Following are common NuBus terms:
- NuBus
A synchronous bus defined by Texas Instruments. It operates on a 10
MHz clock, with a full 32-bit data and address transfer. Apple's
implementation of NuBus does not include parity checks, but does add
interrupt lines to each of the Macintosh II NuBus slots.
- Bus master
At a given time, the bus device that initiates a transaction. Also, a
device with the ability to initiate a NuBus transaction by asserting
the START* line.
- Configuration ROM (also declaration ROM)
A 1M portion of the minor slot space. Each card must include
information within this space to identify itself to the Macintosh II
at startup. Items included here are the type of card, the location of
its driver, if present, the byte lanes it will use to communicate
with other NuBus devices, and slot resource data.
- Major slot space (also SuperSlot Space)
A portion of memory in the address range $9000 0000 to $F000 0000. By
convention, each card may use 256M in this space. A card in slot 1
would use from $9000 0000 to $9FFF FFFF, a card in slot 2 would use
addresses $A000 0000 to $AFFF FFFF, and so on. This address assignment
is not enforced; cards may use more than 256M of space, as long as
addressing conflicts do not occur between slots.
- Minor slot space (also Slot Space)
A portion of memory within the NuBus address space from $F000 0000 to
$FFFF FFFF. Each slot is assigned 16M of memory beginning at $Fs00
0000, where s is the card's physical slot location.
- Slave device
At a given time, a device that responds to a transaction. Also, a
device that cannot initiate a NuBus transaction or arbitrate requests
for bus mastership.