Specifications

Glossary
CNTRL* Control. This STD bus signal (pin 50) was used
in previous designs for special clock timing on
peripheral boards. It may also be used as an
interrupt request, INTRQ2*, on the backplane.
DCE Data Communication Equipment. One of two
possible orientations (DCE or DTE) for drivers
and receivers in the RS-232-C serial communi-
cations protocol.
DCU DMA Control Unit. Section of the CPU that
controls high speed data transfer between I/O
and memory devices.
DMA Direct Memory Access. Used for faster data
transfer rate when processing of I/O data on a
byte-by-byte basis is not required.
DTE Data Terminal Equipment. One of two possible
orientations (DCE or DTE) for drivers and
receivers in the RS-232-C serial communi-
cations protocol.
EOI End Of Interrupt. A byte sent to the interrupt
controller that signifies the interrupt level has
been serviced.
EPROM Erasable Programmable Read-Only Memory.
Memory is programmed and erased with ultra-
violet light.
D-2