* P COMMAND FOR SK*DOS
* SUBSTITUTES PRINTER DRIVER FOR NORMAL OUTCH OUTPUT
* COPYRIGHT (C) 1984 BY PETER A. STARK

* DOS EQUATES

SPOOLF  EQU    $CCFC
PSTRNG  EQU    $CD1E
WARMST  EQU    $CD03
OUTCH   EQU    $CD0F
RENTER  EQU    $CD06
SPORT   EQU    $E000     SERIAL PORT ADDRESS

* PROGRAM

        ORG    $C100
START   BRA    START1

        FCB    1         VERSION 1

START1  TST    SPOOLF    TEST SPOOLING FLAG
        BNE    NGSPOO    NO GOOD IF SPOOLING
        JSR    PRINIT    INITIALIZE PRINTER
        LDX    #PROUT    POINT TO PRINTER ROUTINE
        STX    OUTCH+1   PUT INTO OUTCH VECTOR
        JMP    RENTER    RETURN TO SK*DOS

* ERROR PROCESSING

NGSPOO  LDX    #SPOMSG   PRINT "NOT ALLOWED ..."
        JSR    PSTRNG
        JMP    WARMST    AND QUIT
SPOMSG  FCC    'NOT ALLOWED WHILE SPOOLING',4

* SERIAL PRINTER ROUTINES

* INITIALIZE ACIA
        ORG    $CCC0
PRINIT  LDA    #$13
        STA    SPORT     INITIALIZE ACIA
        LDA    #$15      8 DATA BITS, 1 STOP, 16X CLOCK
        STA    SPORT
        RTS

* CHECK PRINTER STATUS
        ORG    $CCD8
PRCHEK  PSHS   A
        LDA    SPORT     ACIA STATUS REGISTER
        ASRA
        ASRA             MOVE TDRE BIT INTO CARRY
        PULS   A,PC      RESTORE A AND RETURN

* OUTPUT CHARACTER FROM A TO PRINTER
        ORG    $CCE4
PROUT   BSR    PRCHEK    CHECK IF READY
        BCC    PROUT     REPEAT IF NOT READY
        STA    SPORT+1   THEN OUTPUT CHARACTER
        RTS              AND RETURN

        END    START