usr/src/sys/vax/rx50reg.h

/*
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *      @(#)rx50reg.h   7.1 (Berkeley) 7/9/88
 */

/*
 * RX50 registers.
 */

/*
 * The names below do not quite match the DEC documentation simply because
 * the names in the documentation are so bad.
 */
struct rx50device {
        u_short rxid;           /* identification */
        u_short reserved;
        u_short rxcmd;          /* command function reg */
        u_short rxtrk;          /* track */
        u_short rxsec;          /* sector */
        u_short rxcsc;          /* current sector */
        u_short rxict;          /* incorrect track (???) */
        u_short rxext;          /* extend command register */
        u_short rxedb;          /* empty data buffer (read) */
        u_short rxrda;          /* reset data address */
        u_short rxgo;           /* read to start current cmd */
        u_short rxfdb;          /* fill data buffer (write) */
};

#define RX50SEC         10      /* sectors per track */
#define RX50MAXSEC      800     /* 10 sectors times 80 tracks */

/*
 * Do the sector skew given the sector and track
 * number (it depends on both!).
 */
/*                      (((((s) / 5) + 2 * ((s) + (t))) % 10) + 1) */
#define RX50SKEW(s, t)  (((s) / 5) + "\1\3\5\7\11\1\3\5\7"[((s) + (t)) % 5])

/*
 * Values in the command function register.
 */
#define RXCMD_ERROR     0x80    /* error bit (composite?) */
#define RXCMD_READ      0x40    /* read command */
#define RXCMD_WRITE     0x70    /* write command */
#define RXCMD_RESET     0x20    /* reset command */
#define RXCMD_DONE      0x08    /* operation done (status) */
#define RXCMD_DRIVE0    0x00    /* select drive 0 (csa1) */
#define RXCMD_DRIVE1    0x02    /* select drive 1 (csa2) */