Setup Command 4: List/Change Automatic Boot Selection In Setup Table - Digital Equipment MicroPDP-11 Technical Manual

MicroPDP-11 Base Systems
TT1 blank
Device name
=
DU
Unit number = 4
CSR address
=
17760500
TT1 DU4 address 17760500
TT2 blank
Device name = DU
Unit number
=
5
CSR address
=
17760500
TT2 DU5 address 17760500
TT3 blank
Device name
=
Press the Return key for no change
2.5.4 Setup Command 4: List/Change Automatic Boot Selection in Setup Table
This command allows you to select the devices to be tried by the automatic boot
sequence. The table allows up to six entries. For each entry, you specify the device
mnemonic, the unit number, and the order to try to boot the devices. There are
three special single-letter device names:
A: MCSP automatic boot. Causes the ROM code to find up to eight MSCP devices
(units 0-7) at the standard CSR address. The ROM code first tries each removable
medium device in turn and then tries each fixed medium device.
You must select MSCP devices with nonstandard CSR addresses (setup command
3) individually.
B: An off-board boot. Causes the ROM code to boot from an off-board ROM at
address 17773000. The code checks that the ROM exists and that the first word is
not zero. Then it disables the internal code and jumps to address 17773000 of the
off-board ROM.
NOTE
Device name B implements a method of supporting non-Digital
Equipment Corporation boot devices on the Q22-Bus.
E: Exit automatic boot. Signals the ROM code that there are no other devices to
try. Follow the last device to be tried with this entry when fewer than six devices
exist.
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