xref: /original-bsd/sys/vax/mdec/uttoggle.s (revision 883fb6be)
1/*
2 * Copyright (c) 1980, 1986 Regents of the University of California.
3 * All rights reserved.  The Berkeley software License Agreement
4 * specifies the terms and conditions for redistribution.
5 */
6
7#ifndef lint
8_sccsid:.asciz	"@(#)uttoggle.s	7.1 (Berkeley) 06/05/86"
9#endif not lint
10
11/*
12 * Prototype toggle in bootstrap code for ut type tapes.
13 * If on anything but a 780 with the drive on uba0
14 * this will have to be repaired by patching uba and umem.
15 */
16begin:
17	movl	uba,r1
18	movl	$0x80200000,0x800(r1)
19	clrl	0x804(r1)
20	movl	umem,r2
21	bisl2	$0172440,r2
22	movw	$0x04c0,26(r2)		/* set tape density & format */
23	mnegw	$512,6(r2)		/* set frame count */
24	mnegw	$256,2(r2)		/* set word count */
25	clrw	4(r2)			/* set bus address */
26	movw	$0x39,(r2)		/* set command and go */
27	halt
28	.align	2
29uba:	.long	0x20006000
30umem:	.long	0x2013e000
31