Commit | Line | Data |
---|---|---|
b1078c35 | 1 | /* |
0880b18e | 2 | * Copyright (c) 1980, 1986 Regents of the University of California. |
b1078c35 KM |
3 | * All rights reserved. The Berkeley software License Agreement |
4 | * specifies the terms and conditions for redistribution. | |
5 | */ | |
6 | ||
7 | #ifndef lint | |
0880b18e | 8 | _sccsid:.asciz "@(#)mttoggle.s 7.1 (Berkeley) %G%" |
b1078c35 | 9 | #endif not lint |
1ea832bd SL |
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 */ | |
26 | 0: | |
27 | movl 0x44(r11),r0 | |
28 | bbc $15,r0,0b | |
29 | movzbl $071,(r11) /* read forward, go */ | |
30 | halt | |
31 | .align 2 | |
32 | mba: .long 0x20012000 | |
33 | mt: .long 0 |