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 "@(#)mttoggle.s 7.1 (Berkeley) 06/05/86" 9#endif not lint 10 11/* 12 * Prototype toggle in bootstrap code for mt type tapes. 13 * If on anything but a 780 with a tape at drive 0 of mba 1 14 * this will have to be repaired by patching mba and mt. 15 */ 16 movl mba,r10 17 mull3 mt,$0x80,r11 18 addl3 r11,r10,r11 19 addl2 $0x400,r11 20 movzbl $1,4(r10) 21 movzbl $4,8(r11) /* drive zero, one record */ 22 clrl 12(r10) /* set address to zero */ 23 movl $0x80000000,0x800(r10) /* validate map register */ 24 cvtwl $-512,16(r10) /* set byte count */ 25 movzwl $512,20(r11) /* set byte count */ 260: 27 movl 0x44(r11),r0 28 bbc $15,r0,0b 29 movzbl $071,(r11) /* read forward, go */ 30 halt 31 .align 2 32mba: .long 0x20012000 33mt: .long 0 34