1ad84aae1Smckusick/* 2*942a3603Smckusick * Copyright (c) 1980, 1986 Regents of the University of California. 3ad84aae1Smckusick * All rights reserved. The Berkeley software License Agreement 4ad84aae1Smckusick * specifies the terms and conditions for redistribution. 5ad84aae1Smckusick */ 6ad84aae1Smckusick 7ad84aae1Smckusick#ifndef lint 8*942a3603Smckusick_sccsid:.asciz "@(#)mttoggle.s 7.1 (Berkeley) 06/05/86" 9ad84aae1Smckusick#endif not lint 10529704e9Ssam 11529704e9Ssam/* 12529704e9Ssam * Prototype toggle in bootstrap code for mt type tapes. 13529704e9Ssam * If on anything but a 780 with a tape at drive 0 of mba 1 14529704e9Ssam * this will have to be repaired by patching mba and mt. 15529704e9Ssam */ 16529704e9Ssam movl mba,r10 17529704e9Ssam mull3 mt,$0x80,r11 18529704e9Ssam addl3 r11,r10,r11 19529704e9Ssam addl2 $0x400,r11 20529704e9Ssam movzbl $1,4(r10) 21529704e9Ssam movzbl $4,8(r11) /* drive zero, one record */ 22529704e9Ssam clrl 12(r10) /* set address to zero */ 23529704e9Ssam movl $0x80000000,0x800(r10) /* validate map register */ 24529704e9Ssam cvtwl $-512,16(r10) /* set byte count */ 25529704e9Ssam movzwl $512,20(r11) /* set byte count */ 26529704e9Ssam0: 27529704e9Ssam movl 0x44(r11),r0 28529704e9Ssam bbc $15,r0,0b 29529704e9Ssam movzbl $071,(r11) /* read forward, go */ 30529704e9Ssam halt 31529704e9Ssam .align 2 32529704e9Ssammba: .long 0x20012000 33529704e9Ssammt: .long 0 34