DEVNO - Hardware device number Hardware device number used in Sintran III, used in the IOX(T) instruction to read/write registers on a controller/interface. There are normally four registers assigned to each simple interface (a complex interface may have more registers assigned to it), but not all registers must necessarily be in use. A device which is both input and output capable (like a terminal interface) will have eight registers, one set for the input part and one set for the output part. This is the typical register usage:
DEVNO + 0
Read data from the interface (if input capable)
DEVNO + 1
Write data to the interface (if output capable)
DEVNO + 2
Read from the interface status register
DEVNO + 3
Write to the interface control register
DGA - ND-DGA ND-DGA chip on the ND-120 CPU, I/O Decode Gate Array.
Direction - Signal direction When a direction of a data signal is specified in a table, the controller (or the host) is always to the left and the device in action to the right (unless otherwise stated). F.ex the floppy disc drive signal INDEX is marked with ⇐ which means it is FROM the drive TO the controller.
DMA - Direct Memory Access GO FAR Wikipedia % for more information. DMA is a feature of computer systems that allows certain hardware subsystems to access main system memory independently of the CPU.
1.9 - Norsk Data glossary
