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[unix-history] / .ref-Research-V6 / usr / sys / dmr / pc.c

#
/*
*/

/*
* PC-11 Paper tape reader/punch driver
*/

#include "../param.h"
#include "../conf.h"
#include "../user.h"

#define PCADDR  0177550

#define CLOSED  0
#define WAITING 1
#define READING 2
#define EOF     3

#define RDRENB  01
#define IENABLE 0100
#define DONE    0200
#define BUSY    04000
#define ERROR   0100000

#define PCIPRI  30
#define PCOPRI  40
#define PCOLWAT 50
#define PCOHWAT 100
#define PCIHWAT 250

struct {
       int pcrcsr;
       int pcrbuf;
       int pcpcsr;
       int pcpbuf;
};

struct clist {
       int     cc;
       int     cf;
       int     cl;
};

struct pc11 {
       int     pcstate;
       struct  clist pcin;
       struct  clist pcout;
} pc11;

pcopen(dev, flag)
{
       extern lbolt;

       if (flag==0) {
               if (pc11.pcstate!=CLOSED) {
                       u.u_error = ENXIO;
                       return;
               }
               pc11.pcstate = WAITING;
               while(pc11.pcstate==WAITING) {
                       PCADDR->pcrcsr = IENABLE|RDRENB;
                       sleep(&lbolt, PCIPRI);
               }
       } else {
               PCADDR->pcpcsr =| IENABLE;
               pcleader();
       }
}

pcclose(dev, flag)
{
       if (flag==0) {
               spl4();
               while (getc(&pc11.pcin) >= 0);
               PCADDR->pcrcsr = 0;
               pc11.pcstate = CLOSED;
               spl0();
       } else
               pcleader();
}

pcread()
{
       register int c;

       spl4();
       do {
               while ((c = getc(&pc11.pcin)) < 0) {
                       if (pc11.pcstate==EOF)
                               goto out;
                       if ((PCADDR->pcrcsr&(ERROR|BUSY|DONE))==0)
                               PCADDR->pcrcsr =| IENABLE|RDRENB;
                       sleep(&pc11.pcin, PCIPRI);
               }
       } while (passc(c)>=0);
out:
       spl0();
}

pcwrite()
{
       register int c;

       while ((c=cpass())>=0)
               pcoutput(c);
}

pcstart()
{
       register int c;

       if (PCADDR->pcpcsr&DONE && (c = getc(&pc11.pcout)) >= 0)
               PCADDR->pcpbuf = c;
}

pcrint()
{
       if (pc11.pcstate==WAITING) {
               if (PCADDR->pcrcsr&ERROR)
                       return;
               pc11.pcstate = READING;
       }
       if (pc11.pcstate==READING) {
               if (PCADDR->pcrcsr&ERROR)
                       pc11.pcstate = EOF;
               else {
                       putc(PCADDR->pcrbuf, &pc11.pcin);
                       if (pc11.pcin.cc < PCIHWAT)
                               PCADDR->pcrcsr =| IENABLE|RDRENB;
               }
               wakeup(&pc11.pcin);
       }
}

pcpint()
{

       pcstart();
       if (pc11.pcout.cc <= PCOLWAT)
               wakeup(&pc11.pcout);
}

pcoutput(c)
{
       if (PCADDR->pcpcsr&ERROR) {
               u.u_error = EIO;
               return;
       }
       if (pc11.pcout.cc >= PCOHWAT)
               sleep(&pc11.pcout, PCOPRI);
       putc(c, &pc11.pcout);
       spl4();
       pcstart();
       spl0();
}

pcleader()
{
       register int i;

       i = 100;
       do
               pcoutput(0);
       while (--i);
}