Shareware Grab Bag/Shareware Grab Bag.iso/090/ciarnv85.arc/HOST.4TH

Text File | 1986-04-08 | 4KB | 91 lines

              ( XECOM MODEM DEMO AND TERMINAL EMULATOR 1.00 )

                  ( The name of this file is HOST.4TH. )

( The main loop of the Host computer terminal emulation is called HOST. )
( It is in the last segment of this program: H2.4TH.                   )

HEX
C" XE1" XE1      ( name of device. see device driver source listing )
: XO XE1 2 FOPEN FHNDL ! ; ( opens XE1 for read and write )
VARIABLE BUFF2 40 ALLOT  ( buffer to hold bytes returned by function calls )

( The following 4 routines are the basic data, control/status read/write )
( functions. DA@ returns one data byte on the stack. DA! takes one byte  )
( from the stack and stores it in the data port. CT@ returns the status  )
( byte on the stack. CT! takes one byte from the stack and stores it in  )
( the control port. These routines are coded in assembler according to   )
( FORTH assembler conventions and use DOS function calls.         )

( Note that you may simply poll the status register until the receiver   )
( ready bit is on and then fetch a byte from location 2f8, data port, as )
( an alternate method. Or similarly poll the status register, 2f9, until )
( transmitter ready bit is on, and then store a data byte at 2f8.        )
( This method is used in the voice routine called SAY. See VDICT0.4TH.   )

CODE DA@ DX, DX XOR DX PUSH DX, SP MOV CX, # 0001 MOV
      BX, FHNDL MOV AX, # 3F00 MOV INT21
      NEXT JMP END-CODE
CODE CT@ DX, DX XOR DX PUSH DX, SP MOV CX, # 0001 MOV
      BX, FHNDL MOV AX, # 4402 MOV INT21 AX, BUFF2 MOV
      NEXT JMP END-CODE
CODE CT! DX, SP MOV CX, # 0001 MOV
      BX, FHNDL MOV AX, # 4403 MOV INT21
      DX POP NEXT JMP END-CODE
CODE DA! DX, SP MOV CX, # 0001 MOV
      BX, FHNDL MOV AX, # 4000 MOV INT21
      DX POP NEXT JMP END-CODE


( The following routines are for line analysis calculations. )
DECIMAL
CREATE K 2 ALLOT
CREATE LEV 2 ALLOT
CREATE TBASE 2 ALLOT   ( VARIABLE TO HOLD NUMBER BASE e.g. HEX )
: D.0 BASE @ TBASE ! DECIMAL 10 >R   ( outputs a double number with 3 ...)
   SWAP OVER DABS <# #S ROT SIGN #>  (  decimal places.                  )
   R> OVER - SPACES TYPE TBASE @ BASE ! ;
: D.1 BASE @ TBASE ! DECIMAL 10 >R  ( outputs a double number w/1 decimal )
   SWAP OVER DABS <# # 46 HOLD #S ROT SIGN #>
   R> OVER - SPACES TYPE TBASE @ BASE ! ;
: CU.000 ( D -- D ( CUBES A NUMBER THAT IS TIMES 1000 )
  DDUP DDUP DROP 1000 M*/ DSWAP DROP 1000 M*/ ;
: 20LOG10N 0 K !  ( CALCULATES 20 LOG10 OF A DOUBLE )
    ( PRECISION NUMBER * 1000 AND RETURNS THE SAME )
   BEGIN DDUP 2.000 D> WHILE 6 K +! 2 M/MOD
     ROT DROP REPEAT
   DDUP CU.000 1.000 D- DSWAP 1.000 D+
   CU.000
   DROP 1000 SWAP M*/
   23 1 M*/ K @ 1000 M* D+ ; ( D.000 )
: S/N_DB ( SIGNAL TO NOISE IN DB ) ."                SIGNAL/NOISE RATIO IS    "   LEV @ 3 < IF ."       > 45  dB "
   ELSE LEV @ 255 = IF ."        < 4  dB "
                    ELSE 420.800 LEV @ M/MOD ROT DROP
                     20LOG10N .500 D+ 1 1000 M*/ D.0
                     ."   dB " THEN THEN ;
HEX
: SIGNEX DUP 7F > IF FF00 OR THEN ;
DECIMAL
CREATE DEV 2 ALLOT
: FREQ_DEV ."           CARRIER FREQUENCY ERROR IS    "
      7372800. 1000 3314 DEV @ SIGNEX
    - M*/ 2225.000 D- .50 D+ 1 100 M*/ D.1 ."   Hz " ;
CREATE NN 2 ALLOT
: SLCALC NN @ DUP M* 1000 19391 M*/ NN @ 1000 M* 20LOG10N ( calculates ...)
    D- 4.100 D- .500 D+ 1 1000 M*/ D.0 ;                  ( signal level. )
: SIG_LEV ."            RECEIVED CARRIER LEVEL IS    "
    NN @ 3 < IF ."      > -10 dBm "
             ELSE NN @ 255 = IF ."      < -40 dBm "
                             ELSE SLCALC ."  dBm "
                             THEN
             THEN ;
HEX
( End of line analysis calculations. )

==> B:H1.4TH