usr/sys/param.h

/*
 * tunable variables
 */

#define NBUF    15              /* size of buffer cache */
#define NINODE  100             /* number of in core inodes */
#define NFILE   100             /* number of in core file structures */
#define NMOUNT  5               /* number of mountable file systems */
#define NEXEC   3               /* number of simultaneous exec's */
#define MAXMEM  (64*32)         /* max core per process - first # is Kw */
#define SSIZE   20              /* initial stack size (*64 bytes) */
#define SINCR   20              /* increment of stack (*64 bytes) */
#define NOFILE  15              /* max open files per process */
#define CANBSIZ 256             /* max size of typewriter line */
#define CMAPSIZ 100             /* size of core allocation area */
#define SMAPSIZ 100             /* size of swap allocation area */
#define NCALL   20              /* max simultaneous time callouts */
#define NPROC   50              /* max number of processes */
#define NTEXT   40              /* max number of pure texts */
#define NCLIST  100             /* max total clist size */
#define HZ      60              /* Ticks/second of the clock */

/*
 * priorities
 * probably should not be
 * altered too much
 */

#define PSWP    -100
#define PINOD   -90
#define PRIBIO  -50
#define PPIPE   1
#define PWAIT   40
#define PSLEP   90
#define PUSER   100

/*
 * signals
 * dont change
 */

#define NSIG    20
#define         SIGHUP  1       /* hangup */
#define         SIGINT  2       /* interrupt (rubout) */
#define         SIGQIT  3       /* quit (FS) */
#define         SIGINS  4       /* illegal instruction */
#define         SIGTRC  5       /* trace or breakpoint */
#define         SIGIOT  6       /* iot */
#define         SIGEMT  7       /* emt */
#define         SIGFPT  8       /* floating exception */
#define         SIGKIL  9       /* kill */
#define         SIGBUS  10      /* bus error */
#define         SIGSEG  11      /* segmentation violation */
#define         SIGSYS  12      /* sys */
#define         SIGPIPE 13      /* end of pipe */

/*
 * fundamental constants
 * cannot be changed
 */

#define USIZE   16              /* size of user block (*64) */
#define NULL    0
#define NODEV   (-1)
#define ROOTINO 1               /* i number of all roots */
#define DIRSIZ  14              /* max characters per directory */

/*
 * structure to access an
 * integer in bytes
 */
struct
{
        char    lobyte;
        char    hibyte;
};

/*
 * structure to access an integer
 */
struct
{
        int     integ;
};

/*
 * Certain processor registers
 */
#define PS      0177776
#define KL      0177560
#define SW      0177570