitate.

By: Edwin T. Floyd [76067,747]
    Hughston Sports Medicine Foundation
    P.O. Box 9517
    Columbus, GA 31995
    (404) 324-6074

This demo program is contributed to the public domain.

12-20-87 E. Floyd - Version 1.0
12-21-87 E. Floyd - V 1.1 Added Echo option, documented for
         C'Serv upload