HP 330 Service Information Manual page 162

Boot System Priority Control
Devices are searched in priority order for aSses. This priority order is determined by the boot
list. The boot list for the Boot ROM is:
1. Disc drives at select codes 0-31 on bus address 0, unit 0, volume 0
2. An SRM at node 0 at select code 21 on volume 8
:t
HP 98259 Bubble Memory Card on select code 30
4. HP 98255 EPROM Card "disc", unit 0
5. Remaining disc drives at select codes 0-31, bus addresses 0-7, units 0-16, volumes 0-7
(). Remaining SRMs at select codes 0-31
7. Remaining HP 98259 Bubble Memory Cards on select codes 0 through 29 and 31
8. Remaining HP 98255 EPROM Card "disc" units
Each device is allowed to have rnultiple aSses. Again, if the machine is unattended, it will boot
the first as found. If the computer is attended (i.e. a key was struck after the input human
interface was initialized), it will display all aSses found until one is selected and that one is
found.
For each category in the boot list, there is also an order of search based on address location.
In all cases, lower addresses are found first. This means a device at select code 0 will be found
before a device at select code 7. If a device has multiple addresses to locate it, then searching
is done at a local level first. For example, after looking at select code
7,
bus address 1, unit 1,
the Boot ROM will look at select code 7, bus address 1, unit 2 before going to select code 8.
The boot list pennits change and control of which as will be booted in the Unattended Mode.
Priorities used to establish the boot list are:
• High priority addresses before low priority addresses
• Local aSses before remote aSses (Local refers to dedicated devices and remote refers to
shared devices, i.e. an SRM)
• Flexible media before Hard media
• Small capacity devices before large capacity devices
146
Boot ROM Functions