mov    $idata,r0 / r0=base addr. of assembled directories.
	mov    $u.off,u.fofp / pointer to u.off in u.fofp (holds file
                             / offset)
1:
	mov    (r0)+,r1/r1=41.,...,47; "0" in the assembled directory
                       / header signals last
	beq    1f      / assembled directory has been written onto drum
	jsr    r0,imap / locate the inode map bit for i-node 'r1'
	bisb   mq,(r2) / set the bit to indicate the i-node is not
                       / available
	jsr    r0,iget / read inode 'r1' from disk into inode area of
                       / core and write modified i-node on drum (if any)
	mov    (r0)+,i.flgs / set flags in core image of inode from
                            / assembled directories header
	movb   (r0)+,i.nlks / set no. of links from header
	movb   (r0)+,i.uid / set user id of owner from header
	jsr    r0,setimod / set imod=1 to indicate inode modified; also,
                          / stuff time of modification into i-node
	mov    (r0)+,u.count / set byte count for write call equal to
                             / size of directory
	mov    r0,u.base / set buffer address for write to top of directory
	clr    u.off / clear file offset used in 'seek' and 'tell'
	add    u.count,r0 / r0 points to the header of the next directory
	jsr    r0,writei / write the directory and i-node onto drum
	br     1b / do next directory
	.endif

/ next 2 instructions not executed during cold boot.
	bis    $2000,sb0 / sb0 I/O queue entry for superblock on drum;
                         / set bit 10 to 1
	jsr    r0,ppoke / read drum superblock
1:
	tstb   sb0+1 / has I/O request been honored (for drum)?
	bne    1b / no, continue to idle.
1:
	decb   sysflg / mormally sysflag=0, indicates executing in system
	sys    exec; 2f; 1f / generates trap interrupt; trap vector =
                            / sysent; 0
	br     panic / execute file/etc/init

1:
	2f;0
2:
	</etc/init\0> / UNIX looks for strings term, noted by nul\0

panic:
	clr    ps
1:
	dec    $0
	bne    1b
	dec    $5
	bne    1b
	jmp    *$173700 / rom loader address