1/* mttoggle.s 4.1 83/02/16 */ 2 3/* 4 * Prototype toggle in bootstrap code for mt type tapes. 5 * If on anything but a 780 with a tape at drive 0 of mba 1 6 * this will have to be repaired by patching mba and mt. 7 */ 8 movl mba,r10 9 mull3 mt,$0x80,r11 10 addl3 r11,r10,r11 11 addl2 $0x400,r11 12 movzbl $1,4(r10) 13 movzbl $4,8(r11) /* drive zero, one record */ 14 clrl 12(r10) /* set address to zero */ 15 movl $0x80000000,0x800(r10) /* validate map register */ 16 cvtwl $-512,16(r10) /* set byte count */ 17 movzwl $512,20(r11) /* set byte count */ 180: 19 movl 0x44(r11),r0 20 bbc $15,r0,0b 21 movzbl $071,(r11) /* read forward, go */ 22 halt 23 .align 2 24mba: .long 0x20012000 25mt: .long 0 26