projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| e2f2e851 C |
1 | /* mttoggle.s 6.1 83/07/29 */ |
| 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 */ | |
| 18 | 0: | |
| 19 | movl 0x44(r11),r0 | |
| 20 | bbc $15,r0,0b | |
| 21 | movzbl $071,(r11) /* read forward, go */ | |
| 22 | halt | |
| 23 | .align 2 | |
| 24 | mba: .long 0x20012000 | |
| 25 | mt: .long 0 |